WO1998036335A2

WO1998036335A2 - Process control system using a layered-hierarchy control strategy distributed into multiple control devices

Info

Publication number: WO1998036335A2
Application number: PCT/US1998/001573
Authority: WO
Inventors: Mark Nixon; Robert B. Havekost; Larry O. Jundt; Dennis Stevenson; Michael G. Ott; Arthur Webb; Mike Lucas; James Hoffmaster; Ron Ottenbacher; Ken J. Beoughter; Roy Faltesek; Ken D. Krivoshein; John R. Shepard; Dan D. Christensen; Duncan Schleiss
Original assignee: Fisher-Rosemount Systems, Inc.
Priority date: 1997-02-14
Filing date: 1998-02-06
Publication date: 1998-08-20
Also published as: JP2012084162A; GB2336446A; JP2001512593A; WO1998036353A1; DE19882113T1; JP4934482B2; GB2336923A; JP5936180B2; GB2336923B; DE19882117T1; JP2007226825A; AU6045498A; WO1998036336A1; JP2001512598A; GB2336446B; DE19882116T5; JP2001512599A; GB9918410D0; JP2015092400A; AU6045598A

Abstract

A process controller (100) implements smart field device standards (132) and other bus-based architecture standards so that communications and control among devices are performed and the standard control operations are transparent to a user. The process controller implements and executes a standard set of function blocks (522) or control functions defined by a standard protocol so that standard-type control is achieved with respect to non-standard-type devices (12). The process controller enables standard devices (6) to implement the standard set of function blocks and control functions. The process controller implements an overall strategy as if all connected devices are standard devices by usage of a Fieldbus function block as a fundamental building block for control structures. Function blocks are defined to create control structures for all types of devices. A user defines the control strategy by building a plurality of function blocks and control modules (440) and downloading or installing user-specified portions of the control strategy into the Fieldbus devices and the non-Fieldbus devices. Thereafter, the Fieldbus devices automatically perform the downloaded portions of the overall strategy independently of other portions of the control stategy. The process control system includes a diagnostic monitoring and display functionality for viewing, in a coherent manner, diagnostic information relating to a process that operates over multiple devices and system components. The digital control system automatically senses when a new controller is attached to a network and determines the number and types of I/O Ports that are attached to the new controller. The digital control system program also includes an automatic configuration program that responds to sensing of a new controller by automatically configuring the input/output (I/O) subsystem. Upon connection of the device, the device is automatically sensed and configured using the database configuration information, without setting of physical switches or node address information on the devices. The digital control system with a predetermined configuration automatically senses the connection to a network of a digital device that is not included in the predetermined configuration. The process control system includes a user interface (300) which supports multiple IEC-1131 standard control languages and user-selection from among the control languages. From a single application routing, a user selects a control language from among a plurality of control languages including, for example, Function Blocks, Sequential Function Charts, Ladder Logic and Structural Text, to implement a control strategy. The process control system includes an alarm and event monitoring and display system for which various users of the system can easily prioritize the alarm and event information that is displayed.

Description

PROCESS CONTROL SYSTEM USING A LAYERED-HIERARCHY CONTROL STRATEGY DISTRIBUTED INTO MULTIPLE CONTROL DEVICES

TECHNICAL FIELD

This invention relates to process control systems. More specifically, the present invention relates to a process control system which monitors and uniformly displays diagnostic information of devices of multiple different types.

BACKGROUND ART

Present-day process control systems use instruments, control devices and communication systems to monitor and mapφruate control elements, such as valves and switches, to maintain at selected target values one or more process variables, mcluding temperature, pressure, flow and the like. The process variables are selected and controlled to achieve a desired process objective, such as attaining the safe and efficient operation of machines and equipment utilized in the process. Process control systems have widespread application in the automation of industrial processes such as the processes used in chemical, petroleum, and manufacturing industries, for example.

Control of the process is often implemented using microprocessor-based controllers, computers or workstations which monitor the process by sending and receiving commands and data to hardware devices to control either a particular aspect of the process or the entire process as a whole. The specific process control functions that are implemented by software programs in these microprocessors, computers or workstations may be individually designed, modified or changed through programming while requiring no modifications to the hardware. For example, an engineer might cause a program to be written to have the controller read a fluid level from a level sensor in a tank, compare the tank level with a predetermined desired level, and then open or close a feed valve based on whether the read level was lower or higher than the predetermined, desired level. The parameters are easily changed by displaying a selected view of the process and then by modifying the program using the selected view. The engineer typically would change parameters by displaying and modifying an engineer's view of the process.

In addition to executing control processes, software programs also monitor and display a view of the processes, providing feedback in the form of an operator's display or view regarding the status of particular processes. The monitoring software programs also signal an alarm when a problem occurs. Some programs display instructions or suggestions to an operator when a problem occurs. The operator who is responsible for the control process needs to view the process from his point of view. A display or console is typically provided as the interface between the microprocessor based controller or computer performing the process control function and the operator and also between the programmer or engineer and the microprocessor based controller or computer performing the process control function. Systems that perform, monitor, control, and feed back functions in process control environments are typically implemented by software written in high-level computer programming languages such as Basic, Fortran or C and executed on a computer or controller. These high-level languages, although effective for process control programming, are not usually used or understood by process engineers, maintenance engineers, control engineers, operators and supervisors. Higher level graphical display languages have been developed for such personnel, such as continuous function block and ladder logic. Thus each of the engineers, maintenance personnel, operators, lab personnel and the like, require a graphical view of the elements of the process control system that enables them to view the system in terms relevant to their responsibilities.

For example, a process control program might be written in Fortran and require two inputs, calculate the average of the inputs and produce an output value equal to the average of the two inputs. This program could be termed the AVERAGE function and may be invoked and referenced through a graphical display for the control engineers. A typical graphical display may consist of a rectangular block having two inputs, one output, and a label designating the block as AVERAGE. A different program may be used to create a graphical representation of this same function for an operator to view the average value. Before the system is delivered to the customer, these software programs are placed into a library of predefined user selectable features. The programs are identified by function blocks. A user may then invoke a function and select the predefined graphical representations to create different views for the operator, engineer, etc. by selecting one of a plurality of function blocks from the library for use in defining a process control solution rather than having to develop a completely new program in Fortran, for example.

A group of standardized functions, each designated by an associated function block, may be stored in a control library. A designer equipped with such a library can design process control solutions by interconnecting, on a computer display screen, various functions or elements selected with the function blocks to perform particular tasks. The microprocessor or computer associates each of the functions or elements defined by the function blocks with predefined templates stored in the library and relates each of the program functions or elements to each other according to the interconnections desired by the designer. Ideally, a designer could design an entire process control program using graphical views of predefined functions without ever writing one line of code in Fortran or other high-level programming language.

One problem associated with the use of graphical views for process control programming is that existing systems allow only the equipment manufacturer, not a user of this equipment, to create his own control functions, along with associated graphical views, or modify the predefined functions within the provided library.

New process control functions are designed primarily by companies who sell design systems and not by the end users who may have a particular need for a function that is not a part of the standard set of functions supplied by the company. The standardized functions are contained within a control library furnished with the system to the end user. The end user must either utilize existing functions supplied with the design environment or rely on the company supplying the design environment to develop any desired particular customized function for them. If the designer is asked to modify the parameters of the engineer's view, then all other views using those parameters have to be rewritten and modified accordingly because the function program and view programs are often developed independently and are not part of an integrated development environment. Clearly, such procedure is very cumbersome, expensive, and time-consuming.

Another problem with existing process control systems is a usage of centralized control, typically employing a central controller in a network, executing a program code that is customized for specialized, user-defined control tasks. As a result, the process control systems are typically constrained to a particular size and difficult to adapt over time to arising needs. Similarly, conventional process control systems are inflexible in configuration, often requiring a complete software revision for the entire system when new devices are incorporated. Furthermore, the conventional process control systems tend to be expensive and usually perform on the functions initially identified by a user or a system designer that are only altered or reprogrammed to perform new functions by an expert who is familiar with the entire control system configuration and programming.

What is needed is a uniform or universal design environment that can easily be used, not only by a designer or manufacturer but also a user, to customize an existing solution to meet his specific needs for developing process control functions. What is further needed is a personal computer-based process control system that is easily implemented within substantially any size process and which is updated by users, without the aid of the control system designer, to perform new and different control functions.

Many process control systems include local field devices such as valves, motors, regulators and the like which are responsive to specific control protocols, such as Profibus, Fieldbus, CAN and the like, to implement various control function routines. Accordingly, these controllers are responsive to certain standard control protocols to implement control functionality in the field. The use of such standard control signal protocols can reduce the time and effort of developing a control system because a designer can use the same types of control signals from all devices responsive to the control protocol.

However, certain control devices are not responsive to standard control protocols. These devices are often responsive to other types of control signals such as digital ON/OFF signals, analog current signals or analog voltage signals. A system designer either has to avoid using field devices that are nonresponsive to an installed protocol, or develop systems that operate under one or more protocols. Thus, present day processing systems disadvantageously lack a capability to utilize both standard protocol control devices and devices that do not respond to control signals defined under the standard protocols.

What is needed is a process control system that controls both devices that are defined using a standard protocol and other, non-protocol devices in a manner that is transparent to the user of the process control system. Systems that perform, monitor, control, and feed back functions in process control environments are typically implemented by software written in high-level computer programming languages such as Basic, Fortran or C and executed on a computer or controller. These high-level languages, although effective for process control programming, are not usually used or understood by process engineers, maintenance engineers, control engineers, operators and supervisors. Higher level graphical display languages have been developed for such personnel, such as continuous function block and ladder logic. Thus each of the engineers, maintenance personnel, operators, lab personnel and the like, require a graphical view of the elements of the process control system that enables them to view the system in terms relevant to their responsibilities.

A further problem with existing process control systems is that the physical implementation of different systems is highly variable, including control devices and field devices that have a wide range of "intelligence". For example, some field devices, such as valves, motors and regulators, may have no computational or control capability. Other field devices may have a high level of control autonomy. Still other devices may have some computational strength, but not a sufficient amount to accomplish a desired control task.

What is needed is a uniform or universal design environment that can easily be used, not only by a designer or manufacturer but also a user, to customize a control process to the physical constraints of the process, utilizing control capabilities various controllers and devices, supplementing these control capabilities when desired and distributing control functionality flexibly throughout the process control system to meet specific needs for developing process control functions. What is further needed is a personal computer-based process control system that is easily implemented within substantially any size process and which is updated by users, without the aid of the control system designer, to perform new and different control functions by distributing these control functions throughout the control system including all central, intermediate and peripheral levels.

Diagnostic information is one type of information that is useful to monitor and display in a process control system. However with the various types of devices in a process control system, including a wide variety of field devices, diagnostic information is not generally monitored in a consistent manner from one device to the next. Furthermore, important diagnostic information typically relates to the interaction of multiple portions of the control system, for example, the combined operations of a controller and device or multiple devices and controllers. Diagnostic information relating to multiple circuits in a system is typically not handled by existing process control systems. Diagnostic information is most useful when related to the various control operations that are occurring when the diagnostic information is monitored. Conventional process control systems typically access and display diagnostic information with no relation to the control operations or control schemes that are functioning during diagnostic testing.

One problem associated with the use of graphical views for diagnostic displays is that existing systems allow only the equipment manufacturer, not a user of this equipment, to define the diagnostic information to be monitored, along with associated graphical views, or modify the predefined diagnostic functions within the provided library.

What is needed is a uniform or universal design environment that can easily be used, not only by a designer or manufacturer but also a user, to customize monitoring and display of diagnostic operations for a variable number and type of devices and components of a process control system. What is further needed is a personal computer-based process control system that includes a flexible diagnostic monitoring and display functionality that is easily implemented within substantially any size process and which is updated by users, without the aid of the control system designer, to monitor and display diagnostic information for various combinations of process field devices.

In a conventional process conttol system, the local field devices are typically configured in the field, often by individually programming the local field devices using a hand-held field programmer. Individual programming of the field devices is time consuming and inefficient and often leads to incompatibilities between the device configuration and the configuration of other devices and controllers in the process conttol system since a global view of the system is more difficult to sustain when individual devices are programmed independently. Usage of individual programming devices is inconvenient since multiple different programming devices typically must be used to program respective different field devices.

Furthermore, local device failures, including temporary failures or local power disruptions, interrupt operations of the entire conttol system, sometimes causing extended downtime since each failing device must be reconfigured locally.

What is needed is a process conttol system that allows individual field devices to be configured without local, independent programming. What is further needed is a process control system which allows configuration of the global system from a location remote from the local field devices so that a compatible global configuration is achieved while allowing peripheral elements which are configured in a suitable global manner, to operate independently to achieve control functionality.

Configuration of the global system is based on parameters that describe the particular field devices that make up the system. However, the conttol protocols for communicating with the field devices may be insufficient to convey parameters that are sufficient to configure the system. For example, the system management specification of the Fieldbus protocol defines three states for a device including an INITIALIZED state, an UNINITIALIZED state, and a system management operational (SM OPERATIONAL) state. The three defined states are sufficient to describe the behavior of a device from the perspective of the system management, but are not adequate for describing a device from the perspective of either the fieldbus interface or software engineering tools for analyzing, controlling, or displaying the status of a device. This insufficiency is highly notable when configuration involves the operation of commissioning a device that is attached to the Fieldbus link in an UNTNITIALIZED state.

What is further needed is a process conttol system that differentiates between Fieldbus device states to support automatic sensing of devices and online address assignment of devices.

Several conttol languages have been developed under an IEC-1131 standard which assist a user in implementing a conttol sttategy. These control languages include function blocks, sequential function charts, ladder logic and structured text. Each of these languages is directed to a particular type of user, including conttol engineers, conttol system designers, technicians, operators and maintenance workers. These users have widely different levels and areas of experience, training and expertise. Different users typically view control systems from greatly different perspectives and seek a solution to very different problems, expressed in different manners. For example, a conttol configuration view of a conttol system designer may be nonsense to a maintenance worker and vice-versa.

What is needed is a user interface which flexibly presents a configuration in a manner that is most understandable and useful to a particular type of user.

Alarm and event information is one type of information that is highly critical to monitor and display in a process conttol system. However with the various types of devices in a process conttol system, including a wide variety of field devices, alarm information is not generally monitored in a useful manner. For example, very different urgencies may exist with respect to a particular alarm. Some alarm conditions may be indicative merely that some routine servicing should take place without urgency. Other alarm conditions require immediate attention. Certain devices in the process control system may measure highly critical conditions while other devices monitor much less urgent information. Furthermore, important some alarm conditions may relate to information the interaction of multiple portions of the conttol system, for example, the combined operations of a controller and device or multiple devices and controllers. Alarm conditions relating to multiple circuits and devices in a system are typically not handled by existing process conttol systems.

Alarm and event information is most useful when related to the various conttol operations that are occurring when the conditions are monitored. Conventional process conttol systems typically access and display alarm information with no relation to the conttol operations or conttol schemes that are functioning during diagnostic testing. Conventional process conttol systems generally do not have a consistent system for setting priority of different alarm conditions and events. One problem associated with the use of graphical views for alarm and event displays is that existing systems allow only the equipment manufacturer, not a user of this equipment, to define the alarms and events to be monitored, along with associated graphical views, or modify predefined event priorities. Different types of users may need to visualize different aspects of the process conttol system. For example, some users have a capability to change only some operating aspects of the conttol system. These users should have access to condition information which they can control while for other events that may be controlled by another user, alarm information is not urgently needed.

What is needed is a uriiform or universal design environment that can easily be used, not only by a designer or manufacturer but also a user, to prioritize display of alarm and event information.

DISCLOSURE OF INVENTION

In accordance with the present invention, a process controller implements smart field device standards and other bus-based architecture standards so that communications and control among devices are performed so that the standard conttol operations are transparent to a user. The process controller allows attachment to a theoretically and substantially unlimited number and type of field devices including smart devices and conventional non-smart devices. Control and communication operations of the various numbers and types of devices are performed simultaneously and in parallel.

The described design environment enables a process conttol designer or user to modify a standard process conttol function or create a unique customized process conttol function and create the graphical views to be associated with the modified or newly created process control function, all within a common environment. The design environment includes a common interface for both the creation of the function and for its associated engineers, operators, lab and maintenance personnel or other desired users such that when the engineer's function is modified or created, the modification or creation manifests itself in all other graphical views of the function. In addition, the design environment has a common database structure of attributes and methods and the graphics associated with the process conttol function to allow modified or created process conttol functions to be represented in whatever graphical methodology that is desired or required by the designer, whether by ladder logic, continuous function block or other design languages required by the various engineer, operator, lab, and maintenance personnel as other desired graphical views.

Many advantages are achieved by the above-described system and operating method. One advantage is that conttol operations are dispersed throughout the conttol system, avoiding the inflexibility that arises from centralized conttol. Another advantage is that the conttol system is personal-computer (PC) based and, therefore, inexpensive in comparison to mainframe based systems, easily upgraded as additional processes are added to the system, and conveniently operated by multiple users. The PC-based conttol is further advantageous in allowing user-friendly programming and display platforms such as Windows 95™ and Windows NT™. In accordance with the present invention, a process controller implements and executes a standard set of function blocks or conttol functions defined by a standard protocol so that standard-type conttol is achieved with respect to non-standard-type devices. The process controller enables standard devices to implement the standard set of function blocks and conttol functions. The process controller implements an overall sttategy as if all connected devices are standard devices by usage of a function block as a fundamental building block for conttol structures. These function blocks are defined to create conttol structures for all types of devices.

Many advantages are gained by the described system and method. One advantage is that the system is highly uniform, whether attached devices are standard protocol devices or nonstandard devices, thereby improving system reliability. A further advantage is that system development costs are greatly reduced by handling various devices in a uniform manner. Another advantage is that a wide range of different field devices are supported so that intelligent devices utilize the intelligent capabilities and "dumb" devices are controlled by other controllers. An additional advantage is that a software routine performing a particular routine is highly re-usable, improving software reliability.

In accordance with the present invention, a process controller implements an overall, user-developed conttol strategy in a process conttol network that includes distributed controller and field devices, such as Fieldbus and non-Fieldbus devices. A user defines the conttol sttategy by building a plurality of function blocks and control modules and downloading or installing user-specified portions of the conttol strategy into the Fieldbus devices and the non-Fieldbus devices. Thereafter, the Fieldbus devices automatically perform the downloaded portions of the overall strategy independently of other portions of the conttol sttategy. For example in a process control system that includes distributed field devices, controllers and workstations, portions of the conttol sttategy downloaded or installed into the field devices operate independently of and in parallel with the control operations of the controllers and the workstations, while other conttol operations manage the Fieldbus devices and implement other portions of the control sttategy.

The described process conttol system and operating method has many advantages. One advantage is that the system supplies a uniform, universal design environment for users of many various expertise, experience and training levels to customize a conttol process to the physical constraints of the process. A further advantage is that the described system uses conttol capabilities of various controllers and devices, supplementing these control capabilities when desired and distributing conttol functionality flexibly throughout the process conttol system as needed. Another advantage is that the process conttol system is easily based on a personal computer-based design which is easily implemented within substantially any size process and which is updated by users, without the aid of the conttol system designer, to perform new and different control functions. This flexibility is achieved by distributing conttol functions throughout the conttol system including all central, intermediate and peripheral levels.

In accordance with the present invention, a process conttol system includes a diagnostic monitoring and display functionality for viewing, in a coherent manner, diagnostic information relating to a process that operates over multiple devices and system components. Although the multiple devices and system components typically encompass widely different device types and operational standards, the process conttol system incorporates diagnostic information relating to all devices and presents this information to a system user in a uniform manner so that an operating conttol strategy and the diagnostic information are presented as though all conttol actions and diagnostic information were performed or generated at a single location. A user-defined diagnostic program is assembled as a set of function blocks and conttol modules and represented as a set of layers of interconnected conttol objects identified as modules which include informational structures accessed as attributes. Information is accessed using device hierarchy attribute addressing, supporting direct addressing of I/O signals from modules, bypassing the use of I/O function blocks and avoiding I/O function block behavior.

Many advantages are achieved using the described process conttol method. One advantage is that the conttol scheme and the diagnostic monitoring are configured in the system in the same manner, saving system resources and improving system reliability. Another advantage is that configuration of the diagnostics is highly versatile, achieving a wide range of diagnostic behaviors. A further advantage is that the same display objects and procedures are used to display all types of information including configuration information, status information, diagnostics and virtually any other information generated or stored in the system.

In accordance with the present invention, a digital conttol system automatically senses when a new controller is attached to a network and determines the number and types of I/O Ports that are attached to the new controller. The digital conttol system formats and displays the I/O Port information upon request by a user. The digital conttol system program also includes an automatic configuration program that responds to sensing of a new controller by automatically configuring the input/output (I/O) subsystem. The user adds a new controller without setting any physical switches or nodes. A user optionally supplies configuration information for a device into a database, prior to connection of a device. Upon connection of the device, the device is automatically sensed and configured using the database configuration information, without setting of physical switches on the devices.

In accordance with another aspect of the invention, a method of automatically sensing a connection of a controller to a network and incorporating the controller into a network operating system includes the steps of connecting a controller to the network, sending a request from the controller to confirm a network address assignment, the request being accompanied by the controller media access conttol (MAC) address, a network configuration service receiving the request to confirm and responding. The network configuration service responds by performing the steps of searching a table of configured devices for a matching MAC address and, when the MAC address matches, generating device and network information. The device and network information includes a network address from a device table. When the MAC address does not match, network configuration service generates device and network information including a network address from MAC address-based default information and adds the default information to the device table. When the MAC address does not match, the network configuration service further performs the step of assigning the connected controller under user conttol either as a new device added to the device table or as a device configuration previously existing in the device table.

Many advantage are achieved by the described system and method. One advantage is that field devices are programmed from a remote location so that individual field setting of the devices, using a local setting device, is not necessary. Central programmability is highly useful to reduce system management costs and for reducing downtime of a process conttol system. A further advantage is that configuration of the entire system, rather setting of individual devices, leads to a system in which individual system settings are highly compatible.

In accordance with an aspect of the present invention, a conttol system controls one or more interconnected devices according to a defined conttol configuration. The conttol system automatically senses a device that is connected to the conttol system but not included in the control configuration definition. The conttol system supplies initial interconnect information to the connected device sufficient to upload configuration parameters from the device to the conttol system.

In accordance with a further aspect of the present invention, a digital conttol system with a predetermined configuration automatically senses the connection to a network of a digital device that is not included in the predetermined configuration. The digital device is assigned temporary address information and placed in a temporary state, called a standby state, in which the digital device supplies information to the digital conttol system allowing a user to access the digital device including access of device information and configuration parameters. Using the device information and configuration parameters, a user selectively commissions the digital device by assigning a physical device tag, and a device address, and installing a conttol strategy to the digital device, thereby placing the digital device in an operational state in communication with the digital conttol system. In the standby state, a user interrogates to determine the type of device that is attached, determines the role of the device in the context of the digital conttol system, assigns a physical device tag that assigns the determined role to the device, and verifies connection of the device to the network. Also in the standby state, the user initiates other applications applied to the device, including calibration of the device and configuring the device within the overall conttol scheme of the digital conttol system.

In accordance with another aspect of the present invention, a control system differentiates between Fieldbus device states beyond the states defined according to the Fieldbus standard specification. The conttol system sets a physical device tag equal to the device identification (ID) for the devices that do not have tags, while the device is autosensed. A device attached to the Fieldbus link with the physical device tag set equal to the device LD is controlled in the manner of an UNINTTIALIZED device.

In accordance with an aspect of the present invention, automatic sensing of field devices is extended beyond a conventional input output level to the configuration of Fieldbus devices by a digital conttol system. Many advantages are achieved by the described system and method. One advantage is that configuration of a control system is greatly facilitated. The physical connection of a device to the network automatically initiates inclusion of the connected device into the conttol system. The described system and method advantageously facilitates conformity between the configuration of a network and the physical interconnections of the network that serves as the basis for the configuration. The described system and method assist programming of field devices from a remote location so that individual field setting of the devices, using a local setting device, is not necessary. The system and method support central programmability is highly useful to reduce system management costs and for reducing downtime of a process control system. A further advantage is that configuration of the entire system, rather setting of individual devices, leads to a system in which individual system settings are highly compatible.

In accordance with the present invention, a process control system includes a user interface which supports multiple IEC-1131 standard control languages and user-selection from among the conttol languages. From a single application routine, a user selects a conttol language from among a plurality of conttol languages including, for example, Function Blocks, Sequential Function Charts, Ladder Logic and Structured Text, to implement a conttol strategy.

In accordance with another aspect of the present invention, a method for configuring a process control environment controlled by a computer system having a processor connected to a display device includes the step of providing a plurality of instructional sections. An instructional section sets forth information relating to configuring the process conttol environment. The method also includes the steps of selecting a conttol language editor for defining a process control environment configuration, displaying on the display device a sequence of configuration screen presentations relating to the instruction sections as directed in terms of the selected conttol language editor; and guiding a user through the configuration of the process control environment via the sequence of configuration screen presentations.

Many advantages are attained by the described system and method. One advantage is that many different users are supported by the system so that users having a wide range of expertise and experience can easily use the system. Furthermore, the system is highly useful for a single user to tailor various aspects of the system using a most appropriate language for a particular system aspect.

In accordance with the present invention, a process control system includes an alarm and event monitoring and display system for which various users of the system can easily prioritize the alarm and event information that is displayed. The alarm and event configuration is highly flexible and is configured by a user to display particular events in a hierarchical manner, as directed by the user. The user sets a desired alarm priority, selecting high importance alarms for more urgent display and annunciation and rendering a lower display status to less urgent events. At log-on, a particular system user is associated with a display configuration for displaying alarm and event information that is pertinent to that user and the process conttol system is automatically "primed" with current alarms and initiate process information about new alarm and event occurrences. Many advantages are achieved using the described process control method. One advantage is that alarm information is presented to a user who can best use that information in a manner directed by the user. Another advantage is that a user attains access to the appropriate information automatically, at log-on. A further advantage is that the information stream is "primed" when a user logs on so that pertinent alarm events begin immediate accumulation for that user.

BRIEF DESCRIPTION OF DRAWINGS

The features of the invention believed to be novel are specifically set forth in the appended claims. However, the invention itself, both as to its structure and method of operation, may best be understood by referring to the following description and accompanying drawings.

FIGURES 1A, IB and IC illustrate a screen display, a first schematic block diagram and a second schematic block diagram, respectively, process control systems in accordance with a generalized embodiment of the present invention which furnishes a capability to create a new conttol template and a capability to modify an existing control template for only one view, such as an engineering view.

FIGURE 2 is a schematic block diagram showing the process conttol environment in a configuration implementation and a run-time implementation.

FIGURE 3 is a block diagram illustrating a user interface for usage with both configuration and run-time models of the process control environment.

FIGURE 4 is a schematic block diagram which depicts a hierarchical relationship among system objects of a configuration model in accordance with an embodiment of the present invention.

FIGURE 5 is a schematic block diagram which depicts a configuration architecture that operates within the hierarchical relationship illustrated in FIGURE 4.

FIGURE 6 is a block diagram illustrating an example of an elemental function block, which is one type of system object within the configuration model definition.

FIGURE 7 is a block diagram depicting an example of a composite function block, which is another type of system object within the configuration model definition.

FIGURE 8 is a block diagram illustrating an example of a conttol module, which is another type of system object within the configuration model definition.

FIGURE 9 is a block diagram showing a module instance, specifically a control module instance, which is created in accordance with the control module definition depicted in FIGURE 8.

FIGURE 10 is a flow chart which shows an example of execution of a conttol module at run-time. FIGURE 11 is a flow chart which shows an example of a module at a highest layer of a conttol structure.

FIGURE 12 is a block diagram which illusttates an object-oriented method for installing a process I/O attribute block into a PIO device.

FIGURE 13 is a block diagram depicting an object-oriented method for linking a conttol module input attribute to a PIO attribute.

FIGURE 14 is a block diagram showing an object-oriented method for linking a conttol module output attribute to a PIO attribute.

FIGURE 15 is a block diagram showing an object-oriented method for reading values of contained PIO attributes.

FIGURE 16 is a block diagram which illusttates an organization of information for an instrument signal tag.

FIGURE 17 is a flow chart illustrating a method for bootsttap loading a conttol system throughout a network in the process conttol environment.

FIGURE 18 is an object communication diagram illustrating a method for creating a device connection for an active, originating side of the connection.

FIGURE 19 is an object communication diagram illustrating a method for creating a device connection for a passive, listening side of the connection.

FIGURE 20 is an object communication diagram illustrating a method for sending request response messages between devices.

FIGURE 21 is an object communication diagram illustrating a method of downloading a network configuration.

FIGURE 22 is a pictorial view of a front-of-screen display which illusttates a flowchart of the operations of a diagnostic display routine.

FIGURE 23 is an object communication diagram illustrating a method for one device to check whether another device exists on a network.

FIGURE 24 is an object communication diagram illustrating a method for requesting device communications diagnostics. FIGURE 25 is an object communication diagram illustrating a method for requesting device connection communications diagnostics.

FIGURE 26 illustrates a method for automatically sensing and incorporating a controller/ multiplexer into a run-time system.

FIGURE 27 is a flow chart illusttates steps of an automatic configuration routine for configuring a physical I/O device.

FIGURE 28 is a pictorial view of a front-of-screen display for a graphical user interface (GUI) displaying a system configuration.

FIGURE 29 is a state transition diagram illustrating various states of a field device.

FIGURE 30 is a flow chart illustrating a first operation of commissioning a new device.

FIGURE 31 is a flow chart illustrating a second operation of commissioning an unbound.

FIGURE 32 is a flow chart illustrating a third operation of decommissioning a device.

FIGURE 33 is a flow chart illustrating a fourth operation of attaching a commissioned device without enablement of operational powerap.

FIGURE 34 is a flow chart illustrating a fifth operation of replacing a device.

FIGURE 35 is a flow chart illustrating a sixth operation of attaching an UNRECOGNIZED device.

FIGURE 36 is a flow chart illustrating a seventh operation of decommissioning an unrecognized device.

FIGURE 37 is a flow chart illustrating an eighth operation of placing a decommissioned device in a standby condition.

FIGURE 38 is a schematic block diagram which illusttates a program structure of a process conttol configuration program for defining a process configuration using a plurality of conttol languages.

FIGURES 39A through 39E are multiple screen presentations showing configuration, selection and choice screens that are invoked by a configuration program during operation of a configuration operation using a functional block conttol language and a sequential function chart control language.

FIGURE 40 is an object model showing object relationships of various objects for handling alarm and event functions. FIGURE 41 is a state transition diagram which depicts alarm attribute states.

FIGURE 42 is a context diagram showing a context for defining an alarm event with respect to a control module.

FIGURE 43 is an object communication diagram illustrating a method for performing an attribute write operation that evokes an "in alarm" status.

MODES FOR CARRYING OUT THE INVENTION

Referring to FIGURE 1A, a conttol system is shown. In general, the system 1 includes a main processing device, such as personal computer 2, that is connected to a local area network ("LAN") 3 via a local area network card. Although any local area network protocol may be used, a non-proprietary ethernet protocol is beneficial in many applications because it allows for communications with the local area network 3. The local area network 3 is dedicated to carrying control parameters, conttol data and other relevant information concerned in the process control system. As such, the LAN 3 may be referred to as an area controlled network or ACN 3. The ACN 3 may be connected to other LANs for sharing information and data via a hub or gateway without affecting the dedicated nature of ACN 3.

In accordance with standard ethernet protocol, a plurality of physical devices may be connected to the ACN 3 at various "nodes." Each physical device connected to the ACN 3 is connected at a node and each node is separately addressable according the LAN protocol used to implement ACN 3.

To establish a redundant system, it may be desirable to construct ACN 3 from two or more ethernet systems such that the failure of a single ethernet or LAN system will not result in the failure of the entire system. When such "redundant ethernets" are used the failure of one ethernet LAN can be detected and an alternate ethernet LAN can be mapped in to provide for the desired functionality of ACN 3.

The main personal computer ("PC") A forms a node on the ACN 3. The PC 2 may, for example, be a standard personal computer running a standard operating system such as Microsoft's Window NT system. Main PC 2 is configured to generate, in response to user input commands, various conttol routines that are provided via the ACN 3 to one or more local controllers identified as element 4 and 5 which implement the conttol strategy defined by the conttol routines selected and established in main PC 2. Main PC 2 may also be configured to implement direct conttol routines on field devices such as pumps, valves, motors and the like via transmission across the ACN 3, rather than through a local controller 4 or 5.

Local conttollers 4 and 5 receive control routines and other configuration data through the ACN 3 from PC 2. The local conttollers then generate signals of various types to various field devices (such as pumps, motors, regulator valves, etc.) 6 through 15 which actually implement and perform physical steps in the field to implement the conttol system established by the routines provided by PC 2. __1?_

Two types of field devices may be connected to local conttoller 4 and 5 including field devices 6 through 10 which are responsive to specific conttol protocol such as FieldBus, Profibus and the like. As those in the art will appreciate, there are standard conttol protocols (e.g. FieldBus) according to which specific protocol instructions are provided to a protocol-friendly field devices (e.g., a Fieldbus field devices) will cause a conttoller located within the field device to implement a specific function corresponding to the protocol function. Accordingly, field devices 6 through 11 receive protocol specific (e.g., FieldBus) conttol commands from either the local controllers 4 and 5 or the personal computer 2 to implement a field device- specific function.

Also connected to local conttollers 4 and 5 are non-protocol field devices 12 through 15, which are referred to as non-protocol because they do not include any local processing power and can respond to direct conttol signals. Accordingly, field devices 12 through 15 are not capable of implementing functions that would be defined by specific conttol protocol such as the FieldBus conttol protocol.

Functionality is supplied to allow the non-protocol field devices 12 through 15 to operate as protocol-friendly (e.g., FieldBus specific) devices 6 through 11. Additionally, this same functionality allows for the implementation of the protocol-specific conttol routines to be distributed between the local field devices 6 through 11, the local conttollers 4 and 5 and the personal computer 2.

The distribution of protocol-specific conttol routines is illustrated in more detail in FIGURE IB. FIGURE IB refers to one portion of the system shown in FIGURE 1A, specifically the personal computer 2, the ethernet 3, local conttoller 4, a smart field device 6 and a dumb device 12, in greater detail.

Personal computer 2 includes program software routines for implementing standard functional routines of a standard conttol protocol such as the FieldBus protocol. Accordingly, personal computer 2 is programmed to receive FieldBus commands and to implement all of the functional routines for which a local field device having Fieldbus capabilities could implement. The ability and steps required to program personal computer 2 to implement FieldBus block functionality will be clearly apparent to one of ordinary skill in the art.

Connected to personal computer 2 by the ethernet 3 is local conttoller 4. Local conttoller 4 includes a centtal processing unit connected to a random access memory which provides conttol signals to configure the central processing unit to implement appropriate operational functions. A read only memory is connected to the random access memory. The read only memory is programmed to include conttol routines which can configure the centtal processing unit to implement all of the functional routines of a standard conttol protocol such as FieldBus. Personal computer 2 sends signals through ethernet 3 to the local conttoller 4 which causes one, more or all of the programmer routines in the read only memory to be transferred to the random access memory to configure the CPU to implement one, more or all of the standard control protocol routines such as the FieldBus routines. The smart field device 6 includes a centtal processing unit which implements certain conttol functions. If the devices is, for example, a FieldBus device then the centtal processing unit associated with the field device 6 is capable of implementing all of the FieldBus functionality requirements.

Because the local controller 4 has the ability to implement FieldBus specific controls, conttoller 4 operates so that non-protocol device 12 acts and is operated as a FieldBus device. For example, if a conttol routine is running either in personal computer 2 or on the CPU of local conttoller 4, that conttol routine can implement and provide FieldBus commands to FieldBus device 6 and non-protocol device 12, operating as a Fieldbus device. Since field device 6 is a FieldBus device, device 6 receives these commands and thereby implements the control functionality dictated by those commands. Non-protocol device 12, however, works in conjunction with the centtal processing unit of local conttoller 4 to implement the FieldBus requirements such that the local conttoller in combination with the field device implements and operates FieldBus commands.

In addition to allowing non-FieldBus device 12 to act and operate as a FieldBus device, the described aspect allows for distribution of FieldBus conttol routines throughout the system 1 shown in FIGURE 1A. For example, to the extent that a conttol routine initially requests field device 6 to implement more than one FieldBus control routine, the system 1 allows for conttol to be divided between the local controller 4 and the local conttoller 5 such that a portion of the FieldBus conttol routines are being implemented by local controller 5 and other FieldBus routines are implemented by the use of the FieldBus routines stored on local conttoller 4. The division of FieldBus routine implementation may allow for more sophisticated and faster control and more efficient utilization of the overall processing power of the system. Still further, the fact that personal computer 2 has the ability to implement FieldBus conttol routines, the FieldBus routines are further distributed between the local conttoller 4 and the personal computer 2. In this manner, the system allows personal computer 2 to implement one or all of the FieldBus routines for a particular control algorithm.

Still further, the system allows for the implementation of FieldBus controls to a non-FieldBus device connected directly to the ethernet 3 through use of the FieldBus conttol routines stored on personal computer 2 in the same manner that FieldBus routines are implemented on non-FieldBus device 12 through use on the FieldBus routines stored on local conttoller 4.

A process conttol environment 100 is shown in FIGURE IC and illustrates a conttol environment for implementing a digital conttol system, process conttoller or the like. The process conttol environment 100 includes an operator workstation 102, a laboratory workstation 104, and an engineering workstation 106 electrically interconnected by a local area network ("LAN") 108 for transferring and receiving data and conttol signals among the various workstations and a plurality of controller/multiplexers 110. The workstations 102, 104, 106 are shown connected by the LAN 108 to a plurality of the controller/multiplexers 110 that electrically interface between the workstations and a plurality of processes 112. In multiple various embodiments, the LAN 108 includes a single workstation connected directly to a controller/multiplexer 110 or alternatively includes a plurality of workstations, for example three workstations 102, 104, 106, and many controller/multiplexers 110 depending upon the purposes and requirements of the process control environment 100. In some embodiments, a single process controller/multiplexer 110 controls several different processes 112 or alternatively controls a portion of a single process.

In the process conttol environment 100, a process conttol sttategy is developed by creating a software conttol solution on the engineering workstation 106, for example, and transferring the solution via the LAN 108 to the operator workstation 102, lab workstation 104, and to controller/multiplexer 110 for execution. The operator workstation 102 and lab workstation 104 supply interface displays to the control/monitor sttategy implemented in the controller/multiplexer 110 and communicates to one or more of the controller/multiplexers 110 to view the processes 112 and change conttol attribute values according to the requirements of the designed solution. The processes 112 are formed from one or more field devices, which may be smart field devices or conventional (non-smart) field devices. The process 112 is illustratively depicted as two Fieldbus devices 132, a HART (highway addressable remote transducer) device 134 and a conventional field device 136.

In addition, the operator workstation 102 and lab workstation 104 communicate visual and audio feedback to the operator regarding the status and conditions of the controlled processes 112. The engineering workstation 106 includes a centtal processing unit (CPU) 116 and a display and input output or user-interface device 118 such as a keyboard, light pen and the like. The CPU 116 typically includes a dedicated memory 117. The dedicated memory 117 includes a digital conttol system program (not shown) that executes on the CPU 116 to implement conttol operations and functions of the process control environment 100 shown in FIGURE IC. The operator workstation 102, the lab workstation 104 and other workstations (not shown) within the process control environment 100 include at least one central processing unit (not shown) which is electrically connected to a display (not shown) and a user-interface device (not shown) to allow interaction between a user and the CPU. In one embodiment, the process conttol environment 100 includes workstations implemented using a Motorola 68040 processor and a Motorola 68360 communications processor running in companion mode with the 68040 with primary and secondary ethernet ports driven by the 68360 processor (SCC1 and SCC3 respectively).

The process conttol environment 100 also includes a template generator 124 and a conttol template library 123 which, in combination, form a control template system 120. A conttol template is defined as the grouping of attribute functions that are used to conttol a process and the methodology used for a particular process conttol function, the conttol attributes, variables, inputs, and outputs for the particular function and the graphical views of the function as needed such as an engineer view and an operator view.

The control template system 120 includes the control template library 123 that communicates with the template generator 124. The conttol template library 123 contains data representing sets of predefined or existing conttol template functions for use in process conttol programs. The control template functions are the templates that generally come with the system from the system designer to the user. The template generator 124 is an interface that advantageously allows a user to create new conttol template functions or modify existing conttol template functions. The created and modified template functions are selectively stored in the conttol template library 123.

The template generator 124 includes an attributes and methods language generator 126 and a graphics generator 128. The attributes and methods language generator 126 supplies display screens that allow the user to define a plurality of attribute functions associated with the creation of a new conttol template function or modification of a particular existing conttol template function, such as inputs, outputs, and other attributes, as well as providing display screens for enabling the user to select methods or programs that perform the new or modified function for the particular conttol template. The graphics generator 128 furnishes a user capability to design graphical views to be associated with particular conttol templates. A user utilizes the data stored by the attributes and methods language generator 126 and the graphics generator 128 to completely define the attributes, methods, and graphical views for a control template. The data representing the created conttol template function is generally stored in the conttol template library 123 and is subsequently available for selection and usage by an engineer for the design of process conttol solutions.

The process conttol environment 100 is implemented using an object-oriented framework. An object-oriented framework uses object-oriented concepts such as class hierarchies, object states and object behavior. These concepts, which are briefly discussed below, are well known in the art. Additionally, an object-oriented framework may be written using object-oriented programming languages, such as the C++ programming language, which are well-known in the art, or may be written, as is the case with the preferred embodiment, using a non-object programming language such as C and implementing an object-oriented framework in that language.

The building block of an object-oriented framework is an object. An object is defined by a state and a behavior. The state of an object is set forth by fields of the object. The behavior of an object is set forth by methods of the object. Each object is an instance of a class, which provides a template for the object. A class defines zero or more fields and zero or more methods.

Fields are data structures which contain information defining a portion of the state of an object. Objects which are instances of the same class have the same fields. However, the particular information contained within the fields of the objects can vary from object to object. Each field can contain information that is direct, such as an integer value, or indirect, such as a reference to another object.

A method is a collection of computer instructions which can be executed in CPU 116 by computer system software. The instructions of a method are executed, i.e., the method is performed, when software requests that the object for which the method is defined perform the method. A method can be performed by any object that is a member of the class that includes the method. The particular object performing the method is the responder or the responding object. When performing the method, the responder consumes one or more arguments, i.e., input data, and produces zero or one result, i.e., an object returned as output data. The methods for a particular object define the behavior of that object.

Classes of an object-oriented framework are organized in a class hierarchy. In a class hierarchy, a class inherits the fields and methods which are defined by the superclasses of that class. Additionally, the fields and methods defined by a class are inherited by any subclasses of the class. I.e., an instance of a subclass includes the fields defined by the superclass and can perform the methods defined by the superclass. Accordingly, when a method of an object is called, the method that is accessed may be defined in the class of which the object is a member or in any one of the superclasses of the class of which the object is a member. When a method of an object is called, process control environment 100 selects the method to run by examining the class of the object and, if necessary, any superclasses of the object.

A subclass may override or supersede a method definition which is inherited from a superclass to enhance or change the behavior of the subclass. However, a subclass may not supersede the signature of the method. The signature of a method includes the method's identifier, the number and type of arguments, whether a result is returned, and, if so, the type of the result. The subclass supersedes an inherited method definition by redefining the computer instructions which are carried out in performance of the method.

Classes which are capable of having instances are concrete classes. Classes which cannot have instances are abstract classes. Abstract classes may define fields and methods which are inherited by subclasses of the abstract classes. The subclasses of an abstract class may be other abstract classes; however, ultimately, within the class hierarchy, the subclasses are concrete classes.

All classes defined in the disclosed prefeπed embodiment, except for mix-in classes which are described below, are subclasses of a class, Object. Thus, each class that is described herein and which is not a mix-in class inherits the methods and fields of class Object.

The process control environment 100 exists in a configuration model or configuration implementation 210 and a run-time model or run-time implementation 220 shown in FIGURE 2. In the configuration implementation 210, the component devices, objects, interconnections and interrelationships within the process conttol environment 100 are defined. In the run-time implementation 220, operations of the various component devices, objects, interconnections and interrelationships are performed. The configuration implementation 210 and the run-time implementation 220 are interconnected by downloading. The download language creates system objects according to definitions supplied by a user and creates instances from the supplied definitions. Specifically, a completely configured Device Table relating to each device is downloaded to all Workstations on startup and when the Device Table is changed. For controller/ multiplexers 110, a downloaded Device Table only includes data for devices for which the controller/ multiplexer 110 is to initiate communications based on remote module data configured and used in the specific controller/ multiplexer 110. The Device Table is downloaded to the controller/ multiplexer 110 when other configuration data is downloaded. In addition to downloading definitions, the download language also uploads instances and instance values. The configuration implementation 210 is activated to execute in the run-time implementation 220 using an installation procedure. Also, network communications parameters are downloaded to each device when configuration data are downloaded and when a value is changed.

The process conttol environment 100 includes multiple subsystems with several of the subsystems having both a configuration and a run-time implementation. For example, a process graphic subsystem 230 supplies user-defined views and operator interfacing to the architecture of the process control environment 100. The process graphic subsystem 230 has a process graphic editor 232, a part of the configuration implementation 210, and a process graphic viewer 234, a portion of the run-time implementation 220. The process graphic editor 232 is connected to the process graphic viewer 234 by an intersubsystem interface 236 in the download language. The process conttol environment 100 also includes a control subsystem 240 which configures and installs conttol modules and equipment modules in a definition and module editor 242 and which executes the conttol modules and the equipment modules in a run-time controller 244. The definition and module editor 242 operates within the configuration implementation 210 and the run-time conttoller 244 operates within the run-time implementation 220 to supply continuous and sequencing conttol functions. The definition and module editor 242 is connected to the run-time controller 244 by an intersubsystem interface 246 in the download language. The multiple subsystems are interconnected by a subsystem interface 250.

The configuration implementation 210 and the run-time implementation 220 interface to a master database 260 to support access to common data structures. Various local (non-master) databases 262 interface to the master database 260, for example, to ttansfer configuration data from the master database 260 to the local databases 262 as directed by a user. Part of the master database 260 is a persistent database 270. The persistent database 270 is an object which transcends time so that the database continues to exist after the creator of the database no longer exists and transcends space so that the database is removable to an address space that is different from the address space at which the database was created. The entire configuration implementation 210 is stored in the persistent database 270.

The master database 260 and local databases 262 are accessible so that documentation of configurations, statistics and diagnostics are available for documentation purposes.

The run-time implementation 220 interfaces to the persistent database 270 and to local databases 262 to access data structures formed by the configuration implementation 210. In particular, the run-time implementation 220 fetches selected equipment modules, displays and the like from the local databases 262 and the persistent database 270. The run-time implementation 220 interfaces to other subsystems to install definitions, thereby installing objects that are used to create instances, when the definitions do not yet exist, instantiating run-time instances, and transferring information from various source to destination objects. Device Tables are elements of the configuration database that are local to devices and, in combination, define part of the configuration implementation 210. A Device Table contains information regarding a device in the process control environment 100. Information items in a Device Table include a device ID, a device name, a device type, a PCN network number, an ACN segment number, a simplex/ redundant communication flag, a conttoller MAC address, a comment field, a primary internet protocol (IP) address, a primary subnet mask, a secondary IP address and a secondary subnet mask.

Referring to FIGURE 3, a block diagram illusttates a user interface 300 for usage with both the configuration and run-time models of the process conttol environment 100. Part of the user interface 300 is the Explorer™ 310, an interfacing program defined under the Windows NT™ operating system which features a device-based configuration approach. Another part of the user interface 300 is a module definition editor 320 for interfacing using a control-based configuration approach.

The Explorer™ 310 is operated by a user to select, construct and operate a configuration. In addition, the Explorer™ 310 supplies an initial state for navigating across various tools and processors in a network. A user controls the Explorer™ 310 to access libraries, areas, process control equipment and security operations. FIGURE 3 illusttates the relationship between various tools that may be accessed by a task operating within the process conttol environment 100 and the relationship between components of the process conttol environment 100 such as libraries, areas, process conttol equipment and security. For example, when a user selects a "show tags" function from within an area, a "tag list builder" is displayed, showing a list of conttol and I/O flags. From the tag list builder, the user can use an "add tag" function to add a module to a list, thereby invoking a "module editor".

Referring to FIGURE 4, a schematic block diagram illustrates a hierarchical relationship among system objects of a configuration model 400. The configuration model 400 includes many configuration aspects including conttol, I/O, process graphics, process equipment, alarms, history and events. The configuration model 400 also includes a device description and network topology layout.

The configuration model hierarchy 400 is defined for usage by a particular set of users for visualizing system object relationships and locations and for communicating or navigating maintenance information among various system objects. For example, one configuration model hierarchy 400, specifically a physical plant hierarchy, is defined for usage by maintenance engineers and technicians for visualizing physical plant relationships and locations and for communicating or navigating maintenance information among various instruments and equipment in a physical plant. An embodiment of a configuration model hierarchy 400 that forms a physical plant hierarchy supports a subset of the SP88 physical equipment standard hierarchy and includes a configuration model site 410, one or more physical plant areas 420, equipment modules 430 and control modules 440.

The configuration model hierarchy 400 is defined for a single process site 410 which is divided into one or more named physical plant areas 420 that are defined within the configuration model hierarchy 400. The physical plant areas 420 optionally contain tagged modules, each of which is uniquely instantiated within the configuration model hierarchy 400. A physical plant area 420 optionally contains one or more equipment modules 430. An equipment module 430 optionally contains other equipment modules 430, control modules 440 and function blocks. An equipment module 430 includes and is controlled by a control template that is created according to one of a number of different graphical process conttol programming languages including continuous function block, ladder logic, or sequential function charting ("SFC"). The configuration model hierarchy 400 optionally contains one or more control modules 440. A conttol module 440 is contained in an object such as a physical plant area 420, an equipment module 430 or another conttol module 440. A conttol module 440 optionally contains objects such as other conttol modules 440 or function blocks. The conttol module 440 is thus a container class, having instances which are collections of other objects. The conttol module 444 is encapsulated so that all of the contents and the implementation of the methods of the conttol module are hidden.

Referring to FIGURE 5, a schematic block diagram shows a configuration architecture 500 that operates within the configuration model hierarchy 400 illustrated in FIGURE 4. The configuration architecture 500 includes a several objects and classes at multiple levels of absttaction. At an organizational level of abstraction 510, the configuration architecture 500 includes a site class 512 which contains "named" objects and classes within the configuration architecture 500. Named objects and classes are definitions, display components such as screens and graphics and other items. The named objects and classes include function blocks, user accounts, modules, plant areas, events, libraries and other site-wide information. Examples of named items are block definitions, equipment module definitions, conttol module definitions, plant area names and the like.

At a primitive level of abstraction 520, the configuration architecture 500 includes primitives that define the interfaces to functions within the configuration architecture 500, including hard-coded functions such as "+". The primitive level of abstraction 520 includes the classes of functions 522 and parameters 524. Functions 522 are operational functions at the lowest level of absttaction in the configuration architecture 500. Functions 522 are typically coded in the C or C++ languages. In one embodiment of the configuration architecture 500, the full set of implemented function blocks 522 are primitives. Objects and classes at the primitive level of abstraction 520 are defined throughout the site class 512. Parameters 524 are classes and objects at the lowest level of absttaction in the configuration architecture. Parameters 524 include integer numbers, real numbers, vectors, arrays and the like. Attribute values are mapped into parameters 524 for usage within a function block 522. In one embodiment, function blocks 522 at the primitive level of absttaction 520 include the function block primitives listed in TABLE I, as follows:

TABLE! Function Blocks

Action j Handles simple assignment statements using A defined

I expression capability.

ADD I Simple Add function with extensible inputs.

At a definition and usage level of abstraction 530, the configuration architecture 500 includes definitions 532 and usages. Definitions 532 and usages, in combination, define the algorithm and the interface for objects including function blocks, control modules, equipment modules, links and attributes. The definitions 532 define algorithms and interfaces for function blocks, modules, links and attributes. Usages are objects and classes at the definition and usage level of absttaction 530 that represent the usage of one definition within another.

At an instance level of absttaction 540, the configuration architecture 500 includes instances, which are "tagged" items within the configuration. Plant areas 542, modules 544, attributes 546, and PIO blocks 548 are tagged instances. Instances are defined according to definitions 532. A plant area 542 represents a geographical or logical segmentation of a process site class 512. All objects and classes at the instance level of absttaction 540 are defined throughout the plant area level so that all module instances have a 0 or 1 association with a plant area 542. To be installed in a run-time system, the module instances must have a 1 association, meaning that the module is viewed as being "contained by" or "scoped" in this context of a plant area. A module instance 544 is an installable object that is associated to a specific object of plant equipment. An attribute instance 546 is a visible parameter in a module instance 544, a plant area instance 542 or other device. An attribute instance 546 may be used for an input signal, an output signal, data storage or the like.

At a device level of absttaction 550, the configuration architecture 500 includes devices 552 such as controllers, smart devices and consoles, and input/output devices (10) 560 such as a PIO block, and the like, which represent physical process conttol equipment in the physical plant. A process input/output (PIO) block is an abstraction that represents various high density and low density conventional input/output devices including Hart, FieldBus and other input and output devices that are interfaced into the configuration architecture 500. High or low density relates to the number of channels on an I/O card. For example, 8 channels are typical on a low density card while a high density card may have 32 channels. Devices 552 are process conttol equipment in the configuration architecture 500 and include objects such as conttollers, input/output devices, consoles and the like. Input/output devices (IO) 560 are the physical process input and output devices in the configuration architecture 500.

A smart device is a field device that is implemented to transmit and receive digital data pertaining to a device, including data relating to device calibration, configuration, diagnostics and maintenance. Typically, the smart device is also adapted to transmit a standard analog signal that is indicative of various information including. for example, a process value measured by a field device. Examples of smart field devices include field devices which follow a HART (highway addressable remote ttansducer) protocol, a Fieldbus protocol, a Modbus protocol and a device net protocol.

Various hierarchical relationships among system objects are implemented to facilitate navigation through the process control environment 100 shown in FIGURE IC by different users and to accomplish different tasks. Four different hierarchical relationships are defined including control, conttol system, operations and physical plant hierarchies. A specific system object may be implemented in multiple hierarchical systems.

The control hierarchy is a subset of a standard SP88 hierarchy and has system objects including site, physical area, equipment module, conttol module and control element objects. The conttol hierarchy is used to organize conttol operations and to define the scope of named objects. A user interacts with the conttol hierarchy on the basis of a site instance, equipment module definitions, conttol module definitions, a plant area instance, equipment module instances, control module instances, display module instances, and process I/O module/block instances, having signal tags.

The conttol system hierarchy includes operator/configuration stations, host computers, conttollers, I/O devices, smart devices, gateways and the like, which are associated using various network standards including area conttol network (ACN), process control network (PCN) and other I/O network standards. In one embodiment, the ACN hardware includes standard 10-base-T ethernet communication ports and a workstation contains standard Ethernet 10-base-T interface cards and software drivers. A user interacts with the conttol system hierarchy on the basis of a defined site instance, a network definition, a defined network instance, devices, and subsystems such as files, cards, channels, conttollers, operation stations, and Fieldbus segments.

The area conttol network (ACN) includes communication functionality at two levels, a remote object communications (ROC) level and a low level communications level. ROC level controls the interface between the Programmed applications and the ACN communications system. The low level communications support the interface with the TCP/EP sockets and the actual transmission of messages.

Remote Object Communications (ROC) are system operations supporting communication of objects in the process conttol environment 100 shown in FIGURE IC and particularly supporting communication between objects whether the objects reside in the same device or in remote devices. The ROC communication level supports communications message services including request/response, unsolicited reporting, event/alarm reporting and broadcast message service.

Request Response is a service by which applications send messages to a remote device and receive a response from the device. Unsolicited Reporting is a service for periodically sending updated data to a remote device. Unchanged data is not reported. Event Alarm Reporting is a guaranteed delivery message service which is used for the transmission of events, alarms and other vital information for delivery to a remote device. The broadcast message service is used to send messages to all Program application devices on the communications network. The ROC level also sets communications policies for the communications subsystem. This means that it is responsible for managing what message get sent and when as well as how incoming messages are processed. Commumcations flow conttol will also be the responsibility of the ROC portion.

Low level communications support is included for device connection management, ACN redundancy and communications systems diagnostics. Device connection management establishes a communications connection between two devices and manages the transmission of messages between the two devices. ACN Redundancy handles the detection of communications link failures, controls the switch from one link to another and tracks the status of communication links between a host device and connected remote devices. Communications subsystem diagnostics tracks communication integrity and statistical information, responds to requests for communications diagnostic data.

Device connection management in an ACN communications system supports both UDP and TCP type device connections. UDP connections are used for normal real time data transfers between devices. TCP connections are used for special applications using a streaming protocol such as file transfers, device flash downloads, and the like. Communications between devices is managed by a Device Connection Object. The Device Connection Object transmits data and maintains the status of the communications links between two communicating devices.

All normal device connection message traffic is directed through a single UDP communications port. A Device Connection Object starts the communications system by creating the communication socket associated with this UDP port as well as creating the queues needed for management of the device connection message traffic. The Device Connection Object receives all incoming messages on a Device Connection communications socket and routes messages to the proper device connection instance for processing. The Device Connection Object handles timing functions of device connections, including notifying device connection instances when messages time out waiting to be acknowledged, when communications link checks are due and when device connection resyncs have timed out.

UDP type communications are used for the transfer of real-time data among devices. The remote object communications (ROC) subsystem passes messages to a UDP Device Connection for transmission to a destination device. A pool of message buffers is created on startup of each device. The message pool is used for all data transferred between devices, preventing the communications subsystem from exhausting memory and ensuring that no other task exhausts memory, thereby preventing the communication subsystem from running. Communication flow conttol is implemented in the Device Connection Object. If the number of message buffers in the communications buffer pool reaches a predefined low level, all remote devices are inhibited from sending messages until the low buffer problem is resolved in the affected device preventing loss of messages.

TCP-type commumcations are used for applications using a streaming-type protocol such as file transfers and device flash downloads. TCP-type connections are temporary connections established for the duration of the applications needs and terminated once the application has completed a communications task. For reasons of interoperability, compatibility, and availability, a TCP/EP protocol stack is employed. The TCP/IP stack supplies a connection-oriented, byte stream protocol (TCP) and a connectionless, message oriented protocol (UDP). The device connection supports request/response messages, unsolicited data, and event and alarm data between devices. The communication system maintains the device connection through one of two available communications links in the event of a single communications failure, typically a cable fault. Detection of a fault and switch to an alternate communications path transpires in a short, deterministic time span which is less than one second.

The operations hierarchy is defined for a particular set of users, specifically operators and maintenance engineers, generally for the purpose of accessing displays, reports, and other informational items. A user interacts with the operations hierarchy on the basis of a site instance, User Group definitions, a plant area instance, equipment module instances, conttol module instances, display instances, and report instances. The physical plant hierarchy is defined for a particular set of users, specifically maintenance engineers and technicians, typically for the purpose of determining physical relationships among objects and navigating maintenance information about plant instruments and equipment. A user interacts with the physical plant hierarchy on the basis of a site instance, a maintenance area instance, a plant area instance, room instances, cabinet instances, node/device instances and display instances.

The system objects that are implemented in the multiple hierarchical systems are arranged into a plurality of subsystems including conttol, process I/O, conttol system hardware, redundancy management, event/alarm management, history services, process graphics, diagnostics presentation, user environment, management organization and field management system (FMS) subsystems. The conttol subsystem includes routines for configuring, installing and executing control modules and equipment modules. The process I/O subsystem is a uniform interface to devices including HART, Fieldbus, conventional I O and other input/output systems. The conttol system hardware subsystem defines a conttol system topology, devices within the topology and capabilities and functions of the devices. The control system hardware subsystem also includes objects and data structures for accessing device level information indicative of status and diagnostics.

The redundancy management subsystem establishes a redundant context between primary and secondary control applications and manages switching in context between the primary and secondary conttol applications. The redundancy management subsystem also maintains and monitors redundant context diagnostic information including state information and data latency information. Network redundancy is accomplished using two separate Ethernet communications links or networks. The primary communication link is the preferred communications path. The secondary link is only used if the primary has failed. Communications switchovers are performed on a per device basis. For example, if device A is communicating with devices B and C and the primary link to device C fails, device A continues to communicate with device B on the primary link but switches to the secondary link to communicate with device C. Each Ethernet link is a separate, dedicated network having a dedicated set of EP addresses and a subnet mask.

The device connection object manages redundant communications including controlling when to switch to the secondary link and when to switch back to the primary link. Each device in the process control system tracks the communication status of all current links to remote devices by periodically sending link test messages when no other communications is occurring, to check the status of the communications links to each device. Redundancy switchovers are performed on a device connection basis.

The event alarm management subsystem configures, monitors, and supplies notification of significant system states, acknowledgments and priority calculations. The history services subsystem stores and retrieves process and event information. The process graphics subsystem supplies user-defined views for display and operator interfacing onto the defined system architecture. The diagnostics presentation subsystem furnishes displays of diagnostic information, typically at the request of a user. The user environment subsystem supplies a user interface, allowing a user to enter commands to control operation of the process conttol environment 100 shown in FIGURE IC. The management organization subsystem sets an organizational structure of the process conttol environment 100 including specification of site, area, primitives, access to user libraries, and location of defined objects and instances. The FMS supplies user interfaces, views, and organization structure for the configuration, installation and monitoring of HART and Fieldbus devices.

A Fieldbus device implements localized conttol of a process within the process, in contrast to a longer-used and more conventional approach of controlling device functions from a main or centralized digital conttol system. A Fieldbus device achieves localized conttol by including small, localized controller/ multiplexers 110 which are closely associated with field devices within the Fieldbus device. The small, localized controllers of a Fieldbus implement standardized conttol functions or control blocks which operate on the field devices within the Fieldbus device and which also operate on other smart field devices that are connected to the Fieldbus device.

Thus, the process conttol environment 100 implements smart field device standards, such as the Fieldbus HI standard, Profibus standard, CAN standard and other bus-based architecture standards so that communications and conttol among devices, particularly Fieldbus devices, are performed so that Fieldbus- type conttol operations are transparent to a user.

The process conttol environment 100 allows attachment to a substantially unlimited number and type of field devices including smart devices, such as Fieldbus and HART devices, and conventional non- smart devices. Conttol and communication operations of the various numbers and types of devices are advantageously performed simultaneously and in parallel.

The process conttol environment 100 implements and executes a standard set of function blocks or conttol functions defined by a standard Fieldbus protocol, such as the Fieldbus HI standard, so that smart- type conttol is achieved with respect to non-smart-type devices, such as a HART device 134 and a conventional device 136. In addition, the process control environment 100 enables Smart devices to implement the standard set of function blocks and conttol functions. Advantageously, the process control environment 100 implements an overall sttategy as if all connected devices are Smart devices. This implementation is achieved, in part, by the usage of a function block as a fundamental building block for conttol structures. These function blocks are defined to create control structures for all types of devices. Usage of function blocks as fundamental building blocks is described in FIGURES 6, 7, 8 and 9.

The process control environment 100 implements an overall, user-developed conttol sttategy through the definition of function blocks and control modules by downloading or installing specific portions of the conttol sttategy into smart devices and non-smart devices. Thereafter, the smart devices automatically perform the downloaded portions of the overall sttategy independently of other conttol system operations. For example, the portions of the conttol strategy downloaded or installed into the devices operate independently of and in parallel with the control operations of the controller/ multiplexers 110 and the workstations, while other conttol operations manage the smart devices and implement other portions of the conttol strategy. In effect, the process conttol environment 100 implements a conttol sttategy using the controller/ multiplexers 110 within the smart devices.

An example of a block diagram defining a function block of the functions 522 shown in FIGURE 5 is illustrated in FIGURE 6. Specifically, FIGURE 6 depicts an "elemental" function block definition 600 which is defined to contain only primitive objects. The elemental function block definition 600 defines a sum function and includes a "+" primitive 610, a first input attribute 612 which is a first parameter 614 applied to the primitive 610, and a second input attribute 622 which is a second parameter 624 applied to the primitive 610. The primitive 610 produces a result that is supplied as an output attribute 630. In this example, the elemental function block definition 600 is a block definition that is created and named SUM.

A second example of a block diagram defining a function block of the functions 522 shown in FIGURE 5 is illustrated in FIGURE 7. Specifically, FIGURE 7 depicts a "composite" function block definition 700 which is defined to contain one or more elemental function blocks 600 and, optionally, one or more primitive objects. The composite ftmction block definition 700 defines a composite sum function and includes a first SUM elemental function block 710 and a second SUM elemental function block 712, each of which is the same as the SUM elemental function block 600 illustrated in FIGURE 6. The composite function block 700 has a first input attribute 720 and a second input attribute 722 which are respective first and second parameters 724 and 726 applied to the first SUM elemental function block 710. The first elemental function block 710 produces a result that is applied to the second SUM elemental function block 712 as a first parameter 730. The composite function block 700 has a third input attribute 728 that is a second parameter 732 applied to the second SUM elemental function block 712. The second SUM elemental function block 712 produces a result that is supplied as an output attribute 734. In this example, the composite function block definition 700 is a block definition that is created and named SUM3.

An example of a block diagram defining a conttol module of the conttol modules 440 shown in

FIGURE 4 is illustrated in FIGURE 8. Specifically, FIGURE 8 depicts a conttol module definition 800 which is defined and contains various input attributes 810, elemental function blocks 820, a first SUM3 composite function block 830 and a second SUM3 composite function block 832. The exemplary conttol module 440 includes five input attributes 810 which are connected to five respective elemental function blocks 820, three of which are parameters applied to the first SUM3 composite function block 830. The first SUM3 composite function block 830 produces a result that is supplied as a parameter to the second SUM3 composite function block 832 in combination with parameters supplied by the remaining two elemental function blocks 820. The second SUM3 composite function block 832 produces a result that is supplied as an output attribute 840. In this example, the conttol module 800 is a control module definition that is created and named CM1. Examples of block diagrams defining a module instance of the module instances 544 shown in FIGURE 5, specifically a control module instance, are shown in FIGURE 9. Conttol module instances 910 and 920 are created in accordance with the CM1 control module definition so that each conttol module instance 910 and 920 includes five input attributes 912 and 922, respectively, that correspond to the five input attributes 810 shown in FIGURE 8. Each control module instance 910 and 920 also includes one output attribute 914 and 924, respectively, that correspond to the output attribute 840 shown in FIGURE 8. In this example, the conttol module instances 910 and 920 are control module instances that are created and tagged CALCl and CALC2, respectively.

Using a definition editor, a system user creates and names definitions, such as the SUM elemental function block definition, the SUM3 composite function block definition and the CM1 conttol module definition. Then, using a module editor, the system user creates and tags instances, such as the CALCl and CALC2 conttol module instances.

Referring to FIGURE 10, a flow chart shows an example of conttol module execution at run-time. A run-time program includes a scheduler routine. Scheduler routines are well-known in the computing arts. The scheduler routine requests execution 1010 of a composite conttol module, for example the composite control module 440 with tag CM1 shown in FIGURE 8. The CM1 composite conttol module 440 initiates ttansfer 1012 of the input attributes 820, causing any associated links, or attribute associations, to transfer 1014. A database definition typically refers to "associations" while a runtime definition relates to "links". In steps 1016 through 1056 the CM1 composite conttol module 440 requests each elemental function block 820, first SUM3 composite function block 830 and second SUM3 composite block 832 to execute in turn.

Specifically, in step 1016 the CM1 composite conttol module 440 requests each elemental function block 820 to execute. The elemental function blocks 820 initiate ttansfer 1018 of input attributes, for example first input attribute 612 shown in FIGURE 6. The input attributes of the elemental function blocks 820 request 1020 loading of values from the links ttansfeπed in step 1014. The links copy 1022 values from source attributes to destination attributes. The elemental function blocks 820 execute block algorithms 1024. Upon completion of block algorithm execution, the elemental function blocks 820 initiate ttansfer of output attributes 1026, for example output attribute 630 shown in FIGURE 6.

In step 1028 the CM1 composite conttol module 440 requests first SUM3 composite function block 830 to execute. First SUM3 composite function block 830 initiates ttansfer 1030 of input attributes, for example input attributes 722, 724 and 726 shown in FIGURE 7, from the elemental function blocks 820. In step 1032, first SUM3 composite function block 830 requests internal function blocks, for example, the first SUM elemental function block 710 and the second SUM elemental function block 712 shown in FIGURE 7, to execute in turn. First SUM elemental function block 710 reads input attributes, executes a block algorithm and sets an output attribute in step 1034. Second SUM elemental function block 712 reads input attributes, executes a block algorithm and sets an output attribute in step 1036. First SUM3 composite function block 830 initiates ttansfer of output attributes in step 1038. The output attribute of first SUM3 composite function block 830 requests an associated link to copy the value from the output attribute in step 1040.

In step 1042 the CM1 composite conttol module 440 requests second SUM3 composite function block 832 to execute. Second SUM3 composite function block 832 initiates ttansfer 1044 of input attributes from the links connected to the first SUM3 composite function block 830 output attributes. In step 1046, second SUM3 composite function block 832 requests internal function blocks, for example, the first SUM elemental function block 710 and the second SUM elemental function block 712 shown in FIGURE 7, to execute in turn. First SUM elemental function block 710 reads input attributes, executes a block algorithm and sets an output attribute in step 1048. Second SUM elemental function block 712 reads input attributes, executes a block algorithm and sets an output attribute in step 1050. Second SUM3 composite function block 832 initiates ttansfer of output attributes in step 1052. The output attribute of second SUM3 composite function block 832 requests an associated link to copy the value from the output attribute in step 1054.

In step 1056 the CM1 composite conttol module 440 initiates ttansfer of output attributes and output attribute 840 requests a link from second SUM3 composite function block 832 to copy the value of the second SUM3 composite function block 832 output attributes. In some embodiments, output function blocks push output values to a user-configured PIO block attribute (not shown). Thus, PIO attributes are "pulled" by function blocks while output function blocks push output values to PIO Block attributes. Similarly, input function blocks pull input attribute values from PIO Block attributes.

A user defines a module conttol sttategy by specifying function blocks that make up conttol modules and determine the control sttategy. The user modifies or debugs a module control sttategy by adding, modifying and deleting function blocks, configuring parameters associated with the function blocks and creating a view to new attributes.

By defining function blocks and conttol modules, a user-defined control sttategy, application program or diagnostic program is represented as a set of layers of interconnected control objects identified as modules. A layer of the conttol sttategy includes a set of modules which are interconnected in a user- specified manner. A module typically includes an algorithm for performing a specific function and display components which are used to display information to a user. A module is optionally represented to include a set of input and output connections for connecting to other modules. A module may be considered to be a "black box" which performs a specified function and is connected to other modules via specified input and output connections.

Referring to FIGURE 11, a display screen serves as a flow chart which shows an example of a module or application program LOOPSIM 1060 at a highest layer of a conttol structure. The illusttated layer of the LOOPSIM 1060 application program includes an input attribute (AIN) module 1062 called AH, a deadtime module 1064, a proportional, integral, differential (PED) control module 1066, an output attribute (AOUT) module 1068 and a simulate module 1070. Each of the illustrative modules includes named input __3f._

connections and output connections which are connected to the other modules via lines. The set of modules, the input connections and the output connections of the set of modules, and the interconnections between modules define the operation of the LOOPSIM 1060 application.

At a lowest level, a module is a set of interconnected function blocks. At higher levels, a module is a set of interconnected submodules which, in turn, may include a further set of submodules. For example, the PED conttol module 1066 is typically a set of interconnected submodules which perform the different functions included in a PED functionality. The input and output connections of the PED module 1066 are an input connection and an output connection of one or more of the submodules within a next lower layer of the PED module 1066. The submodules in the PED module 1066 optionally include other input and output connections sufficient to define the interconnections between the submodules.

An application, a module or a submodule, at any module level, is optionally modified by a user to perform a slightly different function or to perform the same function in a different manner. Thus, a user optionally modifies the module, thereby modifying the conttol structure, in a desired manner. Specifically, a user optionally adds input and output connections to modules and extends the input and output connections of a module to a higher level module so customize modules for various applications. For example, a user optionally adds a new input connection or output connection to the PED module 1066 to the "edge" of the PED module 1066 which makes the input connection and output connection appear as input and output connections to the PID module 1066.

The process conttol environment facilitates the definition and modification of the conttol structure by furnishing editing operations in a plurality of conttol languages including EEC-1131 standard languages such as Field Blocks, Sequential Function Charts (SFC), Ladder Logic and Structured Text. Accordingly, different types of users, from different conttol backgrounds use the different languages to write different modules for implementing the same or different applications.

Conttol modules are specified to have several advantageous characteristics. Some conttol modules allow direct access to attributes. For example, some attributes, called "heavy" attributes, support direct

(maximum performance) communications. Direct communications are advantageously used for connecting function blocks and Control Modules, supporting event/alarm detection, and high performance trending, for example. Some attributes are created automatically upon definition of a conttol module with a user having the option to promote or force a parameter to be exposed as an attribute of a Conttol Module. Other parameters are made accessible through a module, such as a Control Module, an Equipment Module, a PIO Block, or a Device, which contains the parameter but direct communications performance of the attributes does not warrant the overhead incuπed in supplying this performance. These parameters are advantageously accessed to supply information relating to conttol system tuning, debugging and maintenance. In some embodiments, these parameters are accessed by a general purpose parameter browser applications, which use services provided by tagged containers to reveal attributes, invokeable services, and subcomponents within the containers. Referring to FIGURE 12, a block diagram illusttates an object-oriented method for installing a process I/O attribute block into a PIO device through the operation ofthe conttol subsystem. A block of defined objects 1110 includes a site object 1112, a conttoller device 1114, a controller I/O subsystem 1116, a PIO interface device 1118 and a PIO device 1120. Prior to installation ofthe PIO device, the controller I/O subsystem 1116 is previously created. The PIO device 1120 is also previously created, either by installation or downloading. The block of defined objects 1110 directs a detail pointer 1122 to a list of block definitions 1124 to specify a particular type of object to be created by a create pointer 1126 directing the operation of a create block 1128. The block definitions 1124 includes a PIO input attributes (AIN) block definition either as hardwired or by previous installation. Attributes ofthe specified object are set by a user through the operation ofan editor 1130. Prior to installation ofthe PIO device, an input attribute (AIN) block 1132 does not exist.

Prior to installing the AIN block 1132, a user creates the PIO device 1120 then sets up initial values for AEN block attributes using the editor 1130. The user also sets a period for view parameter acquisition. The AEN block 1132 is saved and then installed.

Referring to FIGURE 13, a block diagram illusttates an object-oriented method for linking a

Conttol Module input attribute to a process I/O attribute. Prior to linking ofthe control module input attribute to the PIO attribute, the PIO block AIN 1220 is previously installed and the control module 1210 is also installed. The user specifies that a PIOEN attribute 1212 ofthe conttol module 1210 is connected to an attribute input process variable PV 1214 and requests that a link be made. A link 1216 is made as the control module finds the PIOIN attribute and returns a corresponding attribute index, locates PIO AIN in a plant area, find the process variable PV attribute and returns a corresponding attribute index, instructs the run-time linker 1216 to create a link with a source at the process variable (PV) 1214 and a destination at the PIOIN attribute 1212, creates the link and connects the link 1216. At end of a download , links are resolved by the linked objects.

Referring to FIGURE 14, a block diagram shows an object-oriented method for linking a conttol module output attribute (AOUT) 1312 attribute to a PIO output attribute (PIOAOUT) 1320. A conttol module 1310 is previously installed and the conttol module output attribute (AOUT) 1312 is installed within the conttol module 1310. The user specifies that the conttol module output attribute (AOUT) 1312 is connected to the a PIO output attribute (PIOAOUT) 1320. The link is made as the run-time implementation ofthe conttol module 1310 is sent a message to form the connection, the control module 1310 finds the AOUT attribute, requests location ofthe PIOAOUT attribute 1320, creates a link 1322 and connects the AOUT attribute 1312 and the PIOAOUT attribute 1320 to the link 1322.

Referring to FIGURE 15, a block diagram shows an object-oriented method for reading values of contained PIO attributes. A PIO block 1410 is previously installed and an output attribute (AOUT) 1412 is previously installed within the PIO block 1410. A user, for example an engineer, requests a detailed view of the block in which all attribute values are displayed. The detailed display includes one or more sets of display groups, also called view definitions, associated with the PIO block 1410. A proxy is previously established for the PIO Block 1410. A user requests detail for the output attribute (AOUT) 1412. Attribute names and values for the AOUT block are presented by an application program requesting a proxy client routine to access a view, an AOUT proxy client setting a return view definition and creating an attribute proxy object, and the application program requesting the AOUT proxy client to read out values for attributes named with granted privileges. The application program formats and displays the data. Display group parameters are part ofan I/O block definition and are, therefore, not configurable. Display groups are defined for attributes. Information is advantageously updated while a PIO block is not linked since display groups and view groups conttol updating of non-linked PIO attributes associated with a block.

The process control environment 100 shown in FIGURE IC implements an overall strategy as if all connected devices are Fieldbus devices not only by the usage of a function block as a fundamental building block for conttol structures, but also by implementing an input/output architecture that treats Fieldbus and nonFieldbus devices in the same manner. The fundamental character ofthe input/output arcMtecture is based on instrument signal tags (ISTs) that furnish user-configurable names for all I/O signals including Fieldbus and nonFieldbus I/O signals.

From the perspective of a user, an 1ST binds a user-defined name to a signal type, to a specific signal in the I/O subsystem, to a signal path including an attribute and to a set of signal property settings.

ISTs are not installed in the manner of other system objects. Instead, signal properties inherent to the 1ST tag are combined with I/O Port and I/O Device properties that are made available when an I O Card is installed. The combination of 1ST, I/O Port and I/O Device properties furnish information for creating a PIO function block in the run-time system. The signal path from ISTs is included in the script that defines I/O Function Blocks during installation of a module.

To communicate throughout the process conttol environment 100, an I/O type Function Block uses an I/O reference definition. An 1ST satisfies the specification for an I/O reference. Conventional I/O devices, such as MTL devices supplied by Measurement Technologies Limited ofthe United Kingdom, have an 1ST for each channel. Hart and Fieldbus I/O devices may include an 1ST for each distinct "I/O signal" on a Port or in a field Device. 1ST names have system-wide scope and share the name space of Modules, Devices, and Areas. In large systems, ISTs typically correspond to instrument signal names on instrumentation drawings. In small systems, formal instrument drawings may not exist so that no obvious 1ST names are inferred. Typically, ISTs are automatically generated as cards are configured based on a device hierarchy path representing a conttoller node, I/O subsystem, card and port so that arbitrary 1ST names are avoided. Typically most ISTs are created automatically when a new I/O card is defined. For multiple-signal I/O devices, an 1ST is automatically created for only a single "primary signal". In addition to automatic 1ST creation, a user may also create ISTs using an "Assign..." menu available from the Explorer Node/IOsubsys/Port/Device tree with a Port or Device selected or using a "New..." menu available from the Explorer 1ST tree.

ISTs have a "signal type" property to ensure compatibility between the I/O signal and the I/O Function Block(s) that accesses the I/O signal. Signal type is one of: AIN, AOUT, DEN, DOUT, PCIN, PCOUT. ISTs have a set of "signal-related" attributes specific to the signal type (e.g. EUO and EUlOO for a AIN, MOMENTARY or LATCHED for a DOUT, etc.). All signal sources with the same signal type have the same set of "signal attributes". All other properties ofthe I/O subsystem objects are held in card, port, or device attributes.

Fully configured ISTs have a fully qualified path to a corresponding signal in the I/O system, e.g. "CONl/IOl/S01/C01/FEELD_VAL". An 1ST may be created without a defined path defined so that module configuration may be completed before I/O structure details are fully defined. Modules with I/O Function Blocks using ISTs with no defined path may be configured and installed but the run-time system must deal appropriately with missing I/O paths of missing ISTs on I/O Function blocks. A signal source has no more than one 1ST. Attempts to configure more than one 1ST with the same path are rejected.

A user may delete an 1ST, thereby deleting associated signal properties and possibly leaving some unresolvable 1ST references in I/O Function Blocks. A deleted 1ST does not affect card/port/device properties with a normal display ofthe 1ST on the Port/Device in the Explorer tree indicating no associated 1ST.

I/O-interface Function Blocks have at least one IST-Reference property. An IST-Reference property is either left blank to indicate that the function block does not connect to a 1ST, or is designated with a valid 1ST name. An IST-Reference property in an I/O Function Block is compatible with exactly one 1ST signal type. For example, the IST-Reference in the Al Function Block has an 1ST with a signal type "AIN" only. Several I/O Function Blocks are compatible with the same 1ST signal type.

For compatibility with Fieldbus I/O Function Block definitions, Fieldbus I/O Function Blocks have attributes such as XD SCALE, OUT SCALE which overlap with some ofthe signal properties in ISTs. When a valid IST-Reference is made, the configured values of these overlapped Function Block attributes are ignored in the Run-time system and the coπesponding properties from the 1ST are used instead. An engineer configuring Fieldbus I/O Function Blocks uses an indication of ignored attributes when a 1ST reference is in place. Such an indication is typically presented on a display as grayed out and non-editable text with values copied from the 1ST. The I/O Function Block holds a private setting for the ignored attributes which are typically downloaded and promptly overridden. If the IST-Reference is removed, the setting for these attributes retains utility.

I/O Cards, Ports and Devices are incoφorated into a configuration by a user operating a user interface, either the Explorer™ or the Module Definition Editor. The channels on conventional I/O cards are called "ports" and treated as an I/O Port so that special case terminology for conventional I/O is avoided. The user interface also allows a user to delete I/O Cards, Ports or Devices. Multiple I/O Card types are supported including, for example, 8-chan MTL Al, 8-chan MTL AO, 8-chan MTL DI, 8-chan MTL DO, 4- chan MTL Thermocouple/RTD, 8-chan HART input, 8-chan HART output, and 4-chanSolenoid. Some I/O Card types have a combination of I/O Port types on the same I/O Card. Deletion of an I/O Card deletes all subordinate Ports. Deletion of an I/O Port deletes all subordinate Devices. Deletion of I/O Ports or I/O Devices does not delete related instrument signal tags (ISTs), but the path ofthe 1ST path to the associated I/O signal no longer is operable. If another I/O Port or I/O Device is created which has the same path, the 1ST automatically rebinds to the I/O Port or I/O Device, so long as the signal type is compatible.

A user can initiate the Install of an I/O subsystem, which installs or reinstalls all I/O Cards defined in the Subsystem. The user can initiate the Install of a single I/O Card, which installs the card properties and all properties for subordinate I/O Ports and I/O Devices.

The Explorer™ and the Module Definition Editor configure the I/O subsystem by accessing current signal values, status, and selected properties that are directly addressable as Attributes in the I/O subsystem. The user displays a graphic indicative ofthe current status of cards, ports, devices, and signal values and status by accessing the respective cards, ports, devices and signal values and status using device hierarchy attribute path addressing (for example, "CONl/IOl/C01/P01/FIELD_VAL").

I/O subsystem attributes are communicated using the physical device path (for example, CONl/IOl/COl/POl/DOl/FEELD VAL) for addressing in communications between devices. Communication of I/O subsystem attributes is advantageously used to transmit attributes from a controller/multiplexer 110 to a workstation 102, 104, 106 as shown in FIGURE IC for display and from a first to a second controller/multiplexer 110 for virtual I/O handling.

Referring to FIGURE 16, a block diagram illusttates an organization of information for an instrument signal tag (1ST). An system 1ST table 1510 contains information relating to an 1ST including path information and pointers to a system object. A first pointer 1512 designates a signal type which points to an attribute signal table 1520. A second pointer 1514 designates an entry in the attribute signal table 1520.

Accessing of information using device hierarchy attribute addressing advantageously allows system diagnostic displays to be designed and built for system integration checkout before Control Module work is complete. Device hierarchy attribute addressing also supports direct addressing of I/O signals from Modules, bypassing the use of I/O function blocks and avoiding I/O function block behavior. I/O Card, I/O Port and I/O Device identifiers are generally defined automatically according to slot position information and the like.

Referring to FIGURE 17, a flow chart illusttates a method for bootsttap loading a conttol system throughout a network in the process control environment 100, including the operations of assigning the controller/ multiplexers 110 to a set of EP Addresses, a node name and other startup information that is not stored in flash ROMs of a controller/ multiplexer 110. A process 1600 for assigning internet protocol (EP) Addresses to a Conttoller upon its initial bootup includes the step of associating a MAC address in a Boot server, a Windows NT™ workstation, with a controller/ multiplexer name 1610. The MAC address alone designates the controller/ multiplexer identity. In step 1612, the name ofthe controller/multiplexer is assigned an arbittary device ID, and an ACN link number and a PCN network number that are determined by the cable attached to the controller/ multiplexer. In step 1614, an EP address of a device is calculated from the device ID, the ACN link number and the PCN network number. In step 1616, a UDP datagram, which designates default primary and secondary EP addresses that are reserved for booting nodes and includes the controller/ multiplexer MAC address in the UDP user data, is broadcast to a special UDP reserved boot port using the default primary LP address for the source address on the primary interface. In step 1618, the boot server matches the MAC address with the assigned name and EP addresses, and broadcasts the assigned name and EP addresses with an echo ofthe MAC address to the UDP boot port. By broadcasting, the problem of doing any routing or ARP static entry manipulation is avoided. In step 1620, the controller/ multiplexer receives the datagram, checks the MAC address, and if the MAC address matches, sets the EP addresses and saves the node name and device ED. If the datagram is not received, the procedure is repeated using the secondary interface through the operation of branch step 1622. In step 1624, the controller/ multiplexer, using the new address, sends a message to the boot server saying indicating that the controller/ multiplexer is operational.

In step 1626, a user enters a Device Name, Device MAC Address, ACN Link Number and PCN Network Number. The device ED can be automatically assigned by configuration software. The communications subsystem calculates the devices three IP addresses from the configured ACN Link number, PCN Network Number and the assigned device ED. En step 1628, controller/ multiplexer or I/O card software is flash downloaded over the ACN network by passing messages and S-Record files between devices on the ACN.

Referring to FIGURE 18, an object communication diagram shows a method for creating a device connection for the active, originating side of a connection. An application program in either a workstation or a controller/ multiplexer requests access to an attribute which is contained in another device. A UDP communications connection to the other device is established by the communication services so that the attribute can be accessed. Creation of a device connection spans two separate application programs. The application program which initiates the connection by requesting data located in another device and the

Remote Object Communications (ROC) Services application program that actually sends the messages to the other device. If no connection exists when the ROC Services process is ready to send a message to a device, the ROC services create a connection to that device.

Prior to creating the device connection, a device to be connected has a valid Device Table containing the source device, is operating and includes an object RtDeviceConnection which monitors messages on the device connection port. After the device connection is created, a connection is established between the two devices and an RtDeviceConnection instance is created in the active device to handle the connection.

In step 1710, an application program sends a message getContainer to object RtSite which returns the object ID ofthe module found or created. In step 1712, object RtSite sends a Locate message to object RtPlantArea which locates the module and return its object ED. In step 1714, object RtSite sends a

GetDevice message to object RtDevice which returns the object ED ofthe device containing the module. In step 1716, assuming that a proxy for the remote device does not exist, object RtDevice sends a Create message to object RtDeviceProxy. In step 1718, object RtDeviceProxy creates an instance of object RtDeviceProxy using template RtNew. In step 1720, object RtDeviceProxy asks object RtDeviceConnection to GetDeviceConnectionlndex which returns the index ofthe device name in the device connection table managed by object RtDeviceConnection. In step 1722, object RtDeviceProxy registers the pointer to the RtDeviceProxy instance for the connected device by sending a RegisterPointer message to the object RtRegistry and returns the device proxy Object ED to object RtDevice. In step 1724, object RtPlantArea sends a Create message to object RtModuleProxyClient to create a proxy client for the remote module. In step 1726, object RtModuleProxyClient sends a Create message to object

RtModuleProxyServer to create a proxy server for the module in the remote device. In step 1728, object RtModuleProxyServer builds a create proxy server message and asks object RtRocReqRespService to SendRequest to the remote device. In step 1730, object RtRocReqRespService Appends the message to the Outbound Message Queue for the ROC Communications Services process to send to the remote device. In step 1732, object RtRocReqRespService in the ROC Comm Services process issues a RemoveFirst command to the Outbound Message Queue and gets the create proxy server message. In step 1734, the RtRocReqRespService sends the message by issuing a sendMsg command to the aRtDeviceProxy instance for the destination device. In step 1736, the aRtDeviceProxy instance issues a GetDeviceConnection command to RtDeviceConnection to get the Object ED for the RtDeviceConnection instance for the destination device. Assuming that a device connection does not already exist, in step 1738, object

RtDeviceConnection performs a createDeviceConnection. In step 1740, object RtDeviceConnection creates an instance of RtDeviceConnection using template RtNew. In step 1742, object RtDeviceConnection registers the pointer to the RtDeviceConnection instance by sending a RegisterPointer message to the object RtRegistry and returns the device connection Object ED to object RtDeviceConnection. In step 1744, object RtDeviceConnection sends a start ActiveConnection message to the aRtDeviceConnection instance. The aRtDeviceConnection instance performs the necessary steps to establish the connection to the other device. In step 1746, the RtDeviceProxy instance issues a sendMsg to the aRtDeviceConnection instance to send the create server message to the remote device. In step 1748, the aRtDeviceConnection instance sends the message to the remote device over the newly created connection.

Referring to FIGURE 19, an object commumcation diagram shows a method for creating a device connection for the passive, listening side of a connection. A request to establish a device connection is received from another workstation or controller/ multiplexer. The commimications services establishes a UDP communications connection with the requesting device.

Previous to creation ofthe connection, a device to be connected to is operating and contains an object aRtDeviceConnection which is ready to establish a connection. Object RtDevice Connection exists in the device and is listening for input messages in the form of a sync request. After the connection is created, a connection is established between the two devices and an RtDeviceConnection instance is created in the passive device to handle the connection.

In step 1810, object RtDeviceConnection receives a sync request message from a remote device. In step 1812, object RtDeviceConnection sends a Create message to object RtDeviceConnection to create a connection to the requesting device. Assuming that a device connection does not already exist, object RtDeviceConnection performs a createDeviceConnection in step 1814. In step 1816, object RtDeviceConnection creates an instance of RtDeviceConnection using template RtNew. In step 1818, object RtDeviceConnection registers the pointer to the RtDeviceConnection instance by sending a RegisterPointer message to the RtRegistry and returns the device connection object ID to object RtDeviceConnection. In step 1820, object RtDeviceConnection sends a Create message to object

RtDeviceProxy to create a device proxy for the requesting device. In step 1822, object RtDeviceProxy creates an instance of RtDeviceProxy using template RtNew. In step 1824, object RtDeviceProxy sends a GetDeviceConnectionlndex message to the object RtDeviceConnection to have the index ofthe device in the device connection table managed by RtDeviceConnection for later use. In step 1826, object RtDeviceProxy registers the pointer to the RtDeviceProxy instance by sending a RegisterPointer message to the RtRegistry and returns the device proxy object ID to RtDeviceConnection. In step 1828, object RtDeviceConnection passes the sync request message to the aRtDeviceConnection instance for processing via the handlelnboundMessagc method. In step 1830, object aRtDeviceConnection sends a sync response message back to the remote device to indicate successful completion ofthe Device Connection creation.

Referring to FIGURE 20, an object communication diagram illusttates a method for sending request/ response messages between devices. The remote object communications (ROC) service in one device sends a request message to the ROC service in another device. The request message is processed and a response message is sent back to the originating device.

Prior to sending messages, a UDP device connection is established between devices. Following the sending of request/ response messages between devices, a response message from a remote device has been received and is ready for processing by ROC services.

In step 1910, a read attribute request is issued by an application program to an aRtDeviceProxy instance associated with a remote device. In step 1912, the aRtDeviceProxy instance builds a request message to be sent to the remote device to read the attribute value and asks the RtRocReqRespService to send the message using the SendRequest method. In step 1914, object RtRocReqRespService sends the message to the instance of RtDeviceConnection associated with the connection to the remote device using the send_msg method. In step 1916, the instance of RtDeviceConnection then transmits the message to the remote device over the device connection. In step 1918, the instance of RtDeviceConnection in the remote device receives the message and requests the RtRocRouter class to route the message to the correct inbound message service. In step 1920, object RtRocRouter determines that the message is a request/response message and requests object RtRocReqRespService to ProcessInboundReqResp. After the message is processed by the ROC services and the message consumer a response message is built, in step 1922 object RtRocRqstRespService sends the response message to the originating device using the SendResponse method. In step 1924, the outbound message queue processing of RtRocReqRespService sends the response message to the instance of RtDeviceConnection associated with the connection to the source device using the send_msg method. In step 1926, the instance of RtDeviceConnection then transmits the response message back to the original device. In step 1928, the instance of RtDeviceConnection in the original device receives the message and requests the RtRocRouter class to route the message to the correct inbound message service. In step 1930, object RtRocRouter determines that the message is a request/response message and requests RtRocReqRespService to ProcessInboundReqResp.

Referring to FIGURE 21 an object communication diagram illusttates a method downloading a network configuration. A user, following completion ofthe device configuration for a system, initiates a download to a controller/ multiplexer. A device table configuration script is built by the configuration application. Using communications services , the configuration application establishes a device connection with the controller/ multiplexer to receive the download and sends a download script to the conttoller device. The controller/ multiplexer receives the download script messages and processes the device table. In step 2010, a configuration download application program builds remote object communications (ROC) script download messages containing the device table download script. In step 2012, the Download application issues a GetDevice message to RtDevice to get the Object LD for the RtDeviceProxy for the remote device. In step 2014, the RtDeviceProxy does not yet exist so a Create message is sent to RtDeviceProxyC to create the necessary device proxy object. In step 2016, RtDeviceProxyC sends a GetDeviceConnlndex message to RtDeviceConnection to get the index ofthe device connection for the remote device in the device connection table. In step 2018, the device connection does not yet exist so aRtDeviceConnection object is created to manage the connection to the remote device. A lookup is performed in the database to find the remote device entry. The device communications data (for example, ID and LP Addresses) is retrieved from the database and a new entry is added to the configuration devices connection table. This connection is marked permanent in the connection table since the device initiated the connection. In step 2020, a startActiveConnection message is sent to the aRtDeviceConnection object to establish a connection to the remote device. In step 2022, the aRtDeviceConnection sends an RtSyncMessage to the remote device. In step 2024, the remote device receives the RtSyncMessage and attempts to find an entry in the device connection table for the sending device. In step 2026, no entry is found so a new entry is added to the device connection table for the sending device and aRtDeviceConnection object is created to handle the connection in the receiving device. In step 2028, a RtSyncReplyMessage is created and sent back to the sending device containing the device connection index from the device table. The device connection is now established and ready to send and receive messages. In step 2030, the RtDeviceProxyC sends a create RtDeviceProxyS message to the remote device. In step 2032, the RtDeviceProxyS is created in the remote device. In step 2034, the Download Application sends the download scripts to the remote device via

RtRocReqRespServices using the SendMsg call. In step 2036, RtCommScriptDownload receives the Device Table script and processes each device table item and stores the data in a database Registry used to hold configuration data. For controller/ multiplexers this processing is used to create RtDeviceConnection objects and add the objects to the device connection table, allowing the memory to be acquired on download rather than subsequently.

The digital conttol system program 115 includes a diagnostic program and display routine for viewing diagnostic information relating to a process in a coherent manner, whether the diagnostic information is derived from a Fieldbus device or a nonFieldbus device. The digital conttol system program 115 advantageously incorporates diagnostic information relating to all devices within the process conttol environment 100 and presents this information to a user in a uniform manner using the diagnostic display routine so that the control sttategy and the diagnostic information are presented to a user as if all control actions and diagnostic information were performed or generated at a single location.

Referring to FIGURE 22, a pictorial view of a front-of-screen display illusttates a flowchart ofthe operations of a diagnostic display routine 2200 including a communication diagnostics program 2210. A user graphically views the status and integrity of workstations, conttollers and network links within the process conttol environment 100 using easily-recognized icons. The diagnostic display routine 2200 also generates summary status information for a device or network link segment. The diagnostic display routine 2200 displays detailed internal integrity information concerning devices connected to the network, including packets sent and received, the number of connections and the like. Some diagnostic information is accessed via modem to implement remote diagnostics functionality.

A workstation 102 or 104 and controller/ multiplexer 110 function in combination to supply detailed diagnostic information about the status ofthe communications subsystem in connected devices including detailed integrity information about the status ofthe ACN communications links, device connections, ethernet statistics, and communications stack diagnostic information. A diagnostic check of communication functionality is also supported. The communication diagnostics 2210 support three levels of diagnostics information including basic diagnostics for the entire network, diagnostic information for a single device and diagnostic information for a single device connection.

At the basic network diagnostic level, the communication diagnostics 2210 gather information from all network devices and present the information to a user. The communication diagnostics 2210 collect information from remote controller/multiplexers 110 on demand or as a background task executing periodically. The communication diagnostics 2210 send network communications status requests to a diagnostic port of a particular device to determine integrity ofthe communications path to that device.

A response to a network communications status request contains communications integrity information including device type information indicative of whether the device is a controller or workstation, and primary and secondary status summary information. The Connection Status Summary, which is set to "Bad" if an error exists on the link, is added as an attribute to a Communications Subsystem Module, allowing a user to display these values on the operator interface upon request.

The communication diagnostics 2210 request diagnostic information from each device connected into the process conttol environment 100 so that the status ofthe communications links between the device and a remote device are displayed.

The communications diagnostics 2210 monitor and display diagnostic information for a single device to supply detailed diagnostic information about communications for a particular device, including link status information for device connections and the ethernet statistics for ethernet interfaces in the device. The communications diagnostics 2210 request the device commumcations status using an appropriate diagnostic remote object communications (ROC) message. The device communications status includes information such as a Device Table Index, a Device ID, a Device Connection State (Ready, Synching, ACK Pending, Closed), a Primary Device Address, a Secondary Device Address, a Link Status and diagnostic information for a single device connection.

Ethernet statistical information is held in counters which start counting when the device is booted and are not reset until reboot ofthe device. The counts are implemented as attributes to the Communications subsystem module as part ofthe module attributes and include input error information including numbers of total input errors, input CRC errors and input overrun errors. Output error information includes numbers of total output errors, output late collisions, output collisions exceeding a preselected number, output overrun errors and output carrier lost errors. Other counts include the numbers of packets received, packets sent, bytes received, bytes sent, broadcast packets received, broadcast packets sent, unknown protocol messages received, transmit deferrals, single collision transmits and multiple collision transmits.

The communications diagnostics 2210 also monitor and display detailed diagnostic information for a particular device connection in a particular device. When a user requests device connection statistics, the communications diagnostics 2210 designate a destination device ID for a connection. Device connection statistics contain link status information and statistical information for the designated device connection, including a Device Connection State (Ready, Synching, ACK Pending, Closed), a Remote Primary Address (Primary ACN IP Address for the destination device), a Remote Secondary Address (Secondary ACN EP Address for this device or 0), a Primary Link Status (Good/Bad), a Secondary Link Status (Good/Bad). The statistics also include counts of messages received on Primary Link, messages received on Secondary Link, messages sent on Primary Link, messages sent on Secondary Link, Synchs Sent, Synchs Received, ACK Time-outs on Primary Link, and ACK Time-outs on Secondary Link.

The commumcations diagnostics 2210 support checking of a communications path between two devices in a network. A first device sends a message, such as an evoking message, over a specified communication link to a remote device. The remote device echoes the message back to the sender. A successful evoking message and echo are indicative that the communications subsystem is functional in the remote device. This interaction is different from a normal TCP/LP ping which is handled completely by an ethernet hardware driver.

Referring to FIGURE 23, an object communication diagram illusttates a method for one device to check whether another device exists on a network. A diagnostic application program which is either part of the process conttol environment or a stand-alone application monitors to determine whether a remote device exists on an ACN network and, if so, whether the remote device is capable of communication. The diagnostic application program sends a message to the remote device and expects to receive the message echoed from the remote device or a time-out.

In step 2310, a diagnostic application program sends a Ping message to object RtCommDiag requesting that a communication inquiry (ping) be performed to a specified device name or address. In step 2312, object RtCommDiag creates a communications socket to perform the inquiry. In step 2314, object RtCommDiag creates an RtEchoMessage to send to the remote device. In step 2316, object RtCommDiag sends the RtEchoMessage to the specified device using RtCommSendTo and waits for the message to be echoed back from the remote device. In step 2318, object RtDeviceConnection in the remote device receives the RtEchoMessage and processes the message using the HandleDiagnosticMessage method. In step 2320, object RtDeviceConnection immediately returns an RtEchoMessage with a diag code of echo response to object RtCommDiag in the source device using RtCommSentToMessage. In step 2322, object RtCommDiag receives the echo response message and returns a successful status to the diagnostic application. If no response is received from the remote device, in step 2324, object RtCommDiag returns a failed status to the diagnostic application. In step 2326, object RtCommDiag closes the socket created to perform the inquiry.

Referring to FIGURE 24, an object communication diagram illusttates a method for requesting device commumcations diagnostics. A diagnostic application program requests, accesses and displays the status of all device connections in a remote device. The diagnostic application program sends a request for the required diagnostic information to the remote device and waits for a response. Once the response is received, all device connections and device status in the remote device are displayed to the user. This information may be communicated in multiple messages so that the diagnostic application program makes multiple requests for diagnostic data. In step 2410, a Diagnostic Application program sends a GetDeviceCommDiags request to object RtCommDiag to request communications diagnostics for the device connections in the remote device. In step 2412, object RtCommDiag sends a GetDeviceConnectionlndex message to object RtDeviceConnection to request the device connection table index for the remote device. In step 2414, object RtCommDiag issues a Create to object RtRocMessage to create a message to be used to request diagnostic information. In step 2416, object RtRocMessage creates a new instance of aRtRocMessage to be used for the diagnostic request. In step 2418, object RtCommDiag builds the message to be sent and issues a SendRequest to RtRocReqRespService to send the message to the remote device. In step 2420, object RtCommDiag issues a waitForResponse to the aRtRocMessage instance created for the diagnostic request message. In step 2422, object RtRocReqRespService performs a send_msg on the instance of aRtDeviceConnection associated with the remote device. In step 2424, the aRtDeviceConnection instance transmits the request message to the remote device. In step 2426, object RtDeviceConnection the remote device receives the message and issues a handlelnboundMessage to the aRtDeviceConnection instance associated with the sending device. In step 2428, the aRtDeviceConnection instance passes the message off to RtRocRouter via the Route method for processing. In step 2430, object RtRocRouter responds to the message by issuing a

ProcessInboundReqResp to the RtRocReqRespService. In step 2432, the RtRocReqRespService determines the message type from the request message ID and issues a perform command on the RtRocDevConDiagListMsg message. In step 2434, RtRocDevConDiagListMsg sends a GetDiagList message to object RtDeviceConnection to get the device connection diagnostic data for the device connections in this device. In step 2436, object RtDeviceConnection puts the diagnostic data into a data buffer using various fill routines provided by the utility class RtDevConDiagListData. In step 2438, RtRocDevConDiagListMsg then performs a CreateResponse to create the response message containing the diagnostic data. In step 2440, RtRocDevConDiagListMsg issues a storeOn message to RtDevConDiagListData to put the diagnostic data into the response message. In step 2442, RtRocDevConDiagListMsg sends the response message back to the requesting device through

RtRocReqRespService using the SendResponse method. In step 2444, RtRocReqRespService performs a send_msg to the aRtDeviceConnection instance associated with the requesting device. In step 2446, the aRtDeviceConnection instance transmits the response message back to the requesting device. In step 2448, the aRtDeviceConnection instance in the requesting device receives the response message from RtDeviceConnection via a handlelnboundMessage. The response message is then send to RtRocRouter using the Route method. In step 2450, RtRocRouter performs a ProcessInboundReqResp on RtRocReqRespService. In step 2452, RtRocReqRespService informs the aRtRocMessage instance that the response to the original request for diagnostic data is available. In step 2454, RtCommDiag issues a readFrom to RtDevConDiagListData to retrieve the diagnostic data from the response message. In step 2456, RtCommDiag passes the data back to the Diagnostic Application which issues getData messages to RtDevConDiagListData to retrieve the diagnostic data for display. The requesting device returns a buffer containing the general diagnostics for all device connections actively in place. Referring to FIGURE 25, an object communication diagram illusttates a method for requesting device connection commumcations diagnostics. A diagnostic application program requests, accesses and displays the detailed status of a single device connection existing in a remote device. The diagnostic application program sends a request for device connection statistics information to the remote device and waits for a response. Once the response is received, the device connection statistics for the device connection are displayed to the user. In step 2510, a Diagnostic Application program sends a GetDeviceConDiags request to RtCommDiag to get the device connection statistics for a specific device connection in the remote device. In step 2512, RtCommDiag sends a GetDeviceConnectionlndex message to RtDeviceConnection to get the device connection table index for the remote device. In step 2514, RtCommDiag issues a Create to RtRocMessage to create a message to be used to request the diagnostic information. In step 2516,

RtRocMessage creates a new instance of aRtRocMessage to be used for the diagnostic request. In step 2518, RtCommDiag builds the message to be sent and issues a SendRequest to RtRocReqRespService to send the message to the remote device. In step 2520, RtCommDiag issues a waitForResponse to the aRtRocMessage instance created for the diagnostic request message. In step 2522, RtRocReqRespService performs a send msg on the instance of aRtDeviceConnection associated with the remote device. In step 2524, the aRtDeviceConnection instance transmits the request message to the remote device. In step 2526, RtDeviceConnection in the remote device receives the message and issues a handlelnboundMessage to the aRtDeviceConnection instance associated with the sending device. In step 2528, the aRtDeviceConnection instance passes the message to RtRocRouter via the Route method for processing. In step 2530, RtRocRouter determines that the message is a request response type message and issues a

ProcessInboundReqResp to the RtRocReqRespService. In step 2532, the RtRocReqRespService determines the message type from the request message ED and issues a perform command on the RtRocDevConDiagDetailMsg message. In step 2534, RtRocDevConDiagDetailMsg sends a GetDiagDetail message to RtDeviceConnection to get the device connection statistics for the requested device connection. In step 2536, RtDeviceConnection puts the diagnostic data into a data buffer using various fill routines provided by the utility class RtDevConDiagDetailData. In step 2538, RtRocDevConDiagDetailMsg performs a CreateResponse to create the response message containing the diagnostic data. In step 2540, RtRocDevConDiagDetailMsg issues a storeOn message to RtDevConDiagDetailData to put the diagnostic data into the response message. In step 2542, RtRocDevConDiagDetailMsg sends the response message back to the requesting device through

RtRocReqRespService using the SendResponse method. In step 2544, RtRocReqRespService performs a send_msg to the aRtDeviceConnection instance associated with the requesting device. In step 2546, the aRtDeviceConnection instance transmits the response message back to the requesting device. In step 2548, the aRtDeviceConnection instance in the requesting device receives the response message from RtDeviceConnection via a handlelnboundMessage. The response message is sent to RtRocRouter using the Route method. In step 2550, RtRocRouter performs a ProcessInboundReqResp on RtRocReqRespService. In step 2552, RtRocReqRespService informs the aRtRocMessage instance that the response to the original request for diagnostic data is available. In step 2554, RtCommDiag issues a readFrom to RtDevConDiagDetailData to retrieve the diagnostic data from the response message. In step 2556, RtCommDiag passes the data back to the Diagnostic Application which issues getData messages to RtDevConDiagDetailData to retrieve the diagnostic data for display.

Generally, a controller/ multiplexer 110 is manually added to a network. For example, a device is typically added to a network when a user selects the ACN Segment onto which the device is to be connected and issues a 'New Device' command. The user is prompted for the device type, either workstation or controller/ multiplexer, the device name and a comment field. A configuration system automatically assigns the next Device TD to the device and builds a default name based on the Device ID. Optionally, the configuration system automatically generates primary and secondary EP addresses and subnet masks for the device based on PCN number and the previously assigned Device ID.

Alternatively, a controller/ multiplexer is automatically sensed and incoφorated into a run-time system as shown in FIGURE 26. In step 2610, a controller/ multiplexer, upon connection to the ACN and application of power, automatically sends a request for identification or verify IP address assignment. The request message includes the MAC address ofthe controller/ multiplexer. The request is handled by a "Plug&Play Network Configuration Service", which is known in the operating system art, at a master configuration controller/ multiplexer in step 2612. In step 2614, the "Plug&Play Network Configuration Service" receives the request from the network to assign/ verify an EP address, searches a table of configured devices for a MAC address match. If a match is found, in step 2616 the "Plug&Play Network Configuration Service" responds with the Device Name, Device LD, EP Address Information, Subnet Mask Information, ACN Segment Number and other items included in the Device Table. If no match is found, in step 2618 the "Plug&Play Network Configuration Service" automatically generates a default name for the device based on the controller/ multiplexer MAC address (for example, Controller-000001). The new device is added to the database in a Device Scratch area in step 2620.

In step 2622, using the Explorer™ a user selects each unassigned controller/ multiplexer in the Device Scratch area, drags the selection to the appropriate ACN segment and, and either adds the selection to the system as a new device or drops the selection to a pre-existing device configuration. If the unassigned controller/ multiplexer is added as a new device, the configuration processing proceeds in the manner of manual incoφoration ofthe device. In step 2624, a user is prompted for the real device name using the previously assigned name 'Conttoller-000001 ' as a default. If automatic address assignment is set, the new device is assigned the next Device ID and associated EP addresses and Subnet masks are automatically assigned in step 2626. If manual address assignment is set, the device is automatically assigned the next Device ED and the user is prompted to enter the EP Addresses and Subnet Masks in step 2628. The MAC address for the controller/ multiplexer is set to the MAC address ofthe 'Controller-OOOOOl' as dragged into the ACN segment. The new controller/ multiplexer Name, Device ED, LP Address, Subnet Masks and ACN number are added to the device table in the database. The next request by an unconfigured controller/ multiplexer is answered by the "Plug&Play Network Configuration Service". If a new controller/ multiplexer is dragged and dropped over an existing device, that device must be a controller/ multiplexer type device and have an unassigned MAC address. Accordingly, the MAC address ofthe previously entered controller/ multiplexer is set to the MAC address ofthe 'Conttoller-OOOOOl' device which was dropped. The new controller/ multiplexer Name, Device ID, IP Addresses, Subnet Masks and ACN number are available for sending to the requesting controller/ multiplexer by the "Plug&Play Network Configuration Service".

The digital conttol system program 115 includes an auto-configure routine for automatically configuring the input/output (I/O) subsystem in response either to an "auto-configure" command by a user or in response to detection of a new controller/multiplexer.

Referring to FIGURE 27, a flow chart illusttates steps of an automatic configuration routine for configuring a physical I/O device. An auto-configure command may be directed to a Controller/Multiplexer 110, causing each I/O subsystem in the Controller/Multiplexer 110 to auto-configure. An auto-configure command may be directed to an I O subsystem, causing each I/O Card in the I/O subsystem to auto- configure. An auto-configure command may also be directed to an I/O Card.

The auto-configure operation for an I/O Card first inteπogates the I/O Card at a particular card position to determine a Card Type in step 2710 and, implicitly for some I/O Cards, the number of I/O Ports in the I/O Card. If no I/O Card is previously created in the engineering database for that card position, an I/O Card ofthe appropriate type is defined and the appropriate number of I/O Ports are created in step 2712. If an I O Card does exist in the engineering database for that card position, but the Card Type in the engineering database does not match the Card Type sensed at the card position, the auto-configure operation generates a graphic notification ofthe mismatch in step 2714 and interrogates a user to determine whether the engineering database is to be changed to include the sensed Card Type. The Card Type in the engineering database is changed to the sensed Card Type in step 2716 if requested by the user.

Once the Card Type is known, the auto-configuration program interrogates each I/O Port in accordance with the Card Type in step 2718 to determine the Port Type and, if information is available, the number of I/O Devices on the I/O Port. If no I/O Port is previously created in the engineering database for that port address, an I/O Port ofthe appropriate type is defined and the appropriate number of I/O Devices are created in step 2720. Ef an I/O Port exists in the engineering database for the Port address, but the Port Type does not match the type ofthe sensed I/O Port, the user is notified ofthe mismatch in step 2722, and asked whether the engineering database is to be changed to match the sensed I/O Port in step 2724. The Port Type in the engineering database is changed to the sensed Port Type in step 2726 if requested by the user.

Once the Port Type is known, the auto-configuration program inteπogates each I/O Device in accordance with the Port Type in step 2728 to determine the Device Type. Ef no I/O Device is previously created in the engineering database for that device address, an I/O Device ofthe appropriate type is defined in step 2730. If an I/O Device exists in the engineering database for the Device address, but the Device Type does not match the type ofthe sensed I/O Device, the user is notified ofthe mismatch in step 2732, and asked whether the engineering database is to be changed to match the sensed I/O Device in step 2734. The Device Type in the engineering database is changed to the sensed Device Type in step 2736 if requested by the user.

In step 2738, instrument signal tags (ISTs) are automatically created for primary signal sources on the I/O Ports and I/O Devices, unless an 1ST already exists with the identical signal source path.

Referring to FIGURE 28, a front-of-screen display, also called a "screen" 2800, for a graphical user interface (GUI) depicts a display of a system configuration. The screen 2800 depicts navigation selections which are operated by a user to select, construct and operate a process control configuration. The navigation program supplies an initial state for navigating across various tools and processors in a network. A user controls the navigation program to access libraries, areas, process conttol equipment and security operations.

The illustrative system configuration is described and controlled with respect to a conttol system setup 2802, conttol strategies 2804, and a physical setup 2806. The functions of automatically sensing and automatically configuring a conttol system relate to the physical setup 2806. In particular, the functions of automatically sensing and automatically configuring physical devices in a conttol system relate to the commission and activation of devices in the conttol network 2808, and the decommissioning of conttollers 2810.

In an illustrative embodiment, a process conttol system controls various devices attached to a process conttol network in accordance with a Fieldbus standard protocol. In the Fieldbus protocol, a standard user application is defined based on blocks. A block is a representation of various different types of application functions. Types of blocks include resource blocks, function blocks, and ttansducer blocks.

A resource block describes characteristics of a fieldbus device such as a device name, manufacturer, and serial number. A device includes only a single resource block.

A function block defines the conttol system behavior. Input and output parameters of function blocks may be linked over the fieldbus. The execution of each function block is precisely scheduled. A user application may include numerous function blocks. Examples of standard function blocks include analog input (Al), analog output (AO), bias (B), Conttol Selector (CS), Discrete Input (DI), Discrete Output (DO), Manual Loader (ML), Proportional Derivative (PD), Proportional/ Integral/ Derivative (PED) and ratio (RA). Function blocks are built into fieldbus devices to define a selected device functionality. In one example, a simple temperature transmitter may contain an Al function block. A conttol valve often includes a PED function block and an AO block.

A ttansducer block decouples function blocks from local input and output functions for reading sensors and commanding output hardware. Transducer blocks contain information such as calibration data and sensor type. Typically a user application uses one ttansducer block for each input or output function block.

Another object defined in the user application includes link objects for defining the links between function block inputs and outputs internal to the device and across the fieldbus network. Trend objects allow local trending of function block parameters for access by other devices. Alert objects are used to allow reporting of alarms and events on the fieldbus. View objects are predefined groupings of block parameter sets that are used in the human/ machine interface. The function block specification defines four views for each type of block.

Referring to FIGURE 29, a state transition diagram illusttates the various states of a field device. The field device states include an offline state 2902, an unrecognized state 2904, a standby state 2906, a commissioned state 2908, and an unbound state 2910. The state of a field device is determined by several parameters including a system management state (SM-State), a physical device tag (PD-Tag), a device address, device revision information (Rev*), and a device identification (Device-ID). In the illustrative embodiment, a device in the commissioned state 2908 is a Fieldbus device that is available for control sttategy configuration and installation. A decommissioned device is a device that has been removed from the commissioned state 2908.

Several events occur that generate a state transition of a plurality of state transitions Tl through T14. One or more actions are performed during each state transition.

A state transition Tl is caused by the event in which a field device residing at a temporary address is queried with a system management identify service (SM-IDENTIFY) and the query determines that the device has a cleared physical device tag. The state transition Tl changes from a NULL state to an OFFLENE state by allocating a standby address for the field device. Executing logic, typically in the form of firmware, software, or hardware, executes a set physical device tag service (SET-PD-TAG) to set the physical device tag identical to the device identification ofthe field device. Executing logic also uses a set device address service (SET-ADDRESS) to send a standby address to the field device.

A state transition T2 is caused by the event in which a field device residing at a temporary address is queried with a system management identify service (SM-EDENTIFY) and the query determines that the device has a physical device tag that is identical to the device identification ofthe device. The state transition T2 changes from a NULL state to an OFFLINE state by allocating a standby address for the field device. Executing logic uses a set device address service (SET-ADDRESS) to send a standby address to the field device.

A state transition T3 is caused by the event in which a field device residing at a temporary address is queried with a system management identify service (SM-EDENTIFY) and the query determines that the device has a physical device tag and a device identification configured for the cuπent process conttol system network link. The state ttansition T3 changes from a NULL state to an OFFLINE state using executing logic that employs the set device address service (SET-ADDRESS) to send an assigned address to the field device.

A state ttansition T4 is caused by the event in which a field device residing at a temporary address is queried with a system management identify service (SM-IDENTIFY) and the query determines that the device has a physical device tag and a device identification not configured for the current process conttol system network link. The state ttansition T4 changes from a NULL state to an UNRECOGNIZED state.

A state ttansition T5 is caused by an event in which the device appears at a temporary address and the device is being commissioned by a user. The state ttansition T5 changes from an OFFLENE state to an OFFLINE state using executing logic, typically in the form of firmware, software, or hardware, that executes a set physical device tag service (SET-PD-TAG) to clear the physical device tag ofthe field device.

Executing logic also executes a set physical device tag service (SET-PD-TAG) to send an assigned physical device tag to the field device. Executing logic further uses a set device address service (SET- ADDRESS) to send an assigned address to the field device.

A state ttansition T6 is caused by an event in which the device appears at a temporary address and the device is being decommissioned by a user. The state ttansition T6 changes from an OFFLINE state to an OFFLENE state using executing logic that executes a set physical device tag service (SET-PD-TAG) to clear the physical device tag ofthe field device.

A state ttansition T7 is caused by an event in which a user requests to place a decommissioned device in standby. The state transition T7 changes from an OFFLINE state to an OFFLINE state by allocating a standby address for the field device. Executing logic executes a set physical device tag service (SET-PD- TAG) to set the physical device tag identical to the device identification ofthe field device. Executing logic also uses a set device address service (SET-ADDRESS) to send a standby address to the field device.

A state ttansition T8 is caused by an event in which the field device appears at the standby address. The state ttansition T8 changes from an OFFLINE state to a STANDBY state through executing logic that reads device revision information from the resource block.

A state ttansition T9 is caused by an event in which the field device appears at the assigned address. The state ttansition T9 changes from an OFFLINE state to a COMMISSIONED.

A state transition T10 is caused by a user requesting to commission a device in the STANDBY state. The state ttansition T10 changes from the STANDBY state to the OFFLINE state through executing logic that uses a clear address service (CLEAR-ADDRESS) to clear the device address.

A state ttansition Tl 1 is caused by a user requesting to decommission a device in the STANDBY state. The state ttansition Til changes from the STANDBY state to the OFFLINE state through executing logic that uses a clear address service (CLEAR-ADDRESS) to clear the device address. A state ttansition T12 is caused by a user requesting to decommission a device in the COMMISSIONED state. The state ttansition T12 changes from the COMMISSIONED state to the OFFLINE state through executing logic that uses a clear address service (CLEAR-ADDRESS) to clear the device address.

A state ttansition T13 is caused by a user requesting to decommission a device in the INITIALIZED state ofthe Fieldbus system management states. The state ttansition T13 changes from the UNRECOGNIZED state to the OFFLENE state through executing logic that executes a set physical device tag service (SET-PD-TAG) to clear the physical device tag ofthe field device.

A state transition T14 is caused by a user requesting to decommission a device in the SM- OPERATIONAL state ofthe Fieldbus system management states. The state ttansition T14 changes from the UNRECOGNIZED state to the OFFLINE state through executing logic that uses a clear address service (CLEAR-ADDRESS) to clear the device address.

In accordance with the Fieldbus standard, to operate properly a Fieldbus device has a unique device address (network address) and a unique physical device tag. Each device connected to the process conttol system network link has a unique node designator. A data link specification specifies a range of allowable values for node designators including a range for permanent devices, a range for temporary addresses, and a range for visitor devices. The temporary addresses are used by devices that are not presently in the SM- OPERATIONAL state. The Fieldbus interface maintains partitioning ofthe address space for permanent devices into three sets. One set, called "assigned addresses", includes addresses assigned to devices with a specific physical device tag, regardless of whether the device is present on the bus. The assigned addresses is assigned using a software engineering tool on the basis of information input by a user relating to Link- Active-Scheduler takeover preference. A second set, termed "standby addresses", describes devices in the SM-OPERATIONAL state but have no device addresses assigned. The standby addresses are managed by the Fieldbus interface. The third set of addresses are addresses outside the first and second sets and refer to unused addresses.

The small number of temporary addresses complicates autosensing and online address assignment. Standby addresses are defined and utilized to support functionality ofthe autosensing and online address assignment operations. The assigned address set and the standby address set are defined to be equal to the number of potential devices connected to the process control system network link. For example, if sixteen devices may be potentially connected to the process conttol system network, then sixteen assigned addresses are defined and sixteen standby addresses are defined.

The device revision information includes a manufacturer's identification (MANUF AC-ID), a device type (DEV-TYPE), a device revision (DEV-REV), and a device description revision (DD-REV). In the offline state 2902 a field device is recently attached to a process control system network or is in the process of being commissioned or decommissioned. The offline state 2902 includes device states having a plurality of parameter combinations. In a first offline state 2902, the system management state is UNINITIALIZED and the physical device tag is cleared. In a second offline state 2902, the system management state is INITIALEZED and the physical device tag is read from the physical device and displayable on a screen. In either ofthe offline states 2902, the device address is a temporary address, the revision information is not available, and the device identification is read from the device and displayable on the screen.

In the unrecognized state 2904, the field device physical device tag and the device identification do not match the values that are commissioned for a device that is connected to the process conttol system network. The unrecognized state 2904 includes device states having a plurality of parameter combinations. In a first unrecognized state 2904, the system management state is ENITIALLZED with a device address that is a temporary address. In a second unrecognized state 2904, the system management state is SM- OPERATIONAL with a device address that is a standby address or an assigned address. In either unrecognized state 2904, the physical device tag is read from the device and displayable on the screen, the device revision is not available, and the device identification is read from the device and displayable on the screen.

In the standby state 2906, the field device is not yet autosensed and is therefore not available for configuration in the conttol strategy or included in Link- Active-Scheduler (LAS) schedules ofthe system management configuration. In the standby state 2906, function block execution and link communications are disabled. Note that a Link-Active-Scheduler is a deterministic centralized bus scheduler that includes a list of transmit times for all data buffers in all devices that are to be cyclically transmitted. When a device is due to send a data buffer, the Link-Active-Scheduler issues a compel data (CD) message to the device. Upon receipt ofthe CD message, the device broadcasts or "publishes" the data in the buffer to all devices on a field device bus and the broadcasting device is defined to be a "publisher". Any device that is configured to receive the data is defined to be a "subscriber". Scheduled data transfers are typically used for the regular, cyclic ttansfer of conttol loop data between devices on the fieldbus.

In the standby state 2906, the system management state is SM-OPERATIONAL, the physical device tag is equal to the device identification, and the device address is a standby address. The device revision information is read from the field device and displayable. The device identification is read from the device and displayable on the screen.

The unbound state 2910 is a configuration placeholder for a field device that is to be physically attached subsequently. The unbound state 2910 supports configuration of conttol strategies utilizing the function blocks in a field device that is not yet connected. In the unbound state 2910, the system management state is not yet applicable but the physical device tag is specified by a user and the device address is assigned by the user. The device revision information set according to the most recent commission or configuration. The device identification is cleared.

In the commissioned state 2908, the field device is available for conttol strategy configuration and installation. The system management state is SM-OPERATIONAL, the physical device tag is specified by a user, and the device address is assigned by the user. The device revision information is read from the field device and displayable on the screen. The device identification is read from the field device, stored in a field configuration database, and displayable on a display screen.

Several operations or "use cases" are defined for controlling commissioning and decommissiomng of field devices.

Referring to FIGURE 30, a flow chart illustrates a first operation or "use case" which describes an operation of commissioning a new device 3000. Prior to the commissioning ofthe new device, the Fieldbus interface is operational. A device is connected to the process control system network. The device either has no physical device tag or has a physical device tag that is equal to the device identification.

The operation of commissioning a new device 3000 results in a condition in which the device is assigned a new physical device tag and a device address, and the device is ready for function block configuration. The new field device is entered into the process control system network database with the device identification bound and the device revision information set. An engineering software tool that displays the process conttol system network status displays the new device as a COMMISSIONED device.

In a first step 3002, the field device appears in the "live list" at a temporary address. A "live list" is a list of all devices that are properly responding to a pass token (PT) message. All devices on a fieldbus are allowed to send unscheduled messages between the transmission of scheduled messages. The Link- Active- Scheduler grants permission to a device to use the fieldbus by issuing a pass token (PT) message to the device. When the device receives the PT, it is allowed to send messages until the messages are complete or until a maximum allotted token hold time has expired. As a highest priority activity, the Link-Active- Scheduler accesses a CD schedule containing a list of actions that are set to occur on a cyclic basis. At a scheduled time, the Link-Active-Scheduler sends a compel data (CD) message to a specific data buffer in the fieldbus device. The device immediately broadcasts a message to all devices on the fieldbus. The Link- Active-Scheduler performs remaining operations between scheduled transfers. The Link-Active-Scheduler continually adds new devices to the field bus by periodically sending probe node (PN) messages to addresses that are not on the live list. If a device is present at the address and receives the PN, the device immediately returns a probe response (PR) message. If a device responds with the PR message, the Link- Active-Scheduler adds the device to the live list and confirms by sending the device a node activation (NA) message. A device remains on the live list so long as the device responds properly to PTs. When a device is added or removed from the live list, the Link-Active-Scheduler broadcasts changes to the live list to all devices to allow each device to maintain a cuπent copy of the live list. In a second step 3004, the interface queries the field device using a system management identify service (SM-EDENTEFY) and determines whether the field device is in the UNINITIALIZED state with no physical device tag set or in the INITIALIZED state having a physical device tag that is equal to the device identification. The interface then allocates 3006 a standby address for the field device.

A logical step 3008 directs that a previously UNINETEALLZED device, in step 3010, sets the physical device tag ofthe field device identical to the device identification using a set physical device tag service (SET-PD-TAG), thereby placing the field device in the INITIALIZED state. The standby address is sent to the field device 3012 using a set address service (SET-ADDRESS), advancing the field device from the INITIALIZED state to the SM-OPERATIONAL state. At this point the field device appears in the "live list" at a standby address 3014. Device revision information is read from the resource block 3016. In step 3018, an executing software engineering tool displays the field device as a STANDBY device.

In step 3020, a new user assigns a new physical device tag to the field device. The physical device tag is constrained to be unique and not the same as the device identification. During the assignment ofthe physical device tag, a device address is assigned to the field device using a software engineering tool and the Link-Active-Scheduler takeover preference is set to "selectable". The device revision information is read from the field device and written to the process conttol system network database. The interface changes the state ofthe field device 3022 to the INITIALIZED state using a clear address service (CLEAR-ADDRESS). The field device appears in the "live list" at a temporary address 3024.

In a step 3026, the interface queries the field device using a system management identify service (SM-EDENTIFY) and recognizes the field device by the device identification. The interface uses the set physical device tag service (SET-PD-TAG) to clear the physical device tag 3028, thereby changing the field device state to the UNENITIALEZED state. The set physical device tag service (SET-PD-TAG) is then used to send the assigned physical device tag to the field device 3030, changing the field device state to the ENΓTIALIZED state. The set address service (SET-ADDRESS) is called to send the assigned address to the field device 3032, placing the field device in the system management operational state (SM- OPERATIONAL). The field device appears in the "live list" at the assigned address 3034. In the process conttol system network database, the device identification is bound 3036 to the device. The software engineering tool displays the field device as a COMMISSIONED device.

Referring to FIGURE 31, a flow chart illusttates a second operation or 'use case" which describes an operation of commissioning an unbound device 3100. Prior to the commissioning of the unbound device, the Fieldbus interface is operational. A field device has been created in the process conttol system network database and a physical device tag and a device address are assigned to the field device. However, the field device is not bound to a device identification. The process conttol system network database has also been initialized to contain device revision information read from the field device. A software engineering tool displays the field device as an UNBOUND device. The UNBOUND device to be commissioned is either a field device with no physical device tag or a field device having a physical device tag that is identical to the device identification. The UNBOUND field device is commissioned to place the field device on the process conttol system network link.

The operation of commissioning an UNBOUND device 3100 results in a condition in which the device is configured with a physical device tag and an assigned device address, and the device is ready for function block configuration. The new field device is entered into the process conttol system network database with the device identification bound. An engineering software tool that displays the process conttol system network status displays the device as a COMMISSIONED device.

In a first step 3102, the field device appears in the "live list" at a temporary address. In a second step 3104, the interface queries the field device using a system management identify service (SM-EDENTIFY) and determines whether the field device is in the UNINITIALIZED state with no physical device tag set or in the INITIALIZED state having a physical device tag that is equal to the device identification. The interface then allocates 3106 a standby address for the field device.

A logical step 3108 directs that a previously UNINITIALIZED device, in step 3110, sets the physical device tag ofthe field device identical to the device identification using a set physical device tag service

(SET-PD-TAG), thereby placing the field device in the INITIALIZED state. The standby address is sent to the field device 3112 using a set address service (SET-ADDRESS), advancing the field device from the INITIALIZED state to the SM-OPERATIONAL state. At this point the field device appears in the "live list" at a standby address 3114. Device revision information is read from the resource block 3116. In step 3118, an executing software engineering tool displays the field device as a STANDBY device.

In step 3120, a user assigns a physical device tag to the field device by associating the field device with the pre-configured device. The device revision information is read from the field device to ascertain that the information matches the device revision information in the process conttol system network database for the pre-configured device. If the device revision information ofthe device does not match the database, the user may override the database, reading the device revision information from the field device and writing the information to the process conttol system network database. Alternatively, the device revision information for an UNBOUND device may be made blank, allowing any physical device to be bound with the UNBOUND device. The interface changes the state ofthe field device 3122 to the INITIALIZED state using a clear address service (CLEAR-ADDRESS). The field device appears in the "live list" at a temporary address 3124.

In a step 3126, the interface queries the field device using a system management identify service

(SM-LDENTEFY) and recognizes the field device by the device identification. The interface uses the set physical device tag service (SET-PD-TAG) to clear the physical device tag 3128, thereby changing the field device state to the UNINITIALIZED state. The set physical device tag service (SET-PD-TAG) is then used to send the assigned physical device tag to the field device 3130, changing the field device state to the INITIALIZED state. The set address service (SET-ADDRESS) is called to send the assigned address to the field device 3132, placing the field device in the system management operational state (SM- OPERATIONAL). The field device appears in the "live list" at the assigned address 3134. In the process conttol system network database, the device identification is bound 3136 to the device. The software engineering tool displays the field device as a COMMISSIONED device.

Referring to FIGURE 32, a flow chart illusttates a third operation or "use case" which describes an operation of decommissioning a device 3200. A field device is decommissioned for several reasons. For example, when a Fieldbus device is obsolete, a user may wish to clear a network interconnection structure of nonfunctioning branches so that the process conttol system no longer expends resources on the obsolete device. Also, a user may suspect that a Fieldbus device is malfunctioning and degrading operations of a segment of a network interconnection structure. The user may diagnose the problem by having the process conttol system ignore the suspected Fieldbus device temporarily to determine whether the remaining devices in the segment operate properly.

Prior to the operation of decommissioning a device, the Fieldbus interface and the field device are operational and the field device appears in the live list at the assigned or standby address. A software engineering tool displays the field device as a COMMISSIONED or STANDBY device. The software engineering tool executes a routine that prepares the field device for decommissioning, for example by clearing function block tags and clearing an OPERATIONAL-POWERUP flag.

The operation of decommissioning a device results in a condition in which the physical device tag of the field device is cleared and the field device is prepared to be removed from the process conttol system network link. The process conttol system network database entry for the field device designates the device identification as in an unbound condition. The software engineering tool displays the device identification as an UNBOUND device and displays the physical device as an OFFLINE device.

The operation of decommissioning a device 3200 begins when a user selects a "Decommission" operation for the field device 3202. A graphic user interface includes a software engineering tool that issues a "Decommission" command to an appropriate conttoller within the process conttol system. The decommission command specifies a target I/O subsystem, card and port identifiers, and the device identification ofthe field device to be decommissioned. The device identification is specified since another device with the same physical device tag may be present in an UNRECOGNIZED state. The interface changes the state ofthe field device 3204 to the INITIALIZED state using a clear address service (CLEAR- ADDRESS). The field device appears in the "live list" at a temporary address 3206.

In a step 3208, the interface queries the field device using a system management identify service (SM-EDE lJh^'Y) and recognizes the field device by the physical device tag and the device identification. The interface uses the set physical device tag service (SET-PD-TAG) to clear the physical device tag 3210, thereby changing the field device state to the UNINITIALIZED state. In the process control system network database, the device identification is unbound and the software engineering tool displays the field device as an UNBOUND device 3212. In a next step 3214, the software engineering tool displays the field device as an OFFLINE device.

A network interface card stores a designation that the field device has been decommissioned 3216 and does not move the field device to a STANDBY address unless directed by the user. If the decommissioned device is not move to a STANDBY address, the interface card tracks the field device until the field device advances off the live list.

Referring to FIGURE 33, a flow chart illusttates a fourth operation or "use case" which describes an operation of attaching a commissioned device without enablement of operational powerup 3300. Prior to the operation of attaching a commissioned device 3300, the Fieldbus interface is operational. The configuration ofthe Fieldbus interface includes the field device in an attached condition. The physical device tag and the device identification ofthe field device are matched. Following the operation of attaching a commissioned device 3300, the field device has an assigned address.

The field device appears in the "live list" at a temporary address 3302. In a step 3304, the interface queries the field device using a system management identify service (SM-fDENTEFY) and recognizes the field device by the physical device tag and the device identification as part ofthe Fieldbus interface configuration. The set address service (SET-ADDRESS) is called to send the assigned address to the field device 3306, placing the field device in the system management operational state (SM-OPERATIONAL). The field device appears in the "live list" at the assigned address 3308.

Referring to FIGURE 34, a flow chart illusttates a fifth operation or "use case" which describes an operation of replacing a device 3400. A device is replaced by decommissioning the cuπent field device 3402 connected to the process conttol system network link, if possible, and commissiomng a replacement to the UNBOUND device 3404. The step of decommissioning the cuπent field device 3402 is described in detail with reference to FIGURE 32. The step of commissioning a replacement to the UNBOUND device 3404 is described with reference to FIGURE 31.

Referring to FIGURE 35, a flow chart illusttates a sixth operation or "use case" which describes an operation of attaching an UNRECOGNIZED device 3500. Prior to the operation of attaching a commissioned device 3300, the Fieldbus interface is operational. A field device is attached which has a physical device tag and a device identification that is not configured for the cuπent process conttol system network link. Following the operation of attaching an UNRECOGNIZED device 3500, the field device is identified and the software engineering tool displays the device as n UNRECOGNIZED device. The operation of attaching an UNRECOGNIZED device 3500 may be performed without use ofthe software engineering tool. The field device appears in the "live list" 3502. In a step 3504, the interface queries the field device using a system management identify service (SM-EDENTEFY) and determines that the physical device tag and the device identification do not match a field device in the present configuration.

Referring to FIGURE 36, a flow chart illusttates a seventh operation or "use case" which describes an operation of decommissioning an unrecognized device 3600. Prior to the operation of decommissioning an unrecognized device, the Fieldbus interface is operational. The field device is identified which has a physical device tag and a device identification that are not configured for the present process conttol system network link. A software engineering tool displays the field device as an UNRECOGNIZED device.

The operation of decommissioning an unrecognized device 3600 results in a condition in which the physical device tag ofthe field device is cleared and the field device is prepared to be removed from the process conttol system network link. The software engineering tool displays the field device as an OFFLINE device.

The operation of decommissioning an unrecognized device 3600 begins when a user selects a "Decommission" operation for the field device 3602. A graphic user interface includes a software engineering tool that issues a "Decommission" command to an appropriate conttoller within the process conttol system. The decommission command specifies a target I/O subsystem, card and port identifiers, and the device identification ofthe field device to be decommissioned.

If the field device is in the UNITIALIZED state, logic step 3604 directs the decommissioning operation 3600 to a clear the physical device tag step 3612. Otherwise, the interface changes the state ofthe field device 3606 to the INITIALIZED state using a clear address service (CLEAR-ADDRESS). The field device appears in the "live list" at a temporary address 3608.

In a step 3610, the interface queries the field device using a system management identify service (SM-LDENTEFY) and recognizes the field device by the physical device tag and the device identification. The interface uses the set physical device tag service (SET-PD-TAG) to clear the physical device tag 3612, thereby changing the field device state to the UNINITIALIZED state. In a next step 3614, the software engineering tool displays the field device as an OFFLINE device.

A network interface card stores a designation that the field device has been decommissioned 3616 and does not move the field device to a STANDBY address unless directed by the user. If the decommissioned device is not move to a STANDBY address, the interface card tracks the field device until the field device advances off the live list.

Referring to FIGURE 37, a flow chart illustrates an eighth operation or "use case" which describes an operation of placing a decommissioned device in a standby condition 3700. Prior to the operation of placing a decommissioned device in a standby condition 3700, the Fieldbus interface is operational. A field device is decommissioned and in the OFFLENE state.

The operation of placing a decommissioned device in standby 3700 results in a condition in which the field device is placed at a standby address with the physical device tag ofthe field device set identical to the device identification. The software engineering tool displays the field device as a STANDBY device.

The operation of placing a decommissioned device in standby 3700 begins when a user selects a "Place in Standby" operation for the field device 3702. A graphic user interface includes a software engineering tool that issues a "Place in Standby" command to an appropriate conttoller within the process conttol system 3704. The decommission command specifies a target I/O subsystem, card and port identifiers, and the device identification ofthe field device to be placed in standby.

The interface allocates a standby address 3706 for the field device. The set physical device tag service (SET-PD-TAG) is then used to set the physical device tag identical to the device identification 3708, changing the field device state to the ENIΗALIZED state. The set address service (SET-ADDRESS) is called to send the standby address to the field device 3710, placing the field device in the system management operational state (SM-OPERATIONAL). The field device appears in the "live list" at the standby address

3712. Device revision information is read from the resource block 3714. In step 3716, an executing software engineering tool displays the field device as a STANDBY device.

A user may subsequently commission the field device 3718, either by creating a new device or binding the field device to an UNBOUND device in the process conttol system network database. The techniques for commissioning a device are described with respect to FIGURES 30 and 31.

Referring to FIGURE 38, a schematic block diagram illusttates a program structure of a process conttol configuration program for defining a process configuration using a plurality of conttol languages. The module editor 3820 is a software program that executes on the CPU 116 within a workstation such as the engineering workstation 106. Using the module editor 3820, a user activates one language editor of multiple conttol language editors including an attribute editor program 3830, a Function Block Edit/View/Debug program 3840, a Sequential Function Chart program 3850, a Ladder Logic program 3870 and a Structured Text program 3890. The multiple conttol language editors operate with compatible databases and interfaces so that a common control strategy is defined using the different conttol language editors. The look and feel ofthe different conttol language editors is similar so that a user easily and efficiently may use different editors for different puφoses to best take advantage of different aspects of the languages.

The module editor 3820 is the fundamental routine for configuration entry and is used to create, edit, and re-use control and equipment module instances and library modules defined by the SP88 standard. The module editor 3820 supplies a graphical technique for configuring, visualizing, and navigating multiple modules that combine to form a conttol sttategy. The module editor 3820 is also used for module linking and defining module containment.

The module editor 3820 supplies access to all aspects of configuration of a module including support for algorithm definition, as well as information gathering relating to alarms, events, history, condition, help, components and attributes.

The module editor 3820 includes various features that facilitate navigation through a conttol system. For example, the module editor 3820 filters attributes on user-defined key words to supply a focused attribute configuration view. Furthermore, the module editor 3820 includes a fast install capability which defaults to performing the install to all devices affected by changes to the module. The conttol sttategy is transfeπed from the editors into runtime engines using an install script. A plurality of conttol language execution engines execute the conttol strategy on one or more controller/ multiplexers 110.

Off-line configuration supports 'work in progress' for an existing module's conttol sttategy. When the new sttategy is complete, it can be installed to the existing module. This 'work in progress' can be flagged to not allow it to be installed.

The attribute editor program 3830 is a conttol program operated by a user to view and edit parameter values associated with a conttol module or conttol algorithm elements including function blocks, ladders, composites, and the like. The attribute editor program 3830 is used on-line to configure a conttol module. On-line, the attribute editor program 3830 is used to view and edit data. Attributes are defined to furnish module-level access to parameters contained within a module. The attribute editor program 3830 is activated by the module editor 3820 and other conttol language editors. The attribute editor program 3830 presents a simple attribute configuration view using a graphical navigation tree pathway display to consolidate the parameters to be configured for a module. A user activates the attribute editor program 3830 and navigates through the graphical navigation tree to find a particular attribute. When an attribute is selected, the attribute is displayed either using an application window or as a dialog depending on the context from which the display is evoked. The attribute editor program 3830 facilitates configuration by supporting copy, paste and bulk change of attributes using a drag and drop technique. The attribute editor program 3830 is used to define attribute parameter values but not to install attributes since attributes are installed when the module containing the attribute is installed. As attribute parameter values are entered by a user, the attribute editor program 3830 performs eπor checking. The attribute editor program 3830 allows a user to sort and view data with typical spreadsheet capabilities, including expansion and reduction ofthe number of columns, or by containment.

The Function Block Edit/View/Debug program 3840 is a control program operated by a user to define a conttol sttategy by assembling function block elements designated under the Fieldbus Foundation and EEC 1131-3 standards. The function block program 3840 is implemented in a function block execution engine which operates in a controller/ multiplexer 110. The function block execution engine executes function block conttol algorithms using a Function Block Library 3842. The function block program 3840 supplies a graphical editor for creating, editing and reusing conttol strategies using function blocks stored within a Function Block Library 3802 and other defined conttol modules, for example conttol modules defined for usage by other application programs. A created conttol sttategy is saved as a reusable library component in the Function Block Library 3802 for subsequent usage or for usage by another application program. The function block program 3840 also creates, edits and reuses conttol structures for HART and FF timing field devices. The function block and module constituents of a conttol sttategy are not confined to a particular device, but are rather partitioned across multiple conttol devices, including HART and FF timing field devices.

A function block or module includes attributes that are modified using the function block program

3840. Any attribute in the system, unless security protected, is accessed through the navigation tree pathway for that attribute and is read or written from the function block editor.

The function block editor program 3840 supports an off-line creation and debug function for conttol strategies of modules and reusable library components. During off-line operation, a control device is not connected to the network. Offline operation is useful for initializing attributes and parameters before the control device is connected using an attribute editor 3842 ofthe function block editor program 3840 since, during off-line operation, multiple conttol strategies can be open, and configurations can be copied and pasted between strategies.

The function block editor program 3840 also supports on-line graphical editing, viewing and debugging of functions blocks during operation, including display of block input and output values. Selective on-line edit and debug mode options include single step, forced inputs and breakpoint options, for example. One window is used for on-line editing and debugging so that the user may coπect an inconsistent parameter value in place. Input values during on-line editing are checked for consistency with off-line editing values, and disallowed if inconsistent.

Hardcopy output information generated by the function block editor program 3840 includes graphical representation and configuration information such as block attribute and parameter values.

Several features ofthe function block program 3840 facilitate user support including the creation of reusable library components, user conversation support, and input eπor checking. User conversation support within step actions allows a user to configure pop-up dialogs with responses. Reusable library components are developed to simplify engineering during configuration and execution so that a single Function Block Diagram (FBD) acts as a subroutine for multiple modules or FBDs during execution.

The Sequential Function Chart (SFC) Edit/View/Debug program 3850 is a conttol program operated by a user to define a conttol sttategy by assembling steps, step actions and transitions designated under IEC 1131-3 standards. The sequential function chart program 3850 is implemented in an SFC execution engine which operates in a controller/ multiplexer 110. The SFC execution engine executes sequential function chart conttol algorithms including steps, actions and transitions. The sequential function chart program 3850 supplies a graphical editor for creating, editing and reusing sequential conttol strategies using sequential function charts. The sequential function chart program 3850 supports execution of parallel logic paths. Executing sequential function charts are associated with a module, at least for the duration of SFC execution.

A sequential function chart includes attributes that are modified using the sequential function chart program 3850. Any attribute in the system, unless security protected, is accessed from a step in a sequential function chart execution.

The sequential function chart program 3850 supports an off-line creation and debug function for control strategies of modules. During off-line operation, a conttol device is not connected to the network. Offline operation is useful for initializing attributes and parameters before the conttol device is connected using an attribute editor 3842 ofthe sequential function chart program 3850 since, during off-line operation, multiple conttol strategies can be open, and configurations can be copied and pasted between strategies.

The sequential function chart editor program 3850 also supports on-line graphical editing, viewing and debugging of sequential function charts during operation, including a "live" display of attribute values. Selective on-line edit and debug mode options include single step, forced inputs and breakpoint options, for example. On-line editing includes setting of a breakpoint for executing a control sttategy while changes are made in the sttategy. One window is used for on-line editing and debugging so that the user may coπect an inconsistent parameter value in place. Input values during on-line editing are checked for consistency with off-line editing values, and disallowed if inconsistent. The sequential function chart program 3850 supports runtime view including a display of steps, actions, cuπently-executing transactions and attribute values.

Hardcopy output information generated by the sequential function chart program 3850 includes graphical representation and configuration information such as step actions.

Several features ofthe sequential function chart program 3850 facilitate user support including the creation of reusable library components, user conversation support, and input eπor checking. User conversation support within step actions allows a user to configure pop-up dialogs with responses. Reusable library components are developed to simplify engineering during configuration and execution so that a single Sequential Function Chart (SFC) acts as a subroutine for multiple modules or SFCs during execution.

The Ladder Logic program 3870 is a conttol program operated by a user to define a conttol sttategy using ladder elements and function blocks in combination in a ladder logic diagram. The ladder logic program 3870 is implemented in a Ladder Logic engine which operates in a controller/ multiplexer 110. The ladder logic engine executes ladder conttol algorithms including coils, contacts, and several standard function blocks. The Ladder Logic program 3870 includes a basic discrete conttol ladder logic library 3872 which includes the components for solving basic discrete conttol operations. These operations are logical extensions of EEC 1131-3 standards including elements such as coils, contacts, timers, flip/flops, edge triggers and counters with one output connection defined per ladder rung. The Ladder Logic program 3870 also supports placement of user-defined blocks within a ladder logic diagram. A ladder logic diagram is applicable to a function block that supports power flow in which the state of execution is determined by whether "power" is flowing through a "rung" in the ladder. Power flow is somewhat analogous to data flow in a logic diagram. The applicable function blocks, alone, are displayed by the Ladder Logic program 3870 on a ladder logic palette.

The Ladder Logic program 3870 may be exclusively used by a user to configure and debug a control strategy or a ladder diagram sheet may be used as a composite within another ladder logic sheet, a function block diagram sheet or an sequential function chart sheet. A ladder logic sheet can hold composite ladder logic diagrams, function block diagrams or sequential function chart sheets. A ladder logic element can read and write to attributes in other sheets and in other modules.

Ladder logic diagrams support both on-line and off-line editing. User can switch from debug functionality to the edit mode on a specific ladder logic diagram to make structural changes in the conttol sttategy. The user may change any parameter from either the debug view or the edit view.

The Ladder Logic program 3870 includes a debug functionality that includes a display of power flow, parameter values and energized or de-energized states. The ladder logic debug functionality is the substantially the same as the debug functionality ofthe Sequential Function Chart editor program 3850 in which the user forces input values, sets breakpoints and the like. The Ladder Logic program 3870 supports ladder logic simulation, historical data collection and mode, alarm and status report generation.

Referring to FIGURE 39 A, a screen presentation of a configuration screen 3900 is depicted which is generated by a configuration program using the function block editor 3840. The configuration screen 3900 includes a navigation portion 3902 and a screen-specific portion 3904. The navigation portion 3902 includes navigation tabs 3910 which allow a user to access particular sections ofthe configuration program. In the illustrative state ofthe configuration screen 3900, the configuration program is awaiting a user entry of a configuration command. Navigation tabs 3910 indicate several primitive functions for the entry into a function block including a navigation tab 3912 for selecting a simple set dominant (SR) flip-flop, a navigation tab 3914 for selecting a simple subtract block, a navigation tab 3916 for selecting a simple timed pulse block, a navigation tab 3918 for selecting a simple ttansfer block, and a navigation tab 3920 for selecting a simple exclusive-OR (XOR) block. The navigation tabs 3910 also include a block assistant 3922 tab for inserting a function block . The screen-specific portion 3904 illustrates a function block 3924 that is to be configured, including configuration of attributes and connections with other function blocks.

The block assistant 3922 tab is selected to insert a function block. Referring to FIGURE 39B, a Selection screen 3930 is displayed in response to the selection ofan insert function block. The selection screen 3930 also includes a selection portion 3932 and a screen-specific portion 3934. The screen-specific portion 3934 includes an entry block 3936 for entering the name of a new block that is to be created. The selection portion 3932 includes a plurality of selection tabs 3938 including a function block 3940 tab, an embedded block 3942 tab, a linked composite 3944 tab and a module block 3946 tab. The selection portion 3932 also includes a variety of buttons which furnish navigation functions, including a Back button 3948, a Next button 3950 and a Cancel button 3952. The Back button 3948 takes the user to the previous screen presentation in strict historical order. The Next button 3950 takes the user to the screen presentation appropriate for the selections that are made on the cuπent screen presentation. The cancel button 3952 terminates the selection.

The embedded block 3942 tab is selected to insert an embedded block.

Referring to FIGURE 39C, a Choice screen 3960 is evoked to allow the user to select a conttol language editor for configuring the embedded block, either a function block editor using selection 3962 or a sequential function chart editor using selection 3964.

The selection 3964 is chosen to utilize the sequential function chart editor.

Referring to FIGURE 39D, a screen presentation of a configuration screen 3970 is illusttated in which the function block 3924 is configured using the function editor 3840 and a newly created block 3972 is configured using the sequential function chart editor 3850.

Editing of newly created block 3972 is selected so that the sequential function chart editor 3850 is invoked.

Referring to FIGURE 39E, details of a the newly created block 3972 are shown in the screen- specific portion 3934 ofthe configuration screen 3980 including attributes 3982 and a step 3984. The navigation portion 3986 ofthe configuration screen 3970 no longer lists navigation tabs relating to function blocks, but rather includes navigation tabs 3988 relating to a step 3990, a ttansition 3992, a termination 3994, and input terminal 3996 and an output terminal 3998 to define the steps and ttansitions of a sequential function.

Referring to FIGURE 40, an object model shows object relationships of various objects for handling alarm and event functions. Various conditions are defined to be "events" including Alarms, Alarm acknowledgments, user changes (writing attributes, invoking methods, log-in/out), configuration changes to the "run-time" system (installations, de-installs, etc.), Sequential Function Chart (SFC) state changes,

Operator Attention Requests (OARs), and other miscellaneous Events (non-alarm state ttansitions including equipment state changes). A common characteristic for all types of events is that the occurrence or state transition of an event can be recorded in a Event Journal. All events are associated with one (or more) plant areas. Event occurrence records (RtEventOccuπenceRecord 4040) are captured in the Event Journal, or Journals, (RtEventJournal 4020) designated for the associated plant area (RtPlantArea 4010).

A user activates the Event Journal, typically using a workstation, by configuring one or more Plant

Areas within which the activated Event Journal captures events. On-line operation ofthe Event Journal is modified under user conttol by disabling or enabling specified classes of events to be recorded.

The user configures an Alarm behavior by creating Alarm Atributes (RtAttribute 4032) in Conttol Modules or Equipment Modules (RtModule 4030). An Alarm Attribute furnishes reference to any boolean Attribute within the Control Module or Equipment Module containing the Attribute. Alarm Attributes are created only at the Module level. Alarm Attributes are not created in Composite Function Blocks.

Referring to FIGURE 41, a state ttansition diagram illusttates alarm attribute states. A user either disables or enables an Alarm Attribute. When disabled 4110, the Alarm Attribute appears in a "normal" condition, called an "Inactive and Acknowledged" condition. The Disabled/Enabled condition of an Alarm Attribute is changed either on-line, by an Operator, or automatically by a control algorithm in the system.

The initial Disabled/Enabled condition is set at configuration time. An enabled Alarm Attribute has either an Active condition 4116 or 4118 or an Inactive condition 4112 or 4114. The Alarm is Active ( "in alarm") when the referenced boolean Attribute is TRUE. The Alarm Attribute is optionally configured to invert the sense ofthe alarm state, so an Alarm Attribute with .INV characteristic TRUE operates is if the referenced Attribute's value of FALSE indicates an "in alarm" condition. The Active/Inactive condition is driven by the state ofthe referenced Attribute so that the Active/Inactive condition is not directly changed by the Operator or another control algorithm.

While Enabled, an Alarm Attribute has either an Acknowledged 4112 or 4116 or Unacknowledged state 4114 or 4118. The Alarm Attiibute is placed in the Unacknowledged condition only if the Alarm Attribute makes a transition from Inactive to Active state, unless automatically acknowledged. An Operator or another conttol algorithm may acknowledge the Alarm, changing the Alarm Attribute to the Acknowledged condition.

An Alarm Attribute is either automatically acknowledged (AACK'd) or not automatically acknowledged. AACK is determined from the cuπent Alarm priority. A user-configured, system-wide table determines AACK behavior. For example, the table may designate that all "LOW priority Alarms are automatcally acknowledged (AACK is TRUE), all "MEDIUM" and "HIGH" priority Alarms are not automatically acknowledged (AACK is FALSE). When AACK is TRUE, the alarm is never placed in an Unacknowledged condition. The combined operation ofthe Enable/Disabled, Active/Inactive, and Acknowledged/Unacknowledged conditions results in user-visible states for an Alarm Attπbute that are shown in FIGURE 41.

An enabled Alarm Attribute initially goes to the Inactive/Ack'd State 4112, and may immediately ttansition to either Active/Unack'd 4114 or Active/ Ack'd 4116. The ttansition to Active/Ack'd 4116 is accompanied by a standard "ttansition" behavior for Alarms in which the transition is timestamped and the event is recorded in the event journal, for example.

The Alarm Attribute has multiple fields that provide a user-visible interface. A CUALM "cuπent alarm" field is "OK" when the Alarm Attribute is in the Disabled state 4110, the Inactive/Ack'd state 4112 or Inactive/Unack'd state 4114. Otherwise CUALM is the word/value associated with the configured Alarm Type. A DESC "descπption" field has an alarm description that is generated when the Alarm Attribute changes state. The DESC field is initialized to the empty stπng. A LAALM "latched alarm" field is "OK" when the Alarm Attribute is m the Disabled state 4110 or the Inactive/Ack'd state 4112. Otherwise the LAALM field is the word value associated with the configured Alarm Type. The LAALM field presents "latched" alarm activations, enabling Acknowledgment even if the duration of being Active is very short. A NALM "unacknowledged alarm" field indicates the Acknowledged/Unacknowledged condition ofthe Alarm Attribute. The NALM field is used to determine when alarm summary entries can be removed. An ENAB "alarm enabled" field indicates the cuπent Enabled condition for the Alarm Attribute. An EENAB "alarm initially enabled" field indicates the configured Enabled condition for the Alarm Attribute. An INV "inverted input" field indicates whether the value of an associated boolean Attribute is inverted before alarm processing The INV configurable characteristic permits an Alarm Attπbute reference normally TRUE boolean Attπbutes, for example an Attribute holding a discrete input A PRI "alarm priority" field indicates cuπent prioπty (High/Medium/Low) of an Alarm Attribute. TABLE II shows the boolean Attπbutes as follows:

The process conttol system 100 consolidates many potential Active Alarm conditions into a short list of "highest priority" alarms. A selection criteria is used to select the highest priority alarms for consolidation. The selection criteria includes analysis, in order of decreasing preference, the Acknowledged condition with the Unacknowledged condition having precedence over the Acknowledged condition, the Alarm Priority in order of High then Medium then Low precedence, and the Time of Detection with the newest timestamp gaining precedence.

Alarm Consolidation is available at the SP88 Module level and the Plant Area level. Alarm consolidation is accessed via a pre-defined Attribute name "ALARMS" available on SP88 Modules (Conttol & Equipment) and Plant Areas. ALARMS is an indexed Attribute, where the index selects the Nth highest priority alarm in the consolidation (e.g. ALARMS[1] accesses the highest priority Alarm, ALARMS[2] accesses the second highest priority Alarm, etc.) Thus, for example, 'AREA1/FIC101/ALARMS[1]' references the highest priority Alarm in Module FIC101 and 'AREA1/ALARMS[2]' references the second highest priority Alarm in Plant Area AREAl . The maximum index supported on the ALARMS Attribute is 5.

The Fields supported on the ALARMS [N] Attribute include the LAALM "latched alarm" field which indicates the Active Or Unacknowledged conditions ofthe Nth priority Alarm Attribute. The LAALM Field is in the alarm word, or alarm type value, of the Nth priority Alarm Attribute during the ACTIVE/UNACK'D, ACTIVE/ACK'D, or ENACΗVE/UNACK'D states. The NALM "unacknowledged alarm" field indicates the Acknowledged/Unacknowledged condition ofthe Nth priority Alarm Attribute. The PRI "alarm priority" field indicates the configured priority (High/Medium/Low) ofthe Nth priority Alarm Attribute. A TAG "alarm Tag" field returns a fully qualified Attribute reference string (excluding Field) for the Nth priority Alarm Attribute. A MODULE "alarm Module" field indicates the SP88 Module (tag) which has the Nth priority Alarm. The MODULE tag returns a Module reference string which can be used to access the "primary conttol display" attribute for that Module. Some Fields are supported on the ALARMS Attπbute only at the SP88 Module level. If an index value is applied for these fields, the index value is ignored. The SP88 Module level ALARMS Attπbute fields include an ENAB "alarm enabled" field which indicates the cuπent Alarm Enabled condition for the Module. A PRIAD "prioπty adjustment" field is a number (normally 0) which is added to the cuπent Priority of each Alarm Attribute in the Module when determining the effective Priority of an Alarm The PRIAD Module-wide adjustment is used to decrease the Alarm Priorities of all the alarms in a Module, permitting diminished Alarm visibility. TABLE III descπbes the ALARMS Attπbute, in detail, as follows

User-Level Alarm Consolidation is achieved using an "Alarm Banner" in the graphical user interface. Alarm consolidation is supported for a "cuπent user". Each user is granted authority over one or more Plant Areas. The "cuπent user" alarm consolidation provides the ability to present the highest prioπty alarms ofthe set of Plant Areas cuπently in the user's span of conttol. A pre-defined "attπbute container" exists, named "THISUSER", which supports the ALARMS [N] Attribute. Users optionally construct displays referencing 'TIIISUSER/ALARMS[N] field' to allow quick access to the highest priority alarms for the "cuπent user".

A user Enables and Disables Alarms if granted an alarm privilege With the alarm privilege, a user may Enable or Disable a single Alarm Attribute by writing to the .ENAB field (e g. writing TRUE to 'AREAl/FIClOl/HJALM ENAB'. Each Alarm Attribute in the process control system includes a single Enable/Disable condition. When one user changes state, Alarms are Enabled/Disabled for all users With the alarm privilege, a user may Enable or Disable all alarms in a SP88 Module Alarm by writing to the .ENAB field ofthe ALARMS Attribute (e.g. writing TRUE to 'AREAl/FIClOl/ALARMS.ENAB'). Disabling Alarms at the Module level overrides, but does not overwrite, individual Alarm's .ENAB condition. When Alarms are Enabled at the Module level, Alarm processing determined by the individual Alarm's .ENAB condition is restored.

Each SP88 Module in the system includes a single Enable/Disable condition. When one user changes state, all Alarms in that Module are Enabled Disabled for all users.

A user having an operate privilege can Acknowledge Alarms. With the operate privilege, a user Acknowledges a single Alarm Attribute by writing FALSE to the .NALM field (e.g. writing FALSE to 'AREA1/FIC101/HIALM.NALM'). Attempts to write TRUE to the .NALM are ignored. Each Alarm

Attribute in the process conttol system has a single Acknowledge condition. When one user changes state, Alarms are Acknowledged for all users. With the operate privilege, a user may Acknowledge all alarms in a SP88 Module Alarm by writing FALSE to the .NALM field ofthe ALARMS Attribute (e.g. writing FALSE to 'AREAl/FIClOl/ALARMS.NALM'), an operation which has substantially the same effect as writing FALSE to the .NALM field of all Alarm Attributes in the Module. Attempts to write TRUE to the .NALM are ignored.

A user having an alarm privilege can change alarm priority. With the alarm privilege, a user may change PRI on a single Alarm Attribute by writing to the .PRI field (e.g. writing 0 to 'AREAl/FIClOl/HLALM.PRI' to make it a "HIGH" priority alarm). Since Auto Acknowledgment behavior is determined by Alarm Priority, changing Alarm Priority may cause an Alarm to change acknowledgment status. For example, changing from a priority with AutoAck FALSE to a priority with AutoAck TRUE should cause unacknowledged alarms to be acknowledge. Also, changing from a priority with AutoAck TRUE to a priority with AutoAck FALSE should cause acknowledged alarms to become unacknowledged.

Each Alarm Attribute in the system has a single .PRI condition. When one user changes state, .PRI is changed for all users.

With the alarm privilege, a user may adjust the effective priority for all alarms in a SP88 Module Alarm by writing to the .PRIAD field ofthe ALARMS Attribute. For example, a user writing 1 to 'AREAl/FIClOl/ALARMS.PRIAD' increases the cuπent Alarm Priority value, thereby diminishing the annuciation behavior, by one "step" so that HIGH priority becomes MEDIUM priority, and LOW priority becomes LOG. The user only sets PRIAD to positive numbers and therefore is only used to diminish normal annunciation behavior. Setting PRIAD to 0 reestablishes the "normal" priorities determined per Alarm Attribute. Effective alarm priorities are not adjusted "below" LOG. Since Auto Acknowledgment behavior is determined by Alarm Priority, changing PRIAD at the Module level may cause individual Alarms to change acknowledgment status. Each SP88 Module in the system has a single .PRIAD value. When one user changes state, all Alarms in that Module are affected for all users.

Alarms are viewed using a display under a standard FIX™ Alarm Summary. The FIX™ graphic and display program, which is marketed by Intellution of Norwood, MA, is well known in the computing arts. The FIX™ Alarm Summary Link is the primary method to view filtered and sorted lists of Active Alarms. All capabilities ofthe Alarm Summary Link are supported, with the following exceptions or extensions. First, a "Tagname" column shows the process conttol system Attribute reference path, excluding the Field name, for the Alarm Attribute (e.g. 'AREAl/FIClOl/HJALRM'). Second, a "Description" contains a user-configured string that is constructed at the time the Alarm is detected so that an Alarm captures the value of up to two Attributes at the point the Alarm was first detected. Only one "Alarm" per "Tag" is possible so that multiple Alarms may be shown for each SP88 Module in the Alarm Summary. Third, a "Time Last" entry contains the time ofthe last state ttansition for the Active Alarm, which could be the time of acknowledgement, or the time ofthe last ttansition between Active/Inactive for an unacknowledged alarm. Fourth, a "Node" column entry, which shows FIX SCADA Node source for the Alarm, is meaningless for process conttol system Alarms so that a by Area Filter and Sort feature are lost. Fifth, all Alarms are mapped into one ofthe FEX Alarm types to achieve foreground color based on the Alarm Type.

A user can access an Alarm State Transition Journaling record. Alarm state transitions are recorded in the Event Journal assigned to a Plant Area. All alarm state ttansitions shown in FIGURE 41 are recorded in the Event Journal, including ttansitions between the Inactive/Unack'd 4114 and the Active/Unack'd state 4118. Thus an operator viewing the LAALM field in displays or alarm summaries does not see ttansitions between Active/Inactive states for unacknowledged alarms, these ttansitions are recorded in the Event Journal.

Event journal entries for alarm state ttansitions include: (1) a timestamp ofthe alarm state ttansition as determined by the device (e.g. conttoller) detecting the alarm condition, (2) an "alarm" event type which distinguishes from other event journal entries, (3) a user-defined alarm category, (4) a current alarm priority, (5) an alarm word string as configured in the system Alarm Type table, (6) an new alarm state, (7) an attribute reference string or path for the alarmed attribute, and (8) a description string assembled from the description string configured in the Alarm Type table, with the configured (up to two) Attribute values inserted in the string.

A Event Journal browser application presents data in a manner shown in TABLE IV, generally sorted by timestamp and filtered on event type = "ALARM" and attribute reference string = "FIC101/PID1/HIALM'):

TABLE IV

Alarm state transitions events in the Event Journal are distinct from operator change journal entries, although operator changes cause coπesponding alarm state changes. For example, as shown in TABLE V as follows:

TABLE V

The Alarm Attributes are configured, thereby setting the Alarm behavior and presentation, using the described sequence of operations. First, an "Alarm Types" Table and an "Alarm Annunciation" Table are configured. Second, in an optional step, the user-defined alarm conditions are configured, setting the boolean Attributes. Third, Alarm Attributes are created to reference the boolean Attributes, thereby identifying the System "Alarm Type", priority, and the like. Fourth, Module "instances" are created based on Module Definitions that contain Alarms. Fifth, a presentation of Alarm information is inserted into displays (pictures) via database links, dynamic color links, and Alarm Summary links. Sixth, the "Alarm Types" and "Alarm Annunciation" Tables are configured.

The "Alarm Type" table has several functions, including (1) acting as a system (Site) wide common resource which defines a common Alarm presentation behavior to speed the Alarm configuration process for each Alarm, (2) encouraging standard alarm messaging in Summaries and History Journals to improve query and analysis that information, (3) mapping alarms into FIX Alarm States.

The "Alarm Types" Table contains columns including an Alarm Type, an Alarm Word, a category and a description string column. The Alarm Type column contains a brief description ofthe Alarm Type, which is used to select the appropriate Type when creating an Alarm Attribute. The Alarm Word column includes a string that is returned when reading the A CUALM or A LAALM Fields when the Alarm is Active. The category column describes a user defined word recorded in the Event Journal used to help filter/sort queπes The descπption stπng appears in the Alarm Summary Link and contains up to two place holders for Attπbute value substitution at Alarm Detection time

The "Alarm Types" Table default content is shown in TABLE VI as follows

TABLE VI

Standard alarm types match the alarms types supported in FIX™

The "Alarm Annunciation" table is a system (Site) wide common resource which furnishes a common definition of Alarm annunciation behavior to speed the Alarm configuration process for each Alarm

The "Alarm Types" Table contains the columns including an Alarm Pπoπty, an Auto Acknowledgement, a WAV file and a PC speaker frequency column The Alarm Pπoπty designates the

Alaπn pπoπty word (fflGH/MEDIUM/LOW/LOG) The Auto Acknowledgment column contains a YES/NO

^! Probably no reason for this to be configured, or even visible to the user value indicating if alarms of this priority should be automatically acknowledged when detected andproviding an opportunity to make less important alarms less "distracting". The WAV file contains a filename of a NT compatible .WAV file which is played (looping) when an Alarm is detected (withm the scope ofthe cuπent user) at a Workstation with a sound card Omitting this file name indicates that no .WAV file should be played for alarms with this priority. The PC Speaker frequency sets a value used to play a tone on the PC speaker when an Alarm is detected, within the scope ofthe cuπent user, at a Workstation without a sound card. A value of 0 indicates that the PC speaker should not be used for alarms with this pπoπty. Ef a .WAV file and a non 0 speaker frequency are specified for the same alarm priority, the PC speaker is used only if no sound card is present.

The "Alarm Annunciation" Table default content is shown in TABLE VII as follows:

A user attaches Alarm (behavior) to boolean Attributes by creating Alarm Attributes according to the SP88 Module Definition which reference another boolean Attπbute in the same Module.

A user create an Alarm Attribute by enteπng: (1) a target Attπbute by path or by drag-and-drop, for example, (2) a boolean Attribute defining the alarm condition, (3) an Alaπn Type selected from the system- wide list of Alarm Types, (4) an Alarm Pπoπty (High Medium/Low/Log), (5) an Initial Alarm Enable condition (YES/NO), (6) an Invert Input (YES/NO), (7) an optional Name of Attribute having a value to be substituted for %P1, (8) an optional Name of Attπbute having a value to be substituted for %P2.

Items 7 & 8, the Attribute names, are restricted to Attπbutes in the same SP88 Module and are specified as "module relative" attribute references (e.g. "SP" and "PEDl/PV" rather than "FIC101/SP" or "FIClOl/PIDl/PV".

The user also creates Module "instances" based on Module Definitions that contain Alarms. When a Module instance is created, all Alarm behavior specified in the Module Definition applies to the Module instance. The .PRI and .ENAB fields may be overridden on Alarm'd Attπbutes when the Module instance is created. For example, if for an Alarm Attribute named 'fflGHLIMETED', PRE is MEDIUM when the Module Definition is constructed, then when the Module instance is created, 'HIGHLIMITED.PRI' may be overridden to be LOW for this instance

Alarms are supported for Device/Subsystem Attributes in Conttollers. Attributes are defined for devices and device subsystems to provide access to information about the operation ofthe conttol system and connections to other systems. The Attπbutes are accessible via diagnostic tools and via pre-defined or user- __ηη

defined displays. It is valuable for some of these Attributes, especially "consolidation" Attributes, to participate in the Alarm system to draw attention to abnormal conditions in the conttol system.

Users create Conttol Modules (instances) to implement a desired "Device Alarm" strategy for Conttollers and Subsystems, including processor, communications, I/O, redundancy, and the like.

Using Function Block algorithms, the Device/Subsystem Attributes are accessed most efficiently in the same device, but also supported for other Conttollers and Workstations. Device and Subsystem Attributes are used as inputs to Function Blocks, which then can be configured to applying alarm limits on these Attributes, converting these values to boolean Attributes. AlarmAttributes then reference the boolean Attributes. In general, the full algorithm definition capability ofthe Function Block system is used to build simple or complex Device Alarming schemes.

A number ofthe pre-defined Alarm Types, which are consistent with FIX™ alarm types, are suitable for distinguishing "Device Alarm" presentation and behavior. Pre-defined Conttol Module Definitions are supplied providing fairly comprehensive Device Alarm "modules" for Conttollers, and each type of I/O system. Users optionally disable or extend these standard modules.

Users may elect several strategies for placing Device Alarm modules in Plant Areas including a small-system sttategy, a "segregation" sttategy and a"partitioned responsibility" sttategy, for example. In the small system an "all in one" sttategy is imposed in which the Plant Area concept is not applied. One or more Device Alarm Modules in each Conttoller form an integrated presentation of Device and SP88 Module alarms. In the segregation strategy a separate Plant Area is designated which has all Device Alarm modules from all Conttollers. The segregation sttategy enables Area filtering/sorting on Alarm summaries, allowing Operators to focus on SP88 Module Alarms and Process/Maintenance Engineers to focus on Device Alarms. The partitioned responsibility sttategy is used when the system becomes large enough to control scope of responsibility by Plant Area. Device Alarm Modules are placed in the same Plant Area as the SP88 modules impacted by the Device Alarm Modules. The partitioned responsibility sttategy forms an integrated presentation of Device and SP88 Module alarms for Plant Areas within scope of responsibility.

Alarms are supported for Device/Subsystem Attributes in Workstations. User-initiated applications such as Draw, View, engineering tools, and the like individually present information about abnormal conditions or eπors encountered, in the appropriate context. Workstation Services which are activated on a workstation before a user logs on and continue to run through log-off/log-on cycles) implement a technique for drawing attention to problems, even for an unattended Workstation. In one embodiment, Workstation Services are monitored by Device Alarm Modules executing in one or more Conttollers. The Services construct a set of status and integrity Attributes, which are accessed by Controller(s) running instances of Device Alarm Modules which conttol the user-defined Device Alarming sttategy. Pre-defined Conttol Module Definitions are supplied providing fairly comprehensive Device Alarm "modules" for Workstations, and each major Service (e.g. communications, history journal, etc.) Users may disable or extend these standard modules.

In one embodiment ofthe process conttol system, event conditions that are not afforded "Alarm" status are given a priority of "LOG". LOG Alarms are not consolidated in ALARMS Attributes, do not appear in the Alarm Summary, do not provide audible annunciation of state changes, and appear in Event Journals as type "EVENT" rather than type "ALARM'. In other respects a LOG priority Alarm operates as HIGH/MEDIUM/LOW priority Alarm so that an event (1) is enabled disabled individually, (2) is disabled at the Module level with other alarms, (3) individual Alarms can be "turned into Events" by changing their priority to "LOG" (writing 3 to .PRI).

By setting .PRIAD at the Module level, one or more levels of Alarms can be converted to Events

(e.g. writing 2 to .PRIAD drops all Alaπn priorities in the Module by 2 steps; HIGH priority becomes LOW, MEDIUM and LOW priority become LOG, LOG remains LOG). Setting .PRIAD to 3 forces all Alarms in the Module to become "Events". CUALM, LAALM, NALM field supported to display cuπent status (even blinking if unacked).

LOG events also (4) may invert the input boolean, to reverse the sense ofthe OK event condition for usage to log changes in state of Discrete Inputs, (5) may add user defined "alarm words" to the Alarm Types table to give event conditions useful names, (6) record all state changes for a LOG priority alarm in the Event Journal.

User selectable "intensities" of system event detection (e.g. "debug intensity", "normal intesity", "shutdown intensity") are configured in Conttol Module algorithms based on the setting of a user defined "intensity" Attribute. System Events are thus aligned with one (or perhaps more) Plant Areas, and so enabling the Event Journal on a Workstation for one or more Plant Areas automatically sets the destination for all "System Event'^" records.

A user changing an Attribute or invoking a method on a System Object is considered an event and is recorded in the appropriate Event Journal. Changes to conttol hierarchy (Conttol Module, Equipment Module, Plant Area, etc.) Attributes are recorded in the Event Journal(s) designated for that Plant Area. Changes to Device/Subsystem Attributes are recorded in the Event Journal(s) for the "primary Plant Area" designated for that Device.

Referring to FIGURE 42, a context diagram shows a context for defining an alarm event with respect to a conttol module. An Alarm appears in a "Plant Area scope" active alarm list presentation. A composite module (CM) instance 4210 includes a PID function block 4212, an output attribute 4214 and a high alarm attribute 4216. A user, such as a configuration engineer, selects the composite module 4210 for editing and selects "add alarm" 4220 on Attribute "HEHI". The user also selects the event priority definition named "Advisory" 4232 and the event type definition named "HIALARM" 4234. The user then saves the changes to the control module 4210.

Referring again to FIGURE 40, alarm and event management is described. Alarms and user- defined "events" which are configured as LOG priority Alarms introduce multiple behaviors into the process conttol system.

A special kind of RtAttribute, hereafter called RtAlarmAttribute 4034, has a distinct "data type" supporting Alarm specific fields such as CUALM, NALM, and the like which may be read and written. Read access to the fields allows presentation ofthe state of individual Alarms. Write access to selected fields gives an ability to Acknowledge Alarms, and change certain alarm behaviors.

Several characteristics of Alarm behavior, such as Disabled and AUTOACK behavior, may be overridden on-line at the SP88 Module level. Reverting to the individual Alarm conditions of Enabled/Disabled and NoAutoAck/AutoAck occurs when the Module level overrides are removed. The changing of Module level overrides should "immediately" impact individual Alarm states. Thus changes on the Module level override force re-evaluation of all Alarm states within the module under the new conditions.

Active alarms are consolidated at the Module (RtModule 4030), Plant Area (RtPlantArea 4010), and

User Session so that the "highest priority alarms" at each ofthe levels may be presented. This consolidation is accessed through the ALARMS[] Attribute supported by Module, Plant Area and User Session objects.

FIX™ Alarm Summary Links are used in FIX™ pictures (displays) to present a list of "cuπent" alarms. The content for the Alarm Summary Link is maintained by the ALMSUM.EXE process (which shuts down when FIX™ shuts down, and FIX™ shuts down whenever an NT user logs off³, and NT users log off to allow a new user to "log in".) Thus the system must both "prime" the ALMSUM process with all current alarms (subject to cuπent user responsibility scope) to get it started when an new user logs-on, and it must feed the ALMSUM process information about new alarm occurrences, and alaπn acknowledgments so a up- to-date summary can be presented.

All alarm state ttansitions are directed to the appropriate Event Journal(s) (RtEvenUournal 4020) for the Plant Area which "contains" the RtAlarmAttribute 4034. Multiple Event Journal targets are supported, so that a complete Event Journal can be reconstructed if one workstation running one ofthe Event Journals is offline for a period of time.

Audible annunciation of Alarm entry state ttansitions executes on workstations doing Alarm Summarization (feeding the FIX ALMSUM.EXE process). Audible annunciation may consist of a continuous tone (user configured frequency) on the PC speaker, and/or a continuous (looping) .WAV file played on a compatible sound card installed in the PC. A program is executed to turn off both the speaker and the sound card, thus the sound may be turned off by any FIX™ (view button or keyboard) script, or an ICON in the program Group if FIX VIEW is not running.

Referring to FIGURE 43, an object communication diagram illusttates a method for performing an attribute write operation that evokes an "in alarm" status.

Previous to the attribute write operation, a RtAlarmAttribute has been configured and installed, alarms are ENABLED at both the Attribute and the Module level, alarm AUTOACK is false at both the Attribute and the Module level, and the cuπent Alaπn state is "Inactive/Acknowledged".

The "write Attribute" method causes the state of an Alarm Attribute to go into the alarm state. The alarm fields ofthe Alaπn Attribute are updated to reflect the new Alarm state. An event occuπence record is constructed, and sent to the Module, Plant Area, and workstation applications (Alarm Summary, Event Journal), as needed.

When the attribute write operation is complete, the cuπent Alaπn state is "Active/Unacknowledged", the active alarm has been recorded by the Module, the event occuπence record has been constructed, and has been queued for transmission to devices monitoring this Plant Area in this Device.

In a step 4310 ofthe write attribute method, RtAlarmAttribute receives a writeAttribute, which causes a state ttansition in the boolean Attribute to enter the alarm state. In step 4312, RtAlarmAttribute gets alarmDisable status from the RtModule containing RtAlarmAttribute so that both Attribute and Module Alarm behavior are ENABLED. In step 4314, RtAlarmAttribute gets alarmAutoack status from the RtModule containing RtAlarmAttribute so that for both Attribute and Module Alarm AUTOACK is DISABLED. In step 4316, RtAlarmAttribute computes a new alarm state, the "Active/Unacknowledged" state and reads the prototype event descriptor string from RtEventTypeDefinition using AlarmType as an index. In step 4318, RtAlarmAttribute constructs the descriptionString for the RtEventOccurenceRecord, reading cuπent attribute values from the containing RtModule, if necessary. In step 4320, RtAlarmAttribute constructs a new RtEventOccurenceRecord. Since a new alarm is created,

RtAlarmAttribute tells its containing RtModule to addEventOccurrence in step 4322. In step 4324, RtModule tells its RtActiveAlarmList to addEventOccurrence, adding a new entry to the list and returning a handle by which the entry can be accessed in the future. This handle is ultimately stored by RtAlarmAttribute. In step 4326, RtModule sends the RtEventOccurenceRecord to the RtPlantArea of RtModule via recordEventOccurrence. In step 4328, RtPlantArea tells its RtAreaEventLog to addEvent, RtAreaEventLog sees that at least one workstation client has registered an interest in receiving EventLog records, creates an RtEventLogRecord from the RtEventOccurenceRecord, and queues the RtEventLogRecord, thereby destroying the RtEventOccurenceRecord. -o I-

Also referring to FIGURE 43, the object communication diagram is also applicable to Acknowledgement ofan Alarm, causing the cuπent alaπn state to go to "Active/ Acknowledged". The new alaπn state for the existing alarm is recorded by the Module, a new event occuπence record is constructed, and is been queued for transmission to devices monitoring this Plant Area in this Device. The method includes application ofthe "write Attribute" method (writing FALSE to the NALM Field) to cause the state of an Alarm Attribute to be acknowledged. Alarm fields of the Alarm Attribute are updated to reflect the new Alarm state. An event occurrence record is constructed, and sent to the Module, Plant Area, and workstation applications (Alarm Summary, Event Journal) as needed.

In step 4310, RtAlarmAttribute receives a writeAttribute, causing the NALM Field to change state to FALSE. In step 4312, RtAlarmAttribute gets alarmDisable status from the RtModule containing RtAlarmAttribute so that both Attribute and Module Alarm behavior are ENABLED. In step 4316, RtAlarmAttribute computes a new alarm state, the "Active/Unacknowledged" state and reads the prototype event descriptor string from RtEventTypeDefinition using AlarmType as an index. In step 4318, RtAlarmAttribute constructs the descriptionString for the RtEventOccurenceRecord, reading cuπent attribute values from the containing RtModule, if necessary. In step 4320, RtAlarmAttribute constructs a new RtEventOccurenceRecord. Since an existing alarm is updated, RtAlarmAttribute tells the RtModule containing RtAlarmAttribute to updateEventOccurrence, identifying RtModule by the handle returned when from updateEventOccurrence in step 4322. In step 4324, RtModule tells RtActiveAlarmList to updateEventOccurrence, thereby updating the existing entry in the list. In step 4326, RtModule sends the RtEventOccurenceRecord to the RtPlantArea of RtModule via recordEventOccurrence. In step 4328, RtPlantArea tells its RtAreaEventLog to addEvent, RtAreaEventLog sees that at least one workstation client has registered an interest in receiving EventLog records, creates an RtEventLogRecord from the RtEventOccurenceRecord, and queues the RtEventLogRecord, thereby destroying the RtEventOccurenceRecord.

Also referring to FIGURE 43, the object communication diagram is also applicable to aknowledgement of clearing ofan alarm condition, in which the "write Attribute" method causes the state of an Alarm Attribute to go out ofthe alarm state. The alaπn fields ofthe Alaπn Attribute are updated to reflect the new Alarm state and an event occuπence record is constructed and sent to the Module, Plant Area, and workstation applications (Alarm Summary, Event Journal) as needed. When the write Attribute method is complete, the cuπent Alarm state is "Inactive/Acknowledged". The current alarm information for this alaπn has been removed by the Module. A new event occurrence record has been constructed and queued for transmission to devices monitoring this Plant Area in this Device.

In step 4310, RtAlarmAttribute receives a writeAttribute, which causes a state ttansition in the boolean Attribute to go out ofthe alarm state. In step 4312, RtAlarmAttribute gets alarmDisable status from the RtModule containing RtAlarmAttribute so that both Attribute and Module Alarm behavior are

ENABLED. In step 4316, RtAlarmAttribute computes a new alarm state, the "Active/Unacknowledged" state and reads the prototype event descriptor string from RtEventTypeDefinition using AlarmType as an index. In step 4318, RtAlarmAttribute constructs the descriptionString for the RtEventOccurenceRecord, reading cuπent attribute values from the containing RtModule, if necessary. In step 4320, RtAlarmAttribute constructs a new RtEventOccurenceRecord. Since an existing alarm is cleared, RtAlarmAttribute tells the RtModule containing RtAlarmAttribute to updateEventOccurrence, identifying RtModule by the handle returned when from updateEventOccurrence. In step 4322, RtModule tells RtActiveAlarmList to updateEventOccurrence, thereby updating the existing entry in the list. In step 4326, RtModule sends the RtEventOccurenceRecord to the RtPlantArea of RtModule via recordEventOccurrence. In step 4328, RtPlantArea tells its RtAreaEventLog to addEvent, RtAreaEventLog sees that at least one workstation client has registered an interest in receiving EventLog records, creates an RtEventLogRecord from the RtEventOccurenceRecord, and queues the RtEventLogRecord, thereby destroying the RtEventOccurenceRecord.

Also referring to FIGURE 43, the object communication diagram is also applicable to disablement of an alarm by causing the ENAB Field of an Alarm Attribute to become FALSE. The alarm fields ofthe Alaπn Attribute are updated to reflect the new Alarm state and an event occuπence record is constructed, and sent to the Module, Plant Area, and workstation applications (Alarm Summary, Event Journal), as needed. Following the disablement of an alarm, the cuπent Alaπn state is "Inactive/ Acknowledged" and the ENAB field is FALSE. The cuπent alaπn information for this alarm has been removed by the Module. A new event occuπence record (alarm DISABLE) has been constructed and is queued for transmission to devices monitoring this Plant Area in this Device.

In step 4310, RtAlarmAttribute receives a writeAttribute, which causes the ENAB Field to become FALSE. In step 4316, RtAlarmAttribute computes a new alarm state, the

"Active/Unacknowledged" state and reads the prototype event descriptor string from RtEventTypeDefinition using AlarmType as an index. In step 4318, RtAlarmAttribute constructs the descriptionString for the RtEventOccurenceRecord, reading cuπent attribute values from the containing RtModule, if necessary. In step 4320, RtAlarmAttribute constructs a new RtEventOccurenceRecord, identifying this event as an alarm disable event. Since the alaπn is disabled when previously active, this event is the clearing of an existing alarm, RtAlarmAttribute tells the RtModule containing RtAlarmAttribute to clearEventOccurrence, identifying RtModule by the handle returned when from clearEventOccurrence. In step 4322, RtModule tells RtActiveAlarmList to clearEventOccurrence, thereby removing the existing entry from the list. In step 4326, RtModule sends the RtEventOccurenceRecord to the RtPlantArea of RtModule via recordEventOccurrence. In step 4328, RtPlantArea tells its RtAreaEventLog to addEvent, RtAreaEventLog sees that at least one workstation client has registered an interest in receiving EventLog records, creates an RtEventLogRecord from the RtEventOccurenceRecord, and queues the RtEventLogRecord, thereby destroying the RtEventOccurenceRecord. Also referring to FIGURE 43, the object communication diagram is also applicable to enablement of an alarm by causing the ENAB Field of an Alaπn Attribute to become TRUE. Prior to enablement of an alarm, the cuπent state ofthe boolean Attribute shows the alarm would be Active if Enabled, AutoAck is False at the Attribute and Module level. The alarm fields ofthe Alarm Attribute are updated to reflect the new Alarm state and an event occurrence record is constructed, and sent to the Module, Plant Area, and workstation applications (Alarm Summary, Event Journal), as needed. Following the disablement ofan alarm, the cuπent Alaπn state is "Active/Unacknowledged" and the ENAB field is TRUE. The current alarm information for this alarm is stored by the Module. A new event occuπence record (alarm Active/Unacknowledged) has been constructed and is queued for transmission to devices monitoring this Plant Area in this Device.

In step 4310, RtAlarmAttribute receives a writeAttribute, which causes the ENAB Field to become TRUE. In step 4312, RtAlarmAttribute gets alarmDisable status from the RtModule containing RtAlarmAttribute so that both Attribute and Module Alarm behavior are ENABLED. In step 4314, RtAlarmAttribute gets alarmAutoack status from the RtModule containing RtAlarmAttribute so that for both Attribute and Module Alarm AUTOACK is DISABLED. In step 4316, RtAlarmAttribute computes a new alarm state, the "Active/Unacknowledged" state and reads the prototype event descriptor string from RtEventTypeDefinition using AlarmType as an index. In step 4318, RtAlarmAttribute constructs the descriptionString for the RtEventOccurenceRecord, reading cuπent attribute values from the containing RtModule, if necessary. In step 4320, RtAlarmAttribute constructs a new RtEventOccurenceRecord. Since the alarm is new, RtAlarmAttribute tells the RtModule containing RtAlarmAttribute to addEventOccurrence, identifying RtModule by the handle returned when from addEventOccurrence. In step 4322, RtModule tells RtActiveAlarmList to addEventOccurrence, thereby adding a new entry to the list. In step 4326, RtModule sends the RtEventOccurenceRecord to the RtPlantArea of RtModule via recordEventOccurrence. In step 4328, RtPlantArea tells its RtAreaEventLog to addEvent, RtAreaEventLog sees that at least one workstation client has registered an interest in receiving EventLog records, creates an RtEventLogRecord from the RtEventOccurenceRecord, and queues the RtEventLogRecord, thereby destroying the RtEventOccurenceRecord.

While the invention has been described with reference to various embodiments, it will be understood that these embodiments are illustrative and that the scope ofthe invention is not limited to them. Many variations, modifications, additions and improvements ofthe embodiments described are possible.

Claims

WE CLAIM:

1. A process conttol system (100) for controlling a plurality of field devices of multiple different field device types including smart-type field devices (132) and non-smart-type field devices (136), the process conttol system comprising: a plurality of distributed conttollers (110) coupled to the field devices; and a software system including a plurality of control modules (440) selectively installable and operative on ones ofthe plurality of distributed conttollers, the software system for communicating with the smart-type and the non-smart-type field devices and for controlling the smart-type and the non-smart-type field devices.

2. A process conttol system according to Claim 1 wherein the software system further includes: a configuration program for configuring the conttol modules and installing the conttol modules on the plurality of distributed conttollers, the distributed controllers retaining the configuration until reconfigured.

3. A process conttol system according to Claim 1 wherein the plurality of conttol modules is configured into a communication services hierarchy including: a remote object commumcations (ROC) level for communicating messages between two conttol modules in a same conttoller and between two control modules in different conttollers, and a low level communications level for interfacing with communications hardware and transmitting messages across the commumcations hardware.

4. A process control system (100) for controlling a plurality of field devices of multiple different field device types including smart-type field devices (132) and non-smart-type field devices (136), the process conttol system comprising: a plurality of distributed conttollers (110) coupled to the field devices; and a plurality of conttol means selectively installable and operative on ones ofthe plurality of distributed conttollers for, in combination, controlling the smart-type and the non-smart- type field devices.

5. A process conttol system (100) comprising: a plurality of field devices of multiple different field device types including smart-type field devices (132) and non-smart-type field devices (136); a plurality of distributed conttollers (110) coupled to the field devices; a workstation (102) coupled to the distributed conttollers; and a plurality of conttol means selectively installable and operative on ones ofthe plurality of distributed conttollers for, in combination, controlling the smart-type and the non-smart- type field devices.

6. A computer program product comprising: a computer usable medium having computable readable code embodied therein including a process conttol software system for controlling a plurality of field devices of multiple different field device types including smart-type field devices (132) and non-smart-type field devices (136), the process conttol system (100) including a plurality of distributed conttollers (110) coupled to the field devices, the executable program code including: a software system including a plurality of control modules (440) selectively installable and operative on ones ofthe plurality of distributed controllers; and a communication and conttol routine for communicating with the smart-type and the non- smart-type field devices and for controlling the smart-type and the non-smart-type field devices.

7. A computer program product according to Claim 6, the executable program code further comprising: a user interface (300) for interfacing with a user; wherein: the smart-type and the non-smart-type field devices operate in compliance with defined bus-based architecture standards and the software system performs smart-type conttol operations and non-smart-type conttol operations transparent to the user over the user interface.

8. A computer program product according to Claim 6 wherein the software system performs smart- type conttol operations using the plurality of conttol modules distributed on the plurality of distributed controllers operating on the smart-type field devices and non-smart-type operations operating on the non- smart-type field devices independently, simultaneously and in parallel.

9. A computer program product according to Claim 6 wherein the software system further includes: a configuration program for configuring the conttol modules and installing the conttol modules on the plurality of distributed conttollers, the distributed controllers retaining the configuration until reconfigured.

10. A computer program product according to Claim 6 wherein the plurality of conttol modules is configured into a communication services hierarchy including: a remote object communications (ROC) level for communicating messages between two conttol modules in a same conttoller and between two control modules in different conttollers, and a low level communications level for interfacing with communications hardware and transmitting messages across the communications hardware. -oo-

11. A process conttol system (100) for controlling a plurality of field devices of multiple different field device types including standard-protocol field devices (6) and non-standard-protocol field devices (12), the process conttol system comprising: a plurality of distributed conttollers (110) coupled to the field devices; and a software system including a plurality of function blocks (522) defined in a standard protocol, the function blocks being selectively installable and operative on ones ofthe plurality of distributed conttollers for selectively controlling a standard-protocol field device and a non- standard-protocol field device.

12. A process control system (100) for controlling a plurality of field devices of multiple different field device types including standard-protocol field devices (6) and non-standard-protocol field devices (12), the process conttol system comprising: a plurality of distributed conttollers (110) coupled to the field devices; and a plurality of conttol means selectively installable and operative on ones ofthe plurality of distributed controllers controlling, in combination, the standard-protocol field devices and the non-standard-protocol field devices.

13. A process conttol system (100) comprising: a plurality of field devices of multiple different field device types including standard-protocol field devices (6) and non-standard-protocol field devices (12); a plurality of distributed conttollers (110) coupled to the field devices; a workstation (102) coupled to the distributed conttollers; and a software system including a plurality of function blocks (522) defined in a standard protocol, the function blocks being selectively installable and operative on ones ofthe plurality of distributed conttollers for selectively controlling a standard-protocol field device and a non- standard-protocol field device.

14. A process control system (100) for controlling a plurality of field devices of multiple different field device types including standard-protocol field devices (6) and non-standard-protocol field devices (12), the process conttol system comprising: a plurality of distributed conttollers (110) coupled to the field devices; and a software system including a plurality of function blocks (522) defined in a standard protocol, the function blocks being selectively definable, creatable, modifiable, and installable as a conttol module that is operative on ones ofthe plurality of distributed controllers for selectively controlling a standard-protocol field device and a non-standard-protocol field device.

15. A process conttol system (100) comprising: a plurality of field devices of multiple different field device types including standard-protocol field devices (6) and non-standard-protocol field devices (12); a plurality of distributed conttollers (110) coupled to the field devices; a workstation (102) coupled to the distributed conttollers; and a software system including a plurality of function blocks (522) defined in a standard protocol, the function blocks being selectively definable, creatable, modifiable, and installable as a conttol module that is operative on ones ofthe plurality of distributed conttollers for selectively controlling a standard-protocol field device and a non-standard-protocol field device.

16. A process control system (100) for controlling a plurality of field devices of multiple different field device types including standard-protocol field devices (6) and non-standard-protocol field devices (12), the process conttol system comprising: a plurality of distributed conttollers (110) coupled to the field devices; and a plurality of control modules (440) selectively definable, creatable, modifiable, and installable and operative on ones of the plurality of distributed conttollers controlling, in combination, the standard-protocol field devices and the non-standard-protocol field devices.

17. A process conttol system according to any of Claims 11, 12, 13, 14, 15 and 16 further comprising: a user interface (300) for interfacing with a user; wherein: the standard-protocol field devices and the non-standard-protocol field devices operate in compliance with the defined Fieldbus architecture standard and the software system performs Standard-protocol conttol operations on standard-protocol field devices and non- standard-protocol field devices transparent to the user over the user interface.

18. A process conttol system according to any of Claims 11, 12, 13, 14, 15 and 16 wherein the software system further includes: a configuration program for configuring the function blocks and installing the function blocks on the plurality of distributed controllers, the distributed conttollers retaining the configuration until reconfigured.

19. A process conttol system according to any of Claims 11, 12, 13, 14, 15 and 16 wherein the plurality of function blocks is configured into a communication services hierarchy including: a remote object communications (ROC) level for communicating messages between two function blocks in a same conttoller and between two function blocks in different conttollers, and a low level communications level for interfacing with communications hardware and transmitting messages across the communications hardware.

20. A computer program product comprising: a computer usable medium having computable readable code embodied therein including a process conttol system (100) for controlling a plurality of field devices of multiple different field device types including standard-protocol field devices (6) and non-standard-protocol field devices (12), the process conttol system including a plurality of distributed conttollers (110) coupled to the field devices, the executable program code comprising: a software system including a plurality of function blocks (522) defined in a standard protocol, the function blocks being selectively installable and operative on ones ofthe plurality of distributed conttollers for selectively controlling a standard-protocol field device and a non- standard-protocol field device.

21. A process conttol system (100) comprising: a field device; a conttoller (110) coupled to the field device; a workstation (102) coupled to the controller, the workstation including a user interface (300); and a software system implementing a conttol sttategy for the process conttol system, the conttol sttategy being selectively defined, created, modified, and apportioned via the user interface into a plurality of conttol sttategy modules, and the plurality of control sttategy modules being selectively distributed among the field device, conttoller and workstation, the control strategy modules operating mutually independently and in parallel.

22. A process conttol system (100) comprising: a field device; a conttol means coupled to the field device for controlling the field device; an interface means coupled to the conttol means for interfacing the conttol process system to a user; and a conttol sttategy means for defining, creating, modifying, and implementing a process conttol sttategy under direction of the user, the user selectively apportioning the conttol sttategy means into a plurality of conttol sttategy modules, and the user selectively distributing the conttol sttategy modules among the field device, conttol means and interface means, the conttol sttategy modules operating mutually independently and in parallel.

23. A process conttol system according to either Claim 21 or Claim 22, wherein: the software system further includes a user interface for interfacing the process conttol system to a user; and the conttol sttategy is selectively defined, created, modified, and apportioned, and the plurality of conttol sttategy modules selectively distributed by the user.

24. A process control system according to either Claim 21 or Claim 22, wherein: the field device includes a conttol element; and the software system includes a conttol sttategy module that is distributed to the field device conttol element.

25. A process control system according to either Claim 21 or Claim 22 wherein: the field device is a Fieldbus standard device including a conttol element; and a conttol sttategy module is distributed to the conttol element and operates selectively as a Fieldbus standard function block or a custom, user-defined conttol module.

26. A process control system according to either Claim 21 or Claim 22 wherein the software system further includes: a configuration program for defining, creating and configuring the conttol sttategy modules and installing the control sttategy modules among the field device, controller and workstation, the distributed conttollers retaining the configuration until reconfigured.

27. A process conttol system according to either Claim 21 or Claim 22, wherein: the conttol strategy modules are selectively defined, modified, and created by a user creating custom control sttategy modules; and the control sttategy modules are selectively distributed by transferring a selected conttol strategy module to a selected one ofthe field device, controller and workstation.

28. A process control system according to either Claim 21 or Claim 22 wherein the plurality of conttol sttategy modules are configured into a communication services hierarchy including: a remote object communications (ROC) level for communicating messages between two control sttategy modules in a same controller and between two conttol sttategy modules in different conttollers, and a low level communications level for interfacing with communications hardware and transmitting messages across the communications hardware.

29. A method of operating a process conttol system (100) including a distributed conttoller (110) and a distributed field device comprising the steps of: executing process conttol operations; executing an editor program during execution ofthe process conttol system operations; using the editor program, defining a conttol sttategy including the steps of : building a plurality of function blocks (522) and conttol modules (440); and downloading user-specified function blocks and conttol modules selectively among the distributed conttoller and the distributed field device; executing the function blocks and conttol modules distributed to the conttoller and distributed to the field device mutually independently and in parallel.

30. A computer program product for use in a process conttol system (100) including a field device, a controller (110) coupled to the field device, and a workstation (102) coupled to the conttoller, the computer program product comprising: a computer usable medium having computable readable code embodied therein including a software system implementing a conttol sttategy for the process control system, the conttol sttategy being selectively definable, creatable, modifiable, and apportionable into a plurality of control sttategy modules, and the plurality of conttol sttategy modules being selectively distributable among the field device, conttoller and workstation, the control sttategy modules operating mutually independently and in parallel.

31. A process conttol system (100) comprising: a field device including a source of diagnostic information; a conttoller (110) coupled to the field device; a workstation (102) coupled to the controller and including a user interface (300); and a software system implementing a diagnostic monitoring and display program for the process conttol system, the diagnostic monitoring and display program including: a plurality of diagnostic modules selectively defined and created via the user interface for access using the diagnostic monitoring and display program, the plurality of diagnostic modules upon creation being selectively distributed among the field device, the conttoller and the workstation, the diagnostic modules operating mutually independently and in parallel accessing the source of diagnostic information; and a display routine for accessing diagnostic information from the plurality of diagnostic modules and displaying the diagnostic information accessed from the plurality of diagnostic modules uniformly for all diagnostic modules in the process conttol system so that the diagnostic information relating to a process that operates both in the conttoller and in the field device is displayed in the same manner regardless of the source of the diagnostic information.

32. A process conttol system (100) comprising: a field device mcluding a source of diagnostic information; a conttoller (110) coupled to the field device; a workstation (102) coupled to the conttoller and including a user interface (300); and a software system implementing a diagnostic monitoring and display program for the process conttol system, the diagnostic monitoring and display program including: a plurality of conttol modules (440) for selectively implementing a process conttol strategy, a plurality of diagnostic modules selectively defined and created via the user interface for access using the diagnostic monitoring and display program, the plurality of diagnostic modules upon creation being selectively distributed among the field device, the conttoller and the workstation, the diagnostic modules operating mutually independently and in parallel accessing the source of diagnostic information; and a display routine for accessing diagnostic information from the plurality of diagnostic modules and a conttol scheme from the plurality of control modules and for respectively displaying the diagnostic information accessed from the plurality of diagnostic modules and the conttol sttategy accessed from the plurality of conttol modules so that the diagnostic information and the conttol information are accessed in the same manner.

33. A process conttol system (100) comprising: a plurality of field devices, a field device ofthe plurality of field devices including a source of diagnostic information; a plurality of conttollers (110), a conttoller ofthe plurality of conttollers being coupled to a field device of the plurality of field devices; a workstation (102) coupled to the conttoller and including a user interface (300); and a software system implementing a diagnostic monitoring and display program for the process conttol system, the diagnostic monitoring and display program including: a plurality of diagnostic modules selectively defined and created via the user interface for access using the diagnostic monitoring and display program, the plurality of diagnostic modules upon creation being selectively distributed among the field devices, the conttollers and workstation, the diagnostic modules operating mutually independently and in parallel; and a display routine for accessing diagnostic information from the plurality of diagnostic modules operating mutually independently on the field devices, the conttollers and the workstation and displaying the diagnostic information accessed from the plurality of diagnostic modules uniformly so that the diagnostic information relating to a process that operates more than one ofthe field devices, the conttollers and the workstation is displayed as being generated at a single location.

34. A process conttol system (100) comprising: a plurality of field devices, a field device ofthe plurality of field devices including a source of diagnostic information; a plurality of conttol means for controlling a field device, a conttol means of the plurality of conttol means being coupled to a field device of the plurality of field devices; an interface means coupled to the plurality of conttol means for interfacing the conttol process system to a user; a diagnostic means for implementing a process conttol sttategy, the diagnostic means being selectively defined and created as a plurality of diagnostic modules, the plurality of diagnostic modules upon creation being selectively distributed among the field device, conttol means and interface means, the diagnostic modules operating mutually independently and in parallel; and a display means for accessing diagnostic information from the plurality of diagnostic means operating mutually independently on the field devices, the conttol means and the interface means and displaying the diagnostic information accessed from the plurality of diagnostic modules uniformly so that the diagnostic information relating to a process that operates more than one ofthe field devices, the conttol means and the interface means is displayed as being generated at a single location.

35. A process conttol system (100) comprising: a field device including a source of diagnostic information; a controller (110) coupled to the field device; a workstation (102) coupled to the conttoller and including a user interface (300); and a software system implementing a diagnostic monitoring and display program for the process conttol system, the diagnostic monitoring and display program including: a control sttategy for the process conttol system, the conttol sttategy being selectively apportioned into a plurality of conttol sttategy modules and selectively distributed among the field device, conttoller and workstation, the conttol sttategy modules operating mutually independently and in parallel; a plurality of diagnostic modules selectively defined and created via the user interface for access using the diagnostic monitoring and display program, the plurality of diagnostic modules upon creation being selectively distributed among the field device, the conttoller and the workstation, the diagnostic modules operating mutually independently and in parallel accessing the source of diagnostic information; and a display routine for accessing diagnostic information from the plurality of diagnostic modules and displaying the conttol sttategy and the diagnostic information accessed from the plurality of diagnostic modules uniformly so that the diagnostic information relating to a process that operates both in the controller and in the field device is displayed as being generated at a single location.

36. A process conttol system according to any of Claims 31, 32, 33, 34, and 35 wherein: the plurality of diagnostic modules are selectively defined and created, and selectively distributed by a user.

37. A process conttol system according to any of Claims 31, 32, 33, 34, and 35, wherein: the field device includes a conttol element; and a diagnostic module ofthe plurality of diagnostic modules is distributed to the field device and monitors a condition or status ofthe conttol element.

38. A process conttol system according to any of Claims 31, 32, 33, 34, and 35, further comprising: a network coupled to the conttoller; and an external node coupled to the conttoller through the network so that device information including real-time data, history information, event statistics, configuration data and diagnostic information are accessed using network standard communications.

39. A computer program product comprising: a computer usable medium having computable readable code embodied therein for controlling a process control system (100) including a source of diagnostic information, a conttoller coupled to the field device, and a workstation (102) coupled to the conttoller and including a user interface (300), the executing program code implementing a diagnostic monitoring and display program for the process conttol system, the diagnostic monitoring and display program including: a plurality of diagnostic modules selectively defined and created via the user interface for access using the diagnostic monitoring and display program, the plurality of diagnostic modules upon creation being selectively distributed among the field device, the conttoller and the workstation, the diagnostic modules operating mutually independently and in parallel accessing the source of diagnostic information; and a display routine for accessing diagnostic information from the plurality of diagnostic modules and displaying the diagnostic information accessed from the plurality of diagnostic modules uniformly for all diagnostic modules in the process conttol system so that the diagnostic information relating to a process that operates both in the conttoller and in the field device is displayed in the same manner regardless of the source ofthe diagnostic information.

40. A computer program product comprising: a computer usable medium having computable readable code embodied therein for controlling a process conttol system (100) including a field device having a source of diagnostic information, a controller coupled to the field device, a workstation (102) coupled to the conttoller, and a user interface (300), the computable readable code implementing a diagnostic monitoring and display program for the process conttol system, the diagnostic monitoring and display program including: a plurality of conttol modules (440) for selectively implementing a process conttol sttategy; a plurality of diagnostic modules selectively defined and created via the user interface for access using the diagnostic monitoring and display program, the plurality of diagnostic modules upon creation being selectively distributed among the field device, the conttoller and the workstation, the diagnostic modules operating mutually independently and in parallel accessing the source of diagnostic information; and a display routine for accessing diagnostic information from the plurality of diagnostic modules and a conttol scheme from the plurality of conttol modules and for respectively displaying the diagnostic information accessed from the plurality of diagnostic modules and the control sttategy accessed from the plurality of conttol modules so that the diagnostic information and the conttol information are accessed in the same manner.

41. A conttol system for controlling a process comprising: a conttoller coupled to the process; and a software system executing on the conttoller and implementing a conttol sttategy for controlling the process, the conttol sttategy being defined by a layered hierarchy of modules including elemental modules containing exclusively one or more primitives and composite modules.

42. A process conttol system (100) for controlling a plurality of field devices, the process conttol system comprising: a plurality of distributed conttollers (110) coupled to the field devices for controlling a process; and a distributed software system executing on the plurality of distributed conttollers and implementing a conttol sttategy for controlling the process, the control sttategy being defined by a layered hierarchy of modules distributed for execution among the plurality of distributed conttollers, the hierarchy of modules including elemental modules containing exclusively one or more primitives and composite modules.

43. A process control system (100) comprising: a plurality of field devices; a plurality of distributed conttollers (110) coupled to the field devices for controlling a process; and a distributed software system executing on the plurality of distributed conttollers and implementing a conttol sttategy for conttolling the process, the conttol sttategy being defined by a layered hierarchy of modules distributed for execution among the plurality of distributed conttollers and the plurality of field devices, the hierarchy of modules including elemental modules containing exclusively one or more primitives and composite modules.

44. A conttol system for conttolling a process under direction of a user, the conttol system comprising: a controller (110) coupled to the process; and a software system executing on the conttoller and implementing a conttol sttategy for controlling the process, the conttol sttategy being defined by a plurality of conttol modules (440) which are objects of a container class, a conttol module of the plurality of conttol modules having a specified task and a predefined external interface, the conttol module being encapsulated in the software system and accessed through the predefined external interfaces so that the conttol module is user-modifiable.

45. A conttol system according to any of Claims 41, 42, 43, and 44 wherein: the process includes a field device; and an elemental module is an elemental function block defined in accordance with a Fieldbus standard protocol.

46. A conttol system according to any of Claims 41, 42, 43, and 44 further comprising: a user interface coupled to the conttoller for specifying the control strategy, the control sttategy being user-specified by a module type of constituent elemental modules and composite modules, by interconnections between the constituent modules and by input/ output connections ofthe constituent modules.

47. A conttol system according to Claim 46 wherein: the user interface for modifying the control sttategy is implemented in a plurality of process conttol programming languages.

48. A control system according to any of Claims 41, 42, 43, and 44 wherein the software system further includes: a configuration program for defining the conttol sttategy and installing the conttol strategy on the conttoller, the controller retaining the configuration until reconfigured.

49. A computer program product comprising: a computer usable medium having computable readable code embodied therein for controlling a process conttol system (100) for conttolling a plurality of field devices, he process control system including a plurality of distributed conttollers (110) coupled to the field devices for controlling a process, the computable readable code including: a distributed software system executing on the plurality of distributed conttollers and implementing a conttol sttategy for conttolling the process, the conttol sttategy being defined by a layered hierarchy of modules distributed for execution among the plurality of distributed conttollers, the hierarchy of modules including elemental modules containing exclusively one or more primitives and composite modules.

50. A computer program product comprising: a computer usable medium having computable readable code embodied therein for conttolling a process control system (100) including a plurality of field devices and a plurality of distributed conttollers (110) coupled to the field devices for conttolling a process, the computable readable code including: a distributed software system executing on the plurality of distributed conttollers and implementing a control sttategy for conttolling the process, the conttol strategy being defined by a layered hierarchy of modules distributed for execution among the plurality of distributed conttollers and the plurality of field devices, the hierarchy of modules including elemental modules containing exclusively one or more primitives and composite modules.

51. A process conttol system (100) comprising: a process; a plurality of conttollers (110) coupled to the process; a workstation (102) coupled to the plurality of controllers and including a user interface (300); and a software system including a network operating system and implementing a routine for automatically sensing a connection of a conttoller to a network and inco╧åorating the conttoller into the network operating system.

52. A process control system according to Claim 51 wherein the software system further comprises: a software routine responsive to automatic sensing of a connection of a controller to the network for automatically configuring an input/output (I/O) subsystem in a conttol system.

53. A process control system according to Claim 51, wherein the routine for automatically sensing a connection of a conttoller to a network and inco╧åorating the conttoller into a network operating system comprises: means for connecting a conttoller to the network; means operative in the connected conttoller for sending a request to confirm a network address assignment, the request being accompanied by the conttoller media access conttol (MAC) address; a network configuration service including: means for receiving the request to confirm; means for searching a table of configured devices for a matching MAC address; means operative when the MAC address matches for generating device and network information including a network address from a device table; means operative when the MAC address does not match for generating device and network information including a network address from MAC address-based default information and adding the default information to the device table; and means operative when the MAC address does not match for assigning the connected conttoller under user conttol either as a new device added to the device table or as a device configuration previously existing in the device table.

54. A method of automatically sensing a connection of a controller to a network and inco╧åorating the controller into a network operating system including the steps of: connecting a conttoller to the network; sending, by the connected conttoller, a request to confirm a network address assignment, the request being accompanied by the conttoller media access control (MAC) address; receiving, by a network configuration service, the request to confirm and responding by performing the steps of: searching a table of configured devices for a matching MAC address; when the MAC address matches, generating device and network information including a network address from a device table; when the MAC address does not match, generating device and network information including a network address from MAC address-based default information and adding the default information to the device table; and when the MAC address does not match, assigning the connected conttoller under user conttol either as a new device added to the device table or as a device configuration previously existing in the device table.

55. A method of automatically configuring an input/output (I/O) subsystem in a control system comprising the steps of: inte╧Çogating an I/O Card at a user-specified card position to determine a Card Type and a number of I/O Ports in the I/O Card; determining whether the inte╧Çogated I/O Card is previously defined in an engineering database; if the I/O Card is not previously defined in the engineering database, defining an I/O Card of a suitable type and I/O Ports of a suitable number, the suitable type and number being predetermined for the card position; inte╧Çogating the I/O Ports of an I/O Card in accordance with the Card Type to determine a Port Type and a number of I/O Devices on the I/O Port; if the I/O Port is not previously defined in the engineering database for the port address, defining an I/O Port of a suitable type and I/O Devices of a suitable number, the suitable type and number being predefined; inte╧Çogating the I/O Devices in accordance with the Port Type to determine a Device Type; if the I/O Device is not previously defined in the engineering database for the device address, defining an I/O Device of a suitable type, the suitable type being predefined; and creating instrument signal tags (ISTs) for primary signal sources on the I/O Ports and the I/O Devices.

56. A method according to Claim 55, further comprising the steps of: determining whether an I/O Card exists in the engineering database for the card position; if the I/O Card exists in the engineering database, determining whether the Card Type in the engineering database matches the Card Type sensed at the card position, if the Card Type in the engineering database does not match the Card Type sensed at the card position executing the steps of: generating a graphic notification ofthe mismatch; inte╧Çogating a user to determine whether the engineering database is to be changed to include the sensed Card Type; and changing the Card Type in the engineering database to the sensed Card Type if requested by the user.

57. A method according to Claim 55, further comprising the steps of: determining whether an I/O Port exists in the engineering database for the port address; if the I/O Port exists in the engineering database, determining whether the Port Type in the engineering database matches the type ofthe sensed I/O Port sensed at the port address; if the Port Type in the engineering database does not match the type ofthe sensed I/O Port executing the steps of: requesting advisement of the user to determine whether the engineering database is to be updated to match the sensed I/O Port; and changing the Port Type in the engineering database to the sensed Port Type if requested by the user.

58. A method according to Claim 55, further comprising the steps of: determining whether an I/O Device exists in the engineering database for the device address; if the I/O Device exists in the engineering database, determining whether the Device Type in the engineering database matches the type ofthe sensed I/O Device sensed at the device address; if the Device Type in the engineering database does not match the type ofthe sensed I/O Device executing the steps of: requesting advisement ofthe user to determine whether the engineering database is to be updated to match the sensed I/O Device; and changing the Device Type in the engineering database to the sensed Device Type if requested by the user.

59. A computer program product comprising: a computer usable medium having computable readable code embodied therein for automatically sensing a connection of a conttoller to a network and inco╧åorating the conttoller into a network operating system including: a routine for connecting a conttoller to the network; a routine for sending, by the connected conttoller, a request to confirm a network address assignment, the request being accompanied by the conttoller media access conttol (MAC) address; a routine for receiving, by a network configuration service, the request to confirm and responding by executing routines including: a routine for searching a table of configured devices for a matching MAC address; a routine for determining when the MAC address matches, and for a matching address generating device and network information including a network address from a device table; a routine for determining when the MAC address does not match, and for a nonmatching address generating device and network information including a network address from MAC address-based default information and adding the default information to the device table; and a routine for determimng when the MAC address does not match, and for a nonmatching address assigning the connected conttoller under user conttol either as a new device added to the device table or as a device configuration previously existing in the device table.

60. A computer program product comprising: a computer usable medium having computable readable code embodied therein for automatically configuring an input output (I/O) subsystem in a conttol system comprising: a routine for inte╧Çogati g an I/O Card at a user-specified card position to determine a Card Type and a number of I/O Ports in the I/O Card; a routine for determining whether the inte╧Çogated I/O Card is previously defined in an engineering database; a routine operative when the I/O Card is not previously defined in the engineering database and defining an I/O Card of a suitable type and I/O Ports of a suitable number, the suitable type and number being predetermined for the card position; a routine for inte╧Çogating the I/O Ports of an I/O Card in accordance with the Card Type to determine a Port Type and a number of I/O Devices on the I/O Port; a routine operative when the I/O Port is not previously defined in the engineering database for the port address, the routine defining an I/O Port of a suitable type and I/O Devices of a suitable number, the suitable type and number being predefined; a routine for inte╧Çogating the I/O Devices in accordance with the Port Type to determine a Device Type; a routine operative when the I/O Device is not previously defined in the engineering database for the device address, the routine defining an I/O Device of a suitable type, the suitable type being predefined; and a routine for creating instrument signal tags (ISTs) for primary signal sources on the I/O Ports and the I/O Devices.

61. A process control system (100) comprising: a process; a plurality of devices coupled to the process; a communication network coupled to the devices; a workstation (102) coupled to the plurality of devices via the network and including a user interface (300); and a software system executable on the network and implementing a routine for automatically sensing a connection of a device to a network and placing the connected device in an accessible state for communicating with a user via the user interface.

62. A conttol system comprising: a network; a plurality of devices coupled to the network; a distributed conttoller coupled to the plurality of devices and conttolling the plurality of devices according to a defined conttol configuration, the distributed conttoller including: a conttol logic for sensing a device that is connected to the network but not included in the defined conttol configuration; a conttol logic for supplying initial interconnect information to the connected device; and a conttol logic for uploading configuration parameters from the connected device to the distributed conttoller.

63. A process conttol system according to either Claim 61 or Claim 62 wherein the software system further comprises: a routine for configuring the connected device in a network conttol configuration ofthe plurality of devices.

64. A process conttol system according to Claim 63 wherein the routine for configuring the connected device further comprises: a user-interactive routine for determining a device type ofthe connected device; a user-interactive routine for determining a role ofthe connected device with respect to the process conttol system; a user-interactive routine for assigning a physical device tag the determined role; and a user-interactive routine for verifying connection of the device to the network.

65. A process control system according to Claim 63 wherein the routine for configuring the connected device further comprises: a user-interactive routine for initiating calibrating the connected device; and a user-interactive routine for configuring the device within an overall conttol scheme of the process control system.

66. A process conttol system according to either Claim 61 or Claim 62 wherein the software system further comprises: a routine for commissioning the connected device including: a user-interactive routine for assigning a physical device tag, a device address, and a device identification to the connected device; and a user-interactive routine for installing a conttol sttategy to the digital device.

67. A method of configuring a conttol system comprising: predetermining a configuration of devices coupled to a network; sensing a connection to the network of a device that is not included in the predetermined configuration; assigning the connected device a standby address which allows access to device information and configuration parameters of the connected device; commissioning the connected device into an operational state in communication with the conttol system; and configuring the connected device in combination with the predetermined configuration of devices.

68. A method according to Claim 67 wherein commissioning the connected device further comprises: assigning to the connected device a physical device tag, a device address, and a device identification; installing a control sttategy to the connected device; and placing the connected device in an operational state in communication with the network.

69. A method according to Claim 67 wherein configuring the connected device further comprises: inte╧Çogating the connected device to determine a device type; determining a role ofthe connected device in the context ofthe predetermined configuration; and assigning a physical device tag so that the determined role is set.

70. A computer program product comprising: a computer usable medium having computable readable code embodied therein for configuring a conttol system including: a routine for predetermining a configuration of devices coupled to a network; a routine for sensing a connection to the network of a device that is not included in the predetermined configuration; a routine for assigning the connected device a standby address which allows access to device information and configuration parameters of the connected device; a routine for commissioning the connected device into an operational state in communication with the conttol system; and a routine for configuring the connected device in combination with the predetermined configuration of devices.

71. A process conttol system (100) for conttolling a process according to a conttol sttategy, the process conttol system comprising: a computer system including a processor, an input interface and a display coupled to the process; a field device coupled to the process; a conttoller coupled to the field device and communicatively coupled to the computer system; and a software system including: an interactive, user-directed process configuration program including a plurality of conttol language editors for selecting the control strategy using a conttol language selected from a plurality of control languages, the process configuration program creating an executable conttol module and downloading the executable conttol module selectively among the computer system, the field device, and the controller; and an executable conttol module selectively created, downloaded and executed, the control module being configurable by the process configuration program to configure a control language execution engine.

72. A process control system (100) comprising: a field device; a conttoller (110) coupled to the field device; a workstation (102) coupled to the conttoller and having an interactive input interface and a display; and a software system including: a user interface (300) responsive to the interactive input interface for interfacing the process conttol system to a user; a routine for implementing a control strategy for the process conttol system, the control sttategy being selectively apportioned into a plurality of conttol modules (440) and selectively distributed among the field device, the conttoller, and the workstation; and an interactive, user-directed process configuration program including a plmality of conttol language editors for selecting the conttol sttategy using a control language selected from a plurality of conttol languages, the process configuration program selectively creating the conttol modules implementing the conttol strategy, selectively apportioning the control modules, and selectively distributing the conttol modules among the field device, the conttoller, and the workstation for executing the conttol sttategy.

73. A process conttol system (100) for conttolling a plurality of field devices of multiple different field device types, the process conttol system comprising: a plurality of conttollers (110) coupled to the field devices; and a software system including: a user interface (300) for interfacing the process conttol system to a user; a plurality of control modules (440) selectively created, downloaded, and executed on ones ofthe plurality of conttollers, the software system for communicating with the multiple different field device types and for controlling the multiple different field devices independently of conttol of control modules in other field devices; and an interactive, user-directed process configuration program including a plurality of conttol language editors for selectively installing and configuring the conttol modules using a conttol language selected from a plurality of conttol languages.

74. A process control system according to Claim 71, Claim 72 or Claim 73, wherein: the software system is distributed among the processor and the conttoller including: an interactive input and display routine executable on the processor, and a plurality of conttol language execution engines executable on the conttoller for implementing respective languages ofthe plurality of conttol languages.

75. A process conttol system according to Claim 71, Claim 72, or Claim 73 further comprising: a plurality of field devices; a plurality of controllers coupled to the field devices, wherein: the software system is distributed among the workstation and the plurality of conttollers and includes: an interactive input and display routine executable on the workstation, and a plurality of conttol language execution engines selectively created, apportioned, distributed, and executable on the plurality of conttollers for implementing the plurality of conttol languages.

76. A method for configuring a process conttol environment, the process conttol environment including a computer system having a processor coupled to a display device, the method comprising: providing a plurality of instructional sections, an instructional section setting forth information relating to configuring the process conttol environment; selecting a conttol language editor for defining a process control environment configuration; activating the selected conttol language editor; displaying, on the display device, a sequence of configuration screen presentations relating to the instruction sections as directed in terms ofthe selected conttol language editor; and guiding a user through the configuration of the process conttol environment via the sequence of configuration screen presentations; interactively creating a plurality of independent conttol modules (440); configuring the plurality of conttol modules to create a conttol sttategy; transferring the conttol sttategy to a selected conttoller executing a conttol language execution engine corresponding to the selected conttol language editor, the selected conttoller executing the conttol sttategy independently of execution of other control strategies.

77. A computer program product comprising: a computer usable medium having computable readable code embodied therein for conttolling a process conttol system (100) according to a conttol sttategy, the process conttol system including a computer system with a processor, an input interface and a display coupled to the process; a field device coupled to the process; a controller coupled to the field device and communicatively coupled to the computer system; and a software system further including: an interactive, user-directed process configuration program including a plurality of conttol language editors for selecting the conttol sttategy using a conttol language selected from a plurality of conttol languages, the process configuration program creating an executable conttol module and downloading the executable conttol module selectively among the computer system, the field device, and the conttoller; and an executable conttol module selectively created, downloaded and executed, the control module being configurable by the process configuration program to configure a control language execution engine.

78. A computer program product comprising: a computer usable medium having computable readable code embodied therein for managing a process conttol system (100) including a field device, a conttoller coupled to the field device, a workstation (102) coupled to the conttoller and having an interactive input interface and a display; and a software system including: a user interface (300) responsive to the interactive input interface for interfacing the process control system to a user; a routine for implementing a control sttategy for the process control system, the control sttategy being selectively apportioned into a plurality of conttol modules (440) and selectively distributed among the field device, the controller, and the workstation; and an interactive, user-directed process configuration program including a plurality of conttol language editors for selecting the conttol sttategy using a conttol language selected from a plurality of conttol languages, the process configuration program selectively creating the conttol modules implementing the conttol sttategy, selectively apportioning the conttol modules, and selectively distributing the control modules among the field device, the conttoller, and the workstation for executing the conttol sttategy.

79. A computer program product comprising: a computer usable medium having computable readable code embodied therein for conttolling a plurality of field devices of multiple different field device types, the process control system -lUo-

(100) including a plurality of conttollers (110) coupled to the field devices and a software system including: a user interface (300) for interfacing the process conttol system to a user; a plurality of conttol modules (440) selectively created, downloaded, and executed on ones of the plurality of conttollers, the software system for communicating with the multiple different field device types and for controlling the multiple different field devices independently of conttol of conttol modules in other field devices; and an interactive, user-directed process configuration program including a plurality of conttol language editors for selectively installing and configuring the conttol modules using a conttol language selected from a plurality of conttol languages.

80. A computer program product comprising: a computer usable medium having computable readable code embodied therein for configuring a process control environment, the process conttol environment including a computer system having a processor coupled to a display device and a software system including: a routine for providing a plurality of instructional sections, an instructional section setting forth information relating to configuring the process control environment; a routine for selecting a conttol language editor for defining a process conttol environment configuration; a routine for activating the selected conttol language editor; a routine for displaying, on the display device, a sequence of configuration screen presentations relating to the instruction sections as directed in terms ofthe selected conttol language editor; and a routine for guiding a user through the configuration ofthe process conttol environment via the sequence of configuration screen presentations; a routine for interactively creating a plurality of independent conttol modules (440); a routine for configuring the plurality of control modules to create a conttol sttategy; a routine for transferring the conttol sttategy to a selected conttoller executing a control language execution engine co╧Çesponding to the selected conttol language editor, the selected conttoller executing the conttol strategy independently of execution of other conttol strategies.

81. A process control system (100) comprising: a field device including a source of event condition information; a conttoller (110) coupled to the field device; a workstation (102) coupled to the conttoller and including a user interface (300); and a software system implementing an event condition monitoring and display program for the process conttol system, the event condition monitoring and display program including: a plurality of conttol modules (440) including event attributes, the conttol modules being selectively controlled and selectively distributed among the field device, the conttoller and the workstation, the conttol modules operating mutually independently and in parallel accumulating event condition information; a display routine for accessing the event condition information from the plurality of conttol modules and displaying the event condition information accessed from the plurality of conttol modules in an order of priority selected by a user; and a configuration routine for user-selectively defining and creating the control modules and the event attributes ofthe control modules, and for user selectively distributing the control modules among the field device, the conttoller, and the workstation.

82. A process conttol system according to claim 81, wherein the software system further comprises: a routine for priming the event attributes with a cu╧Çent alarm set subject to a current user responsibility scope to begin accumulating an event count when a new user logs-on.

83. A method for operating a process conttol system (100) comprising the steps of: defining a plurality of conditions as events, the events being associated with a plant area; activating an event journal for logging event conditions; configuring an alarm behavior including the steps of: creating an alarm attribute, the alarm attribute being selectively created in a conttol module or in an equipment module; selectively disabling or enabling the created alarm attribute; selectively placing an enabled alarm attribute in an acknowledged state or an unacknowledged state; and selectively placing the alarm attribute in an active state or an inactive state; selecting a priority for the alarm attribute; and consolidating a plurality of active alarm conditions into a subset of highest priority alarms.

84. A computer program product comprising: a computer usable medium having computable readable code embodied therein including a process conttol system (100) including a field device including a source of event condition information, a controller coupled to the field device, and computer coupled to the conttoller and including a user interface (300), the computer program product including an event condition monitoring and display program for the process conttol system, the event condition monitoring and display program including: a plmality of conttol modules (440) including event attributes, the plurality of control modules being selectively controlled and selectively distributed among the field device, the conttoller and the workstation, the conttol modules operating mutually independently and in parallel accumulating event condition information; a display routine for accessing the event condition information from the plurality of conttol modules and displaying the event condition information accessed from the plurality of conttol modules in an order of priority selected by the user; and a configuration routine for user-selectively defining and creating the conttol modules and the event attributes ofthe conttol modules, and for user selectively distributing the control modules among the field device, the conttoller, and the workstation.

85. A computer program product comprising: a computer usable medium having computable readable code embodied therein including a process conttol system (100) further including: a routine for defining a plurality of conditions as events, the events being associated with a plant area; a routine for activating an event journal for logging event conditions; a routine for configuring an alarm behavior including: a routine for creating an alarm attribute, the alarm attribute being selectively created in a conttol module or in an equipment module; a routine for selectively disabling or enabling the created alarm attribute; a routine for selectively placing an enabled alarm attribute in an acknowledged state or an unacknowledged state; and a routine for selectively placing the alarm attribute in an active state or an inactive state; a routine for selecting a priority for the alarm attribute; and a routine for consolidating a plurality of active alarm conditions into a subset of highest priority alarms.

86. A computer program product according to either Claim 84 or Claim 85 further comprising: a routine for priming the event attributes with a cu╧Çent alarm set subject to a current user responsibility scope to begin accumulating an event count when a new user logs-on.

87. A computer program product according to either Claim 84 or Claim 85, further comprising: a routine for transitioning between a plurality of alarm attribute states, including: a routine for selectively disabling or enabling an alarm attribute, the alarm attribute being in an inactive and acknowledged condition when the alarm attribute is disabled; a routine for configuring the alarm attribute with a boolean attribute so that an alarm is active when the boolean attribute is true and the alarm is inactive when the boolean attribute is true:

. ..

-1 9-

a routine for optionally inverting the sense ofthe boolean attribute with an invert attribute; and a routine for when the alarm attribute is enabled, selectively acknowledging the alarm attribute or unacknowledging the alarm attribute.

88. A computer program product according to either Claim 84 or Claim 85, wherein the routine for consolidating a plurality of active alarm conditions includes: a routine for ranking an alarm condition in an order of decreasing order of precedence based on an ordered priority including: a routine for first ranking an unacknowledged condition with precedence over an acknowledged condition; a routine for second ranking a condition in order of High selected priority, Medium selected priority, then Low selected priority; and a routine for third ranking a condition in order of time of detection with a newest timestamp condition having a precedence over an older timestamp condition.

89. A computer program product according to either Claim 84 or Claim 85, wherein the routine for consolidating a plurality of active alarm conditions includes: a routine for user-level consolidation including: a routine for displaying an alarm banner in a graphical user interface (300); a routine for granting alarm privilege over a one or more plant areas to a user; a routine for predefining an attribute container supporting an alarms attribute; a routine for constructing a display referencing the attribute container; and a routine for allowing access to highest priority alarms based on the display referencing the attribute container.

90. A computer program product according to either Claim 84 or Claim 85, wherein: the conditions defined as events are conditions selected from among the conditions of: alarms; alarm acknowledgments; user changes including attributes written by the user, methods invoked by the user, and log- in and log-out operations by the user; configuration changes to a run time system including system installation and de-installation operations; Sequential Function Chart (SFC) state changes; Operator Attention Requests (OARs); and miscellaneous events including non-alarm state ttansitions and equipment state changes.