Method for updating device descriptions for field devices in process automation technology

The invention relates to a method for updating device descriptions for field devices of the process automation technology according to the preamble of claim 1.

In the field of process automation technology, field devices are frequently used for recording and influencing process variables. Examples of field devices are temperature measuring devices, which measure the temperature of a process medium, flow meters which detect the flow of a process medium in a pipeline section or fill level meters which detect the fill level of a liquid or a bulk material in a container.

The field devices are generally connected via a data bus to superordinate control units, eg process control systems PLS or engineering system, from which the process sequence is controlled or monitored and direct access to individual field devices is also possible. Direct access to the field device can be used to change settings on the field device from the control unit or to call diagnostic functions of the field device. The measured values ​​of the various sensors are evaluated or monitored in the control unit and the corresponding actuators are controlled for process control. Data transmission between field device and control units is carried out according to known international standards for fieldbuses such as HART®, Foundation Fieldbus®, Profibus® or CAN-Bus®, etc.

Frequently, field devices from different manufacturers are used in process automation technology. The field devices are operated by means of PC-based applications which, in particular, support the parameterization, commissioning and diagnosis of individual field devices, in some cases also graphically.

Examples of such display and operating programs are AMS® from Fisher-Rosemount, Simatic PDM® from Siemens, Smart Vision® from ABB, VVO® from Vega or Commuwin® II from Endress + Hauser.

In order to enable the operation of different field devices from a control unit, the functionality of the respective field device must be known to the control device. The functionality of the field device is described by the so-called device description (Device Descriptions DDs). For this purpose, a special language, the Device Descriptions Language DDL, is available. By means of this standardized language, the necessary information about the functionality of a particular field device can be made available to other bus subscribers, in particular to the control system or a further operating device (handheld). As a rule, the device descriptions are generated by the field device manufacturer and delivered with the respective field device eg by floppy disk.

When the field device is put into operation, the corresponding device description is then installed from the application program.

The problem here is that device descriptions are partly updated by the manufacturer. The current device descriptions (updates) must then be sent to the corresponding user and then installed manually by means of the application program.

This method does not ensure that the user has the current device description in use. Particularly in the case of safety-relevant process applications, it is absolutely necessary that the user has the latest device description, especially when programming errors (bugfixing) have occurred in a device description version.

In the printed copy <patcit id="pcit0001" dnum="US20020004370A1"><text>US 2002/0004370 A1</text></patcit> A field device of the process automation technology is described in which a control device for the field device is provided as a separate portable unit. The field device and the control device communicate via a radio link. Software changes of the software of the field device can be loaded by the control device via the Internet and then transmitted to the field device.

The print <patcit id="pcit0002" dnum="WO0239638A2"><text>WO 02/39638 A2</text></patcit> Describes a method in which several computer units connected to the Internet form a user group, and each user releases specific data on his computer unit for access by other users.

In the printings <patcit id="pcit0003" dnum="US6047222A"><text>US 6,047,222</text></patcit> and <patcit id="pcit0004" dnum="DE10029448A1"><text>DE 100 29 448 A1</text></patcit> Fieldbus systems are described in which at least one field device is connected to at least one control unit via a communication link. The print<patcit id="pcit0005" dnum="EP0989713A2"><text>EP 0 989 713 A2</text></patcit> Relates to a method for updating Internet access devices.

The object of the present invention is to provide a method for updating device descriptions for field devices in the process automation system, which does not have the above-mentioned disadvantages, which in particular enable a simpler and secure updating.

This object is achieved by the method specified in claim 1.

The essential idea of ​​the invention is to store device descriptions for field devices on a central server, and that an application program in a control unit, which requires corresponding device information for operating a field device, loads it from the server after querying the device type of the field device.

Advantageous further developments of the invention are given in the subclaims.

The invention is explained in more detail below with reference to an exemplary embodiment shown in the drawing. Show it:<ul><li>FIG. 1 shows a process automation system in a schematic representation.</li></ul>

1 shows a process automation system with several field devices F1, F2, F3, which are connected to a company network via a data bus and a gateway G. FIG. The field devices F1, F2, F3 can be, for example, pressure meters, temperature meters or flow meters, etc. In addition to the field devices, a remote IO is also connected to the data bus. HART® field devices can be connected to the data bus D via the remote IO. The data bus D can be, for example, a Foundation Fieldbus® H1 bus. The company network F operates, for example, according to the Ethernet standard (TCP / IP protocol). Two computers (eg workstations or PCs) PC1 and PC2, which are used for controlling, engineering or monitoring the process plant, are connected to the company network F as control units. Furthermore, the company network F is connected to a firewall IS, which communicates with a remote server S via the Internet I.

The method according to the invention is explained in more detail below. If, for example, a special application, such as for operating, configuring, parameterizing or diagnosing a field device F1, F2, F3, which requires device descriptions (device descriptions) for field devices, is sent to a control unit, eg computer PC1, Application program sends a request to the field device to be operated, eg F1, and asks the device type of this field device. If the application program in the control unit does not contain the information required for this particular field device F1 or not in the current version, the necessary device descriptions are downloaded via the Internet from the server S on which the most recent device descriptions are stored.

This means that the latest device information is always available in the application program. In order to avoid unnecessary data transfer, the current device information is only loaded by the server S when the device information stored in the control unit PC1 differs from the memory information stored in the field device F1. This is the case, in particular, during the commissioning of the field device since, at this time, no information about this field device is yet stored in the control unit PC1.

Because device descriptions can change over time due to updates and bug fixes, the application program periodically sends requests to the server S to see if changed device descriptions are available.

In a simple manner, the connection between the control unit PC1 or PC2 and the server S is made via the Internet I via the firewall IS.

The connection between control unit PC1 and field device F1 is effected via a data bus D. The display and operating program of the company,

Endress + Hauser CommuWin II® permits a graphical device parameterisation which provides device diagnostics with error code and text explanation as well as the device operation. Device Descriptions DDs are required as device descriptions for this application.

Advantageously, therefore, the device descriptions are device descriptions DD to the field devices F1, F2, F3

Since it is not only possible to change device descriptions over time, but also firmware for specific field devices, it is also useful to load the current firmware from server S.

By requesting the application program to the server S, specific information from different field devices and different field device users is transmitted to the server S. These can be temporarily stored in the server S for statistical purposes. It is certainly very advantageous for the user if the updated device description or the current firmware is installed automatically.

A further advantage of the method according to the invention is that preconfigured device descriptions for special applications of a field device are stored in the server S and, after corresponding selection, are loaded by the user from the application program. This makes the parameterization of field devices considerably easier. In part, application programs (eg ToF-Tool® by Endress + Hauser) also use the corresponding language.

In a simple way, the device descriptions are stored in the respective country language. This provides the user with the required information in his country language and translates errors easily.

By means of the method according to the invention, it is ensured that the most recent device descriptions are always available to an application program.