WO2016102194A1

WO2016102194A1 - Arrangement and method for operating a field device with a web server

Info

Publication number: WO2016102194A1
Application number: PCT/EP2015/079289
Authority: WO
Inventors: Holger Seguin; Florian Schorradt
Original assignee: Endress+Hauser Wetzer Gmbh+Co. Kg
Priority date: 2014-12-23
Filing date: 2015-12-10
Publication date: 2016-06-30
Also published as: DE102014119515A1

Abstract

A method for operating a field device (F) that comprises a first web server (C1) and an internal memory unit (S1). To request data from the field device (F), a client (CL) in an operator unit (BG) sends an enquiry to the first web server (C1) via the first communication link (VI). The first web server (C1) transmits the data to the client (CL) if the data are present in the internal memory unit (S1). Otherwise, the first web server (C1) directs the enquiry to the second web server (C2) via the second communication link (V2), which reads the data from an external memory unit (S2) and sends them to the first web server (C1), with the first web server (C1) subsequently sending the data to the client (CL). It is therefore possible for data and functions of the field device (F) to be relocated to a second server (C2) having an external memory unit (S2) or database. The data may be e.g. parameter labels, error texts, help texts and menu labels in different languages. The values of the parameters that influence the measurement response (inputs) and the yield (outputs) must be stored in the memory unit (S1) that is internal in the field device (F).

Description

ARRANGEMENT AND METHOD FOR OPERATING A FIELD DEVICE WITH

A WEBSERVER

The invention relates to a method for operating a field device and an arrangement comprising a field device.

A variety of field devices, which find use in industrial plants, are already known from the prior art and are used inter alia by the

Applicant manufactured and sold.

Such field devices can serve, for example, for controlling, monitoring and displaying a process variable. In particular, a multi-channel process data acquisition device has become known, to which one or more sensors can be connected and which serves for storing and / or processing one or more measurement signals, which measurement signal or which measurement signals are transmitted from one or more of the sensors to the process data acquisition device. Such a thing

Messdatenerfassungsgerät is known, for example, from the patent EP 1390697 B1 and is by the applicant under the name ECOGRAPH or

MEMOGRAPH distributed.

The settings of these field devices are sometimes very extensive. Furthermore, it is not only the number of settings on the basis of which such a field device requires sufficient space but also associated additional information such as a description in the form of auxiliary instructions, operating instructions, etc. These documents may even be available in different languages to an operation independently country borders and / or linguistic regions.

However, this conflicts with notoriously scarce resources in the field of industrial equipment, such as memory and computing power. This is partly due to the fact that such field devices are often only supplied via a so-called two-wire line with a current between 4 to 20 mA.

In addition, field devices have become known which can be operated via a web browser. Such a possibility is described, for example, in the patent application US 2008/0082637 A1. There, an automation device is configured by means of an operating tool, which operating tool is connected via the Internet with a web server in a gateway. Based on this, the object of the invention is to specify a resource-saving option for retrieving data, in particular field-device-related data, from a field device. This object is achieved by a method for operating a field device and an arrangement comprising a field device.

With regard to the method, the object is achieved by a method for operating a field device, in particular a multi-channel process data acquisition device, wherein the field device comprises a first server, preferably a first web server, wherein a data request from a first client, preferably a

Web client, for example. From an operating unit, is provided to the first server of the field device, wherein the data request is forwarded by means of the first server of the field device to a second, preferably external, web server, and the requested data from the second server, for example electronic database, retrieved and transmitted to the first server of the field device, wherein the retrieved data from the first server of the field device (subsequently) are transmitted to the client. The method is preferably used for operating the field device or for retrieving data relating to the field device or for understanding the settings or the mode of operation, or relating to the mode of operation of the field device

The field device is, for example, a sensor or an actuator or a multi-channel process data acquisition device. Furthermore, every process comes close

Component into consideration. The field device has an implemented first server, for example a web server - a server that uses the http or https protocol. The web server can, for example, be implemented in the firmware or a functional module which is operatively connected to the firmware, that is to say it can exchange this data. In this first server, it is also preferably a so-called. Proxy server over the

Connection to another server, for example. Said second, preferably external, server can be produced. A request to the first server, for example from a client, is therefore also addressed to this first server. The first server can now eg.

Check if he has queried the data in a storage unit that is in the

Field device is located, so finds an internal storage unit. If the requested data is present there, the server can transmit a corresponding response and / or the corresponding data itself to the client. The data can be transmitted between the client and the first server preferably in the form of telegrams. However, if the requested data does not exist in the field device, The first server can either process the request, for example make a protocol conversion and be forwarded, or it can forward the request directly to the second server. However, in both cases it may be necessary to address the data request to the other, second server. The client may be an application that is executed on the operating device and by means of which direct or indirect, for example by means of another application, queries can be made to the server on the field device.

The second server is preferably likewise a web server which is at least logically separated from the first server and preferably in communication with the first server via the Internet.

The data referred to by the data request from the client and located on the second server, or an associated storage device such as a

(electronic) database, are then retrieved from this storage unit and transmitted to the first server. From there, the retrieved data can be formatted or forwarded directly to the client. The first server in the

Field device is thus used as a mediator of the requests receives and then retrieves its own address from the second server. This can be done as described by a simple readdressing or processing of the data request.

Further, the data retrieved from the second server may be stored in the memory unit of the field device after being received by the first server.

Furthermore, a second data request may be made by the client through which further data is retrieved from the second server. This further data can then likewise be written into the memory unit of the field device. In particular, it can be provided that the data obtained by means of the first data request are overwritten and, for example, the data obtained by means of the second request are instead written into the memory unit.

The data received from the second server may be field device related data. For example. For example, a data request from the client may also be the execution of one or more arithmetic operations and the processing of data transmitted from the field device to the second server. Thus, it is possible to outsource data and functions of the field device and by means of the second server or associated data processing units

perform. In particular, one or more identifiers may be provided for the

Communication between the client, for example, on an operating device for

Operation of the field device is located, and the field device to be present. For a data request, an identifier is then transmitted from the client to the field device. The field device can then retrieve the information associated with this identifier from the second server. For this purpose, the identifier may be forwarded to the second server where the associated data is stored. As a result, at least the utilization associated with the data query of the

Communication link between the client and the field device and the field device and the second server can be reduced. For example, the identifier can consist of a numerical value. On the other hand, information associated with particular field device-related information on the field device can be linked to a parameter and its value by means of the indicator. As a result, if, for example, a parameter is called, the assigned identifier is transmitted to the second (external) server and the associated information is transmitted to the field device. The field device can then transmit this information to the operating device or the client application on it.

In this case, it is particularly advantageous if extensive data, which, for example, must also be kept in different languages, are stored in a paged out database

Storage unit that can be accessed through the second server to be outsourced. These data may be parameters or

Parameter names, error texts, help texts, menu names and in the identifier to one, preferably alphanumeric, in particular encrypted,

Parameter identification is. Furthermore, it may be one or more

Operating instructions or troubleshooting instructions.

It is also particularly advantageous that a plurality of field devices are connected to the second server or are connectable and have access to the second server. Thus, a central data management and data maintenance, for example by the manufacturer of

Field devices are performed. The data stored in an external storage device can then be edited or provided without each one

Field device needs updating. Furthermore, it becomes possible for a plurality of different clients to connect to the first server on the field device simultaneously or successively. Inquiries from these two clients can then be managed by the first server and the requested data can be transferred back to the respective clients. It may be provided in particular that a first request from the first client and a second request is made by the second client. In addition, the respective requests may include an identification of the respective client or operating device or user of the operating device used. This makes it possible, for example, that although the same identifier is used to obtain certain data or data of a particular content. However, due to the identification, for example, different

Parameter description or operating instructions, for example, in different languages, transferred.

In one embodiment of the method, the field device thus has an internal

Memory unit in which, for example, field device-related data, in particular in a first language, particularly preferably in a first number of different languages, are stored or stored. For example. For example, the field device may have a certain amount of data and information that the field device uses at the factory, i. before delivery to a customer.

In a further embodiment of the method, field-device-related data are stored in the external database, preferably in a second language, particularly preferably in a second number of different languages. In particular, these data may be editable and retrievable by a plurality of field devices, in particular field devices having a server or web server.

In a further embodiment of the method, after receiving the data request by the first server of the field device and before forwarding the data request to the external server, it is checked whether the requested data is present in the internal storage unit.

In a further embodiment of the method, in the event that the requested data is not stored in the device-internal memory unit, the request is forwarded to the external server.

In a further embodiment of the method, in the case that the requested data is / are stored in the internal memory unit, the requested data is read from the internal memory unit and transmitted to the client by means of the first server of the field device.

In a further embodiment of the method, the requested data is / are identified by an identifier, such as, for example, a unique numbering associated with the requested data. Corresponding indicators are, for example, in the field device and an operating device or an external database which can be accessed by means of the second server stored.

In a further embodiment of the method, the request includes this

Identifier.

In a further embodiment of the method, the data are parameters or parameter names, error texts, help texts,

Menu names and the identifier to one, preferably alphanumeric, in particular encrypted, parameter identification.

In a further embodiment of the method, the web server of the field device is in a first communication connection, for example via the Internet Protocol, with the web client is or is this first communication connection established, and wherein the web server of the field device in a second communication connection, for example the Internet Protocol, with the external web server is or is this second communication connection established, in particular without the external web server with the web client in a direct communication connection. In a further embodiment of the method, a plurality of web clients (sockets) are parallel to one another, preferably simultaneously, in a communication connection with the web server of the field device.

In a further embodiment of the method, a first request is made to the web server of the field device by a first of these multiple web clients, wherein a second request is made to the web server of the field device by a second of these several web clients, the first request being retrieved by retrieving data is answered from the field device internal memory unit, wherein the second request is answered by retrieving data from an external electronic database by means of the external server.

In a further embodiment of the method, wherein the external electronic database is a database to which, for example, the

Field device manufacturer has exclusive access.

In a further embodiment of the method, a plurality of field devices are in communication with the external web server and access to the electronic database via the external web server. With regard to the arrangement, the object is achieved by an arrangement comprising a field device with a web server, an external web server and a web client for carrying out the method according to one of the preceding embodiments. In particular, the arrangement can thus also comprise a plurality of field devices, each having a communication link with the external, second server.

The invention will be explained in more detail with reference to the following drawings. 1 shows a schematic representation of instruments and the control in an industrial plant,

2 shows a schematic representation of a field device. FIG. 1 shows a plurality of field devices F1, F2, F3, which are connected in a system via a field bus FB to a process controller C. In addition to the controller C is still a field bus access unit G, also called Gateway, connected to the fieldbus FB.

The process control arrangement P has a first bus system B1, which connects the units of the process control C. To the bus system B1, a first arithmetic unit is connected. The process controller C is used by a plant operator to control the system.

Via an interface of the control unit S, the first bus system B1 is connected to the fieldbus B1. The fieldbus FB may, for example, be a Profibus DP fieldbus to which field devices F1, F2, F3, RIO are connected. The fieldbus FB in turn is connected, for example via a segment coupler or here a so-called. Remote I / O RIO with the field devices F2, F3. Instead of one Profibus, another fieldbus such as HART or Fieldbus FF can be used.

In addition, a second bus system B2 is provided, on which in the shown

Embodiment, a computing unit RE2 is connected to the

Plant monitoring and / or visualization of data that are transmitted, for example, via the fieldbus FB, is used. The second bus system B2 forms a higher communication level to the fieldbus FB. The second bus system B2 may, for example, be a corporate network. Via the fieldbus access unit G, the field devices can be accessed from the second bus system B2, for example in order to operate them or to retrieve data from the field device F1, F2, F3. there enable operating programs such as plant asset management to diagnose and / or visualize the field devices F1, F2, F3.

In the process control arrangement P shown in FIG. 1, the in-house process

Process control system P separated from the corporate network with its bus system B2, d. H. the second bus system B2 is not directly connected to the first bus system B1. This can u. a. contribute to an increase in plant safety, since operation and thus influencing the process flow can be prevented by unauthorized users.

In order nevertheless to allow, for example, a query of a field device status of one of the field devices F1, F2, F3, the fieldbus interface G, for example, is provided via which the second bus system B2 is connected to the fieldbus. The fieldbus interface G thereby enables the connection of the second bus system B2 with the field devices F1, F2, F3. This enables communication between the higher-level second bus system B2 and the field devices F1, F2, F3.

The field devices F1, F2, F3 can be addressed, for example, via an addressing with which, for example, one or more telegrams are provided.

The fieldbus FB can thus be accessed via an interface of the control unit C as well as via the fieldbus interfaces G. Cyclic queries can be made by the control unit C and acyclic queries on the first fieldbus FB by the first fieldbus interface G. For example. Data from the fieldbus can be heard or transmitted via the fieldbus by the computer unit RE2 of the bus system B2 via the fieldbus interface G, in particular, for example.

Diagnostic information can be retrieved from one of the field devices F1, F2, F3.

Figure 2 shows a schematic representation of a field device, the example. In the plant acc. Figure 1 can be used. The field device may be, for example, a sensor with a sensor MA, is detected by a physical and / or chemical measured variable and converted into an electrical signal. This signal can be processed, for example, by means of a measured-value-processing logic, such as, for example, a microprocessor or a microcontroller. This logic can be part of a firmware Fl of the field device F in particular. The firmware F1 can also be connected to a web server C1. However, this web server can also be part of the firmware, ie integrated into it. This communication connection X3 can be, for example, a field-device-internal bus to which also a memory unit which is located in the Field device is arranged, is connected. It is also possible that the storage unit (only) can be accessed via the web server.

The field device can also have a, for example, wired, separate interface (for example, in addition to a fieldbus interface), via which the field device can be connected to an operating device. However, an interface for wireless data transmission, for example via radio, in particular WLAN, is also possible. In addition to the connection via Ethernet, wired or wireless, is also a connection via Bluetooth or a fieldbus system or an interface that gem. a fieldbus protocol is conceivable. Several requests, for example from different operating devices, can also be processed in parallel via such an interface.

For example. can u.a. for this purpose in the field device one or more

Be stored state machine, which ensured that not two operators simultaneously change data. The device can be accessed via several tools (eg FieldCare, Field Device Manager, Web server, external tools, ..). If several field devices, for example, read access to the external memory (database), there are no problems. The requests are processed one after the other. If several field devices or HMI devices attempt to write to the external memory (database), the corresponding authorization must first be checked. If the write permission exists, the data in the external database is changed and made available in a new query by the field device or the HMI device. The field devices are not informed that data has changed. Each client who accesses the field device is assigned a session ID, for example. If the maximum number of session ID, e.g. 10 users at the same time, reached, for example, a hint appears. This avoids that the device interrupts the measurement value registration by too many requests. The actual parameterization (changing the

Field device settings) can also, for example, be limited to a user.

An operation or generally a data exchange can then take place via an operating device which can be connected to a (communication) interface of the field device. This interface can then be used to operate the field device via the web server by means of the operating device.

A client, in particular a web client, can be provided on the operating device, which is, for example, a handheld operating device. Via this client, a user can transmit data to the field device or retrieve it from there via the server C1. For this purpose, the client can request a data via a corresponding interface of the Transferring the HMI device to the field device, the data request can be processed by the Web server C1 by either the requested data from the storage unit in which it may, for example, be a database can be retrieved and transmitted to the client. The data request can, for example, in the case that the requested data is not present in the memory unit S1 (or also generally) are forwarded to the server C2. For identification of the requested data can, for example, a

Identifier in the form of a numerical or other value.

The interface between the operating device BG and the field device F may be, for example, an Ethernet interface, in particular via an "RJ-45" or "RJ45" plug / socket.

The field device F can also have a further interface via which the field device can be in communication with the second, external server. This communication connection can also be an Ethernet connection. Preferably, this connection exists at least in part via the Internet. As a result, the server C2 can also be located far away from the field device F. It is also possible for the data request from the HMI device and the forwarding to the second (external) server from the first server to take place via the same (hardware-based) interface but, for example, via different data channels. The first server then acts as a kind of client for the second, external server, for example in the case of

Address mappings in which the request of the client on the HMI device to the second (external) server only the address (address mappings) is mapped to another address.

About this communication connection V2, the data request from the client on the HMI device can be forwarded to the server C2. In this case, a simple readdressing or even a protocol conversion can take place. It may, for example, be dependent on the protocols used for communication via the connections V1 and V2, respectively, if protocol conversion is required. For example. For example, the identifier transmitted from the client to the field device or the server C1 can be further transmitted to the server C2.

After reception, the server C2 can retrieve the requested data from the memory unit S2, which, for example, can also be a database. The data retrieved from the memory unit S2 can then be transmitted to the client via the connection V2 and via the server C1. This can also be a direct forwarding, a caching of the data from the database S2 and / or a readdressing or further processing by means of the firmware FL or another Data processing unit of the field device F done. The data thus requested by means of the data query of the client CL are then retrieved from the server C2 or the memory unit S2. In particular, it is thus possible for a plurality of field devices, which are, for example, in each case in a communication connection with the server C2, the data from the

Memory unit C2 to provide, without that in each of the field devices must be edited individually. Instead, it is sufficient to edit the memory unit S2 or the server C2. The data located in the storage unit S2 may, for example, be information that is the same information in different languages. It is also possible to provide user-specific settings remotely which otherwise would not have been accommodated in the limited memory unit S1. It is essential to save in the field device: The values of the parameters

Influence the measuring behavior (inputs) or the output (outputs). Here are the purely numerical values. This data can be stored in the field device, for example, together with one or more flags that serve as identifiers. This data can be stored, for example, in a separate memory area. The description of the data itself (parameter name, help text, ...) are only marked with an ID, a flag or another identifier. Based on this identifier, the firmware reads out the corresponding data in the set language. This can, as described above, be carried out by forwarding the data request from the HMI device to the second (external) server. The data associated with the identifier can then in turn be transmitted by the field device to the operating device or the client application on the operating device.

Due to the presence of a central database, which can be reached by the field device by means of the server thereon, changes can be made

field device-related data not only via the field device or the HMI device itself but e.g. also be carried out via an external application and then distributed centrally to various field devices.

Claims

claims

1. Method for operating a field device (F), in particular a multi-channel process data acquisition device,

wherein the field device (F) has a first server (C1), preferably a first web server,

wherein a data request from a first client (CL), preferably a web client, for example from an operating unit (BG), to the first server (C1) of the field device (F) is provided,

wherein the data request by means of the first server (C1) of the field device (F) to a second, preferably external, server (C2), for example, also a web server, forwarded, and the requested data from the second server (C2), eg. from an electronic database (S2), retrieved and transmitted to the first server (C1) of the field device (F),

wherein the retrieved data from the first server (C1) of the field device (F)

(subsequently) to the client (CL).

2. Method according to the preceding claim,

wherein the field device (F) has an internal memory unit (S1), in the example.

field device related data, in particular in a first language, more preferably in a first number of different languages are stored.

3. The method according to any one of the preceding claims,

wherein in a storage unit, for example. An external electronic database (S2) field device-related data, preferably in a second language, particularly preferably in a second number of different languages are stored.

4. Method according to one of the preceding claims,

wherein after receiving the data request by the server (C1) of the field device (F) and before forwarding the data request to the external server (C2) it is checked whether the requested data is present in the internal storage unit (S1).

5. Method according to one of the preceding claims,

wherein, in the case that the requested data is not stored in the device-internal storage unit (S1), the request is forwarded to the external web server (C2).

6. The method according to any one of the preceding claims,

wherein in the case that the requested data is stored in the internal storage unit (S1), the requested data is read from the internal storage unit (S1) and by means of the web server (C1) of the field device (F) to the client (CL) are transmitted.

7. The method according to any one of the preceding claims,

wherein the requested data is identified by an identifier, such as a unique numbering associated with the requested data.

8. Method according to the preceding claim,

wherein the request includes this identifier.

9. Method according to one of the preceding claims,

where the data are parameters or parameter names,

Error texts, help texts, menu names and the identifier is a, preferably alphanumeric, in particular encrypted, parameter identification.

10. The method according to any one of the preceding claims,

wherein the server (C1) of the field device (F) is in a first communication connection (X1), for example via the Internet Protocol, with the client (C1),

and wherein the server (C1) of the field device (F) in a second

Communication connection (X2), for example, also via the Internet Protocol, with the external server (C2),

in particular without the external server (C2) being in direct communication with the client (CL).

1 1. Method according to the preceding claim,

wherein several clients (sockets) are parallel to one another, preferably simultaneously, in a communication connection with the server (C1) of the field device (F).

12. Method according to the preceding claim,

wherein a first request is made to the web server (C1) of the field device (F) by a first of these multiple clients,

wherein a second request is made to the server (C1) of the field device (F) by a second of these multiple clients,

the first request being by retrieving data from the field device internal

Memory unit (S1) is answered,

wherein the second request is answered by retrieving data from an external storage unit (S2) via the external server (C2).

13. Method according to the preceding claim, wherein the external storage device is an electronic database to which the field device manufacturer has exclusive access.

14. Method according to the preceding claim,

wherein a plurality of field devices are in communication with the external server (C2) and have access to the memory unit C2 via the external server (C2).

15. Arrangement comprising a field device (F) with a server (C1), an external server (C2) and a client (CL) for carrying out the method according to one of the preceding claims.