Method for operating an automation technology field device by means of an operating unit

Abstract

The invention relates to a method for operating an automation technology field device (FG) by means of an operating unit (BE), comprising: - retrieving a code (CD) via the web server (WS) and loading the code (CD) onto the operating unit (BE); - retrieving a device driver or a device description (EDD) for the field device (FG) and loading the device driver or the device description (EDD) onto the operating unit (BE); - executing the code (CD) in a browser (BR) of the operating unit (BE), the executed code (CD) providing an interpreter for the device driver or the device description (EDD); - loading the device driver or the device description (EDD) into the interpreter; and - operating the field device (FG), and, during operation, one or more operating telegrams are generated by the device driver or the device description (EDD), wherein the operating telegrams are designed according to the field bus protocol and are transmitted from the operating unit (BE) to the web server (WS) in a manner tunneled via the second communication network, and / or, during operation, one or more reply telegrams are generated by the field device (FG) and are transmitted from the field device (FG) to the operating unit (BE) in a manner tunneled via the second communication network.

Description

[0001] Method for operating a field device in automation technology using an operating unit

[0002] The invention relates to a method for operating a field device of automation technology by means of an operating unit, wherein the field device has a web server and wherein the field device is designed for communication via a first communication network, wherein the first communication network is based on a protocol for a fieldbus of automation technology, wherein the operating unit is in communication connection with the web server via a second communication network.

[0003] Field devices are already known from the state of the art and are used in industrial plants. They are widely employed in process automation as well as in manufacturing automation. In principle, field devices are defined as all devices used close to the process that provide or process process-relevant information. Thus, field devices are used to acquire and / or influence process variables. Measuring instruments or sensors are used to acquire process variables. These are used, for example, for measuring pressure and temperature, conductivity, flow rate, pH, level, etc., and acquire the corresponding process variables such as pressure, temperature, conductivity, pH value, level, and flow rate. Actuators are used to influence process variables.These include, for example, pumps or valves that can influence the flow of a liquid in a pipe or the fill level in a container. In addition to the aforementioned measuring devices and actuators, field devices also include remote I / Os, radio adapters, and generally any devices located at the field level.

[0004] A large number of such field devices are produced and distributed by the Endress+Hauser Group.

[0005] In modern industrial plants, field devices are typically connected to higher-level units via communication networks such as fieldbuses (PROFIBUS®, FOUNDATION™ Fieldbus, HART®, etc.). These higher-level units are usually control systems (DCS) or automation systems, such as a PLC (programmable logic controller). The higher-level units are used, among other things, for process control, process visualization, process monitoring, and commissioning of the field devices. The measured values ​​acquired by the field devices, especially sensors, are transmitted via the respective bus system to one (or possibly several) higher-level unit(s). Data transmission from the higher-level unit to the field devices via the bus system is also necessary, particularly for configuring and parameterizing field devices and controlling actuators.

[0006] Mobile operating devices are frequently used to operate field devices (e.g., to configure parameters or retrieve data). These are connected to a field device either via cable (e.g., a service interface) or wirelessly (e.g., via Bluetooth). Examples of operating devices include laptops, mobile devices such as smartphones or tablets, or central asset management stations.

[0007] To operate field devices, appropriate operating programs (operating tools) are required. These run either independently on higher-level units or on mobile operating devices (Endress+Hauser FieldCare, PACTware, AMS Fisher-Rosemount, Siemens PDM) or are integrated into control room applications (Siemens PCS7, ABB Symphony, Emerson Delta V). The term "operating" encompasses, among other things, configuring the field device, updating the field device, and / or querying and visualizing process and / or diagnostic data from the field device. The operating programs use device drivers to create operating commands specific to the field device and to interpret response signals from the field devices. Examples of such device drivers are DTMs (Device Type Managers) or FDI packages.

[0008] Field devices with TCP / IP-based interfaces (which include fieldbuses such as PROFINET, EtherNet / IP, Modbus TCP) or dedicated (service) interfaces such as Wi-Fi or Bluetooth often have a web server. The operator can connect directly to the field device's web server using the control unit and configure the field device.

[0009] Developing the web server application is time-consuming, and it must be ensured that the functionality of the field device offered via the web server matches the functionality offered on the fieldbus interface.

[0010] Based on this problem, the invention aims to simplify the operation of a field device via a web server.

[0011] The task is solved by a method for operating a field device of automation technology by means of an operating unit, wherein the field device has a web server and wherein the field device is designed for communication via a first communication network, wherein the first communication network is based on a protocol for a fieldbus of automation technology, wherein the operating unit is in communication connection with the web server via a second communication network, comprising:

[0012] - Retrieving a code via the web server and loading the code onto the control unit;

[0013] - Retrieving a device driver or device description for the field device and loading the device driver or device description onto the operator unit;

[0014] - Execution of the code in a browser of the control unit, whereby the executed code provides an interpreter for the device driver or the device description;

[0015] - Loading the device driver, or device description, into the interpreter; and

[0016] - Operating the field device, whereby, in the course of operation, one or more operating telegrams are generated via the device driver or the device description, wherein the operating telegrams are designed according to the protocol of the fieldbus and are transmitted via the second communication network from the operating unit to the web server, and / or wherein, in the course of operation, one or more response telegrams are generated by the field device and transmitted via the second communication network from the field device to the operating unit.

[0017] This method enables the provision of identical operating functionality for a field device via its web server, just as with fieldbus operation. For this purpose, code and a device driver, or device description, are obtained from the web server. Executing this code in a browser on the operator unit provides an execution environment, or framework application, for the device driver or device description. This reduces development effort because the same device driver or device description required for fieldbus operation can be used. Furthermore, no operating program needs to be installed on the operator unit.

[0018] Common browsers such as "Chrome", "Firefox", "Edge", etc. can be used on the control unit.

[0019] Field devices mentioned in connection with the method according to the invention have already been described by way of example in the introductory part of the description.

[0020] One variant of the procedure involves the code and / or the device driver, or the device description, being located on the field device and being loaded from the field device to the operator unit via the communication network. For this purpose, the field device has a storage unit in which the code and / or the device driver, or the device description, is stored, for example, during the manufacturing of the field device. Operation of the field device can be "plug and play" if both the code and the device driver, or the device description, are stored on the field device.

[0021] A second variant of the procedure involves the code and / or the device driver, or the device description, being located on a server and being loaded from the server to the operator unit via a third communication network. The operator unit can then retrieve a link to the storage location of the code and / or the device driver, or the device description, on the server via the field device's web server and retrieve the code and / or the device driver, or the device description, by opening the link. Advantageously, this ensures that an up-to-date version of the code, the device driver, or the device description is always available.

[0022] Advantageously, a graphical user interface is retrieved and loaded onto the control unit in the same way as the device driver or device description, with the code providing an environment for the graphical user interface upon execution. This can be a single, shared code component. Alternatively, it may be necessary to provide additional code.

[0023] Advantageously, one implementation of the method provides for the use of WebAssembly bytecode. Bytecode is a collection of instructions in binary form. WebAssembly (WASM for short) enables the execution of this bytecode in web browsers. Programs can be defined using the bytecode and then executed in the browser.

[0024] Alternatively, the code can be based on JavaScript. In this case, it may be intended that the code was generated by an LLVM (formerly: "Low Level Virtual Machine")-to-web compiler, for example "emscripten".

[0025] According to one variant of the procedure, an Electronic Device Description (EDD), a General Station Description (GSD), an Electronic Data Sheet (EDS), or an IO-Link Device Description (IODD) is used as the device description. The exact type of device description is defined by the protocol of the first communication network.

[0026] It may further be provided that a user interface plugin (UIP) is used as the graphical user interface, which, together with the device description, is retrieved from the web server as an FDI device package and loaded onto the operator panel. According to an advantageous embodiment of the method, an EDD interpreter or an ODD interpreter may be used as the interpreter.

[0027] Another variant of the procedure involves using a Device Type Manager as the device driver. For example, this allows the implementation of the "FDT Server" concept, which is defined in the Field Device Tool Specification version 3.0. The core server resides in the device along with the web server. When operated via the control unit, the core server can be executed as code on the control unit and, for example, be designed according to WASM.

[0028] According to an advantageous embodiment of the method, it is provided that the browser is executed in a frame application running on the control unit, in particular a Field Device Tool frame application.

[0029] It may be possible for the browser to execute an extension or plugin that saves data contained in the response telegrams, particularly parameter data from the field device. This allows data sent by the field device, especially parameters, to be easily saved in the control unit.

[0030] One embodiment of the procedure provides that a computer unit, in particular a PC or laptop, or a mobile device, in particular a tablet or smartphone, is used as the operating unit.

[0031] One embodiment of the method provides that a wired communication network or a wireless network, in particular based on Bluetooth, Bluetooth LE, or WiFi, is used as the second communication network. The first communication network is, in particular, a fieldbus used in automation technology (for example, HART, Profibus, FOUNDATION™ Fieldbus, 10-Link, or an Ethernet-based fieldbus, for example, PROFINET). The third communication network is, in particular, the Internet. The invention is explained in more detail with reference to the following figure. It shows

[0032] Fig. 1 : a schematic representation of a first embodiment of the method according to the invention.

[0033] The procedure concerns the operation of a field device (FG) using an operating unit (BE). The field device (FG) is, for example, a measuring or control device that has one or more sensor or actuator units for acquiring or influencing a physical, chemical, or biological quantity of a process, particularly in process engineering. The field device (FG) is connected to a first communication network, which is a fieldbus. This fieldbus is, in particular, a fieldbus based on one of the protocols HART, Profibus PA / DP, FOUNDATION™ Fieldbus, or IO-Link. However, it can also be an Ethernet-based fieldbus, such as PROFINET.

[0034] The field device FG can also be a network device, for example a gateway or an edge device, which is integrated into the first communication network.

[0035] The control unit BE is a laptop or a mobile device, in particular a smartphone or a tablet.

[0036] To operate the field device FG using the control unit BE, a communication connection is established between the control unit BE and the field device FG in process step 1. The field device FG has a web server WS for this purpose, to which the control unit BE connects via a second communication network. This second communication network is either a wired communication network (for example, based on Ethernet, USB, or a proprietary solution such as CDI) or a wireless network, in particular based on Bluetooth, Bluetooth LE, or WiFi. The web browser WS contains a website WB, the content of which is loaded onto the control unit BE via the established communication connection in process step 2. The website WB is executed in a browser BR on the control unit BE. The user can initiate the operation of the field device FG via the website WB.Initiating the operation, for example by clicking a button on the website WB, opens a link that points to a code CD. In this embodiment, the code CD is stored on the field device FG. In a third process step (3), the link to the code CD is opened and a request is sent to the web server WS.

[0037] In process step 4, the code is loaded onto the operator unit BE. The code CS is a WebAssembly bytecode. This code CD is loaded into the operator unit BE's browser BR and executed by it. This executes an interpreter contained in the code CD. Specifically, this interpreter is an EDD interpreter. Furthermore, executing the code CD opens another link that points to an FDI device package PK stored on the field device FG.

[0038] In process step 5.), a request is sent to the web server WS and in process step 6.), the FDI device package PK is loaded onto the operating unit.

[0039] The FDI device package PK contains a device description EDD and a graphical user interface UIP. Both components are loaded into the interpreter.

[0040] To operate the field device FG, the user is now shown the graphical user interface, which allows them to initiate operating actions. For example, the user might want to read parameter values ​​of the field device FG as an operating action. The user selects this operating action on the interface. The program executed by code CD then creates an operating telegram BT, which is transmitted to the field device FG in process step 7. The operating telegram uses, for example, an HTTP(S) request with JSON or another data format. The content of the JSON is the operating action in the format of the fieldbus protocol of the first communication network. The operating action is thus tunneled into the JSON telegram.

[0041] The field device's web server (WS) contains a tunnel service (TS) that unpacks the operator telegram (BT). After unpacking, the operator action present in the fieldbus protocol is processed by a fieldbus service (FS) of the field device (FG) and fed to an application (AP) of the field device (FG). The fieldbus service uses ISO / OSI Layer 7 to process the operator action.

[0042] The operator action is then processed by the application AP. The application provides the requested parameter values. In reverse order of the process described, a response telegram AT is created, containing the response in a fieldbus protocol format. This response is tunneled into JSON and transmitted to the operator unit BE. The interpreter unpacks the contents of the response telegram and displays the parameter values ​​using the device description. The browser BR may contain a plugin that allows the parameter values ​​to be saved. The device description EDD is specifically tailored to the type of fieldbus. For example, an Electronic Device Description, a General Station Description, an Electronic Data Sheet, or an I / O Device Description can be used as the device description. A device driver in the form of a DTM can also be used.

[0043] Accordingly, the device package PK can be designed in a different format than an FDI device package. Instead of a complete device package, only the device description or the device driver can be loaded directly.

[0044] It may be possible to electronically sign the device package PK or its components to increase security. The signature is created by the field device manufacturer, who provides the user with a public key. Using this public key, the signature can be verified, confirming that the device package PK is intended for the field device FG.

[0045] Alternatively, the code CD and / or the FDI device package can be located on a server instead of on the field device FG. The link then points to the storage location on the server, which can be accessed by the operator unit BE via a third-party communication network, in particular the internet.

[0046] Reference symbol list

[0047] 1.), 2.), 7.) Procedural steps

[0048] AP Application AT Response Telegram

[0049] BE control unit

[0050] BR Browser

[0051] BT operating telegram

[0052] CD Code EDD Device Description

[0053] FG Field Device

[0054] FS Fieldbus Service

[0055] PK (FDI) device package

[0056] TS Tunnel Service UIP Graphical User Interface

[0057] WB Website

[0058] WS Webserver

Claims

Patent claims 1. Method for operating a field device (FD) of automation technology by means of an operating unit (UU), wherein the field device (FD) has a web server (WS) and wherein the field device (FD) is designed for communication via a first communication network, wherein the first communication network is based on a protocol for a fieldbus of automation technology, wherein the operating unit (UU) is in communication connection with the web server (WS) via a second communication network, comprising: - Retrieving a code (CD) via the web server (WS) and loading the code (CD) onto the control unit (BE); - Retrieving a device driver or device description (EDD) for the field device (FG) and loading the device driver or device description (EDD) onto the operator unit (BE); - Execution of the code (CD) in a browser (BR) of the control unit (BE), wherein the executed code (CD) provides an interpreter for the device driver or the device description (EDD); - Loading the device driver, or the device description (EDD), into the interpreter; and - Operating the field device (FG), wherein, in the course of operation, one or more operating telegrams are generated via the device driver or the device description (EDD), wherein the operating telegrams are designed according to the protocol of the fieldbus and are transmitted via the second communication network from the operating unit (BE) to the web server (WS), and / or wherein, in the course of operation, one or more response telegrams are generated by the field device (FG) and transmitted via the second communication network from the field device (FG) to the operating unit (BE).

2. The method of claim 1, wherein the code (CD) and / or the device driver, or the device description (EDD), is located on the field device (FG) and is transmitted via the The second communication network is loaded from the field device (FG) to the control unit (BE).

3. Method according to claim 1, wherein the code (CD) and / or the device driver, or the device description (EDD), is located on a server and is loaded from the server to the operating unit (BE) via a third communication network.

4. Method according to claim 3, wherein the operating unit (BE) retrieves a link to the storage location of the code (CD) and / or the device driver, or the device description (EDD), on the server via the web server (WS) of the field device (FG) and retrieves the code (CD) and / or the device driver, or the device description (EDD), from the server by opening the link.

5. Method according to one of the preceding claims, wherein, in addition and in the same way as the device driver or the device description (EDD), a graphical user interface (UIP) is retrieved and loaded onto the operating unit (BE), wherein the code (CD) provides an environment for the graphical user interface (UIP) when executed.

6. Method according to any of the preceding claims, wherein a WebAssembly bytecode is used as the code (CD).

7. Method according to any one of claims 1 to 5, wherein the code (CD) is based on JavaScript.

8. Method according to any of the preceding claims, wherein the device description (EDD) used is an Electronic Device Description, a General Station Description, an Electronic Data Sheet, or an IO Link Device Description.

9. Method according to claims 8 and 5, wherein a user interface plugin is used as the graphical user interface (UIP), which is used together with the device description. (EDD) is retrieved as an FDI device package from the web server (WS) and loaded onto the operator unit (BE).

10. Method according to claim 8 or 9, wherein an EDD interpreter or an ODD interpreter is used as the interpreter.

11. Method according to any one of claims 1 to 7, wherein a Device Type Manager is used as the device driver.

12. Method according to claim 11, wherein the browser (BR) is executed in a frame application, in particular a Field Device Tool frame application, executed on the control unit (BE).

13. Method according to one of the preceding claims, wherein the browser (BR) executes an extension or plugin which stores data contained in the response telegrams, in particular parameter data of the field device (FG).

14. Method according to one of the preceding claims, wherein a computer unit, in particular a PC or a laptop, or a mobile terminal, in particular a tablet or smartphone, is used as the control unit (CU).

15. Method according to one of the preceding claims, wherein a wired communication network or a wireless network, in particular based on Bluetooth, Bluetooth LE or WiFi, is used as the second communication network.

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