Configuration-free output of user data contained in Ethernet telegrams

Description

[0001] The invention relates to a device for extracting user data from Ethernet telegrams transmitted by a field device. Furthermore, the invention comprises a system comprising a device according to the invention.

[0002] Field devices used in industrial plants are already known from the state of the art. Field devices are widely used in automation technology as well as in manufacturing automation. Field devices essentially refer to all devices used close to the process and that provide or process-relevant information. Field devices represent a subclass of the term "sensor systems." Field devices are used to record and / or influence process variables. Sensor systems are used to record process variables. These are used, for example, for pressure and temperature measurement, conductivity measurement, flow measurement, pH measurement, level measurement, etc., and record the corresponding process variables such as pressure, temperature, conductivity, pH value, level, flow, etc. Actuator systems are used to influence process variables.These include, for example, pumps or valves that can influence the flow of a fluid in a pipe or the fill level in a container. In addition to the previously mentioned measuring devices and actuators, field devices also include remote I / Os, wireless adapters, and generally devices located at the field level.

[0003] DE 10 2013 112875 A1 discloses an adapter system with field devices.

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

[0005] The measured values ​​acquired by the field devices, especially sensors, are transmitted via the connected bus system to one or, if necessary, to several higher-level units. Data transmission from the higher-level unit to the field devices via the bus system is used primarily for configuring and parameterizing field devices or for diagnostic purposes. Generally speaking, the field device is operated or controlled by the higher-level unit via the bus system. The power supply to the field devices connected to a fieldbus, in which the corresponding bus protocol is implemented, is also provided via the respective fieldbus.

[0006] A disadvantage of the fieldbuses commonly used in automation technology is their relatively low transmission rates. As field devices become increasingly complex in their functionality, this leads to long transmission times, particularly in the case of parameterization and configuration, but also in the case of transmitting large amounts of measurement data from the field device to the control unit, which is obviously disadvantageous for the customer, i.e., the operator of the process plant.

[0007] Therefore, it has become common practice in automation technology to transmit data between the control level and the field level, or vice versa, via an Ethernet data line. This provides a direct Ethernet connection to the field devices, as well as to the other participants in the bus system (controllers, remote I / Os, etc.).

[0008] The process variables recorded by the field device are transmitted via the Ethernet data line to the plant's control center, where they are processed. There are no plans to make the recorded process variables directly visible in the field.

[0009] Based on this problem, the invention is based on the object of making user data of a field device, which is transmitted via Ethernet telegrams, visible at the field level of a system.

[0010] The object is achieved by a device according to claim 1 and by a system according to claim 7.

[0011] With regard to the device, a device for extracting user data from Ethernet telegrams sent by a field device is provided, comprising: An input interface and an output interface for connection to an Ethernet data line, wherein the input interface is configured to receive Ethernet telegrams transmitted via the Ethernet data line; an electronic unit configured to evaluate the received Ethernet telegrams and to extract a value of at least one process variable from the payload data portions of the received Ethernet telegrams; and an output unit for outputting the determined process variables.

[0012] The device according to the invention enables the output of user data from field devices at the field level of the system. According to the invention, the user data comprises values ​​of process variables, measured value status, and diagnostic information. For this purpose, the device reads Ethernet telegrams sent over an Ethernet data line and determines the values ​​of the process variables from the Ethernet telegrams. The device does not need to be announced or addressed in the Ethernet network, thus representing a plug-and-play component.

[0013] According to the device according to the invention, it is provided that the device further comprises: a memory unit, wherein the memory unit comprises a database with device description data of a plurality of field device types, wherein the device description data comprises information for interpreting the payload data portions of the field devices, in particular the data type and / or the payload data length.

[0014] According to the device according to the invention, the electronics unit is designed to determine the structure of the process variables to be determined based on similarities between the payload portion of the Ethernet telegrams and information stored in a database for interpreting the payload portions. Different field devices sometimes use different formats for the value of the process variables in an Ethernet telegram, which is why the device must be configured for the corresponding field device. By storing the device descriptions of various devices in the memory unit, the device is able to independently determine the form of the payload portion in the telegram and how it can be interpreted.In its simplest form, the device's electronics unit compares the payload portion of the Ethernet telegram with the entries in the database in a table, thereby obtaining information for interpreting the payload portion. A more complex alternative involves the electronics unit using an AI ("artificial intelligence") algorithm, which determines similarities between the payload portion of the Ethernet telegrams and information stored in the database, thereby obtaining information for interpreting the payload portion.

[0015] According to an advantageous embodiment of the device according to the invention, the output unit is a display unit, in particular a display designed to display the determined process variables. For example, a 7-segment display is used.

[0016] Alternatively, the output unit is a further interface, in particular a radio interface, via which the process variable can be called up in a protocol different from the Ethernet protocol used, in particular from an operating unit.

[0017] According to an advantageous development of the device according to the invention, the device has an internal connection between the input interface and the output interface, wherein the internal connection is designed to forward the Ethernet telegrams arriving at the input interface to the output interface without loss. In the simplest case, this is an electronic connection, for example, a metal wire connection or a connection on a circuit board. The Ethernet data line is thus extended by this connection, so that the Ethernet telegram is passively passed through the device between the input interface and the output interface. Alternatively, the device "stops" the Ethernet telegram, i.e., receives it without passively forwarding it, then evaluates it, and actively retransmits it to the receiver.

[0018] According to an advantageous embodiment of the device according to the invention, the internal connection has a tap connected to the electronics unit. This tap allows the electronics unit to read the Ethernet telegram without modifying the Ethernet telegram itself or changing the data traffic on the Ethernet data line.

[0019] With regard to the system, it is intended that the system shall include: A device according to the invention; a field device in automation technology, wherein the field device is designed to record at least one process variable of a process engineering process; a higher-level unit; and an Ethernet data line, wherein the Ethernet data line consists of a first segment and a second segment, wherein the first segment connects the output interface of the device to the higher-level unit and wherein the second segment connects the field device to the input interface of the device, wherein the field device is designed to create Ethernet telegrams containing a value of the recorded process variable and to transmit them to the higher-level unit via the Ethernet data line.

[0020] The device according to the invention is therefore installed in an Ethernet data line between the higher-level unit and the field device. Such an Ethernet data line connects exclusively a single field device to the higher-level unit. Therefore, the device does not need to be configured with respect to the field device, for example, with respect to the field device's network address. A separate device is intended for each Ethernet data line.

[0021] According to a first advantageous variant of the system according to the invention, it is provided that the higher-level unit or a separate energy module is designed to supply the device and the field device with electrical energy via the Ethernet data line.

[0022] According to an advantageous embodiment of the first variant of the system according to the invention, it is provided that the Ethernet data line is a Power over Ethernet data line, in particular an EtherNet / IP, PROFINET, Modbus TCP or HART-IP data line.

[0023] According to a preferred embodiment of the first variant of the system according to the invention, it is provided that the higher-level unit is a switch or a power switch.

[0024] According to a second advantageous variant of the system according to the invention, it is provided that the system further comprises an energy module which is independent of the Ethernet data line and which is designed to supply the device with electrical energy.

[0025] According to an advantageous embodiment of the second variant of the system according to the invention, it is provided that the higher-level unit is a controller.

[0026] The invention is explained in more detail with reference to the following figures. Fig. 1 : several embodiments of the device according to the invention; and Fig. 2 : a schematic structure of an Ethernet telegram.

[0027] In Fig. 1 This diagram shows a network in an automation system. The network consists of a PLC control unit, higher-level (network) units 400, 400', field devices FG1, FG2, FG3, FG4, FG5, and an Ethernet data line 200 connecting these components (PLC, 400, 400' FG1, FG2, FG3, FG4, FG5). The Ethernet data line 200 conforms to an Industrial Ethernet standard, such as Profinet, Ethernet / IP, Modbus TCP, etc. Such a data line enables distances of up to 100 m between the individual devices using a copper cable. The individual devices (PLC, 400, FG1) require their own power supply.

[0028] The data line 200 of the higher-level unit 400 to the field device FG1 is divided into a first segment 210 and a second segment 220. The first segment 210 connects the higher-level unit 400 to a device 100 according to the invention. The second segment 220 connects the device 100 according to the invention to the field device FG1. The device has an input interface 210 for connecting to the second segment 220 and an output interface for connecting to the first segment 210.

[0029] The device 100 has an internal connection 160 between the input interface 110 and the output interface 120. This connection is designed such that telegrams transmitted from the field device FG1 to the higher-level unit 400, or vice versa, can be transmitted through the device without loss. Therefore, neither the higher-level unit 400 nor the field device FG1 "notice" that the device is located in the data line 200 connecting the higher-level unit 400 to the field device FG1.

[0030] Via a tap 161, the device is able to listen to the telegrams 300 exchanged between the field device FG1 and the higher-level unit 400. For this purpose, the device 100 has an electronic unit 130, e.g., an ASIC or a microprocessor, designed for this purpose. The electronic unit 130 has implemented an algorithm or a program that serves the purpose of analyzing the listened telegrams 300 and extracting the payload portion 310 from the telegrams.

[0031] A typical telegram structure of an Ethernet telegram 300 is shown in Fig. 2shown. After an introductory telegram part, the payload portion 310 begins. The electronics unit 130 is particularly designed to recognize the "Data" data portion of the payload portion 130. This contains, in particular, the values ​​of the process variables, measured value status, and / or diagnostic information acquired by the field device FG1. However, this data portion depends on the type and / or manufacturer of a field device and fluctuates, in particular, in data size and / or structure, in particular also depending, for example, on the type of acquired process variable.

[0032] The electronics unit 130 is therefore configured, by means of the implemented program or algorithm, to determine the structure of the data portion and the data to be extracted from it based on similarities between the payload portion of the Ethernet telegrams 300 and information stored in a memory unit 150 of the device for interpreting the payload portions. By storing the device descriptions of various devices in the memory unit 150, the device is able to independently determine the form in which the payload portion is present in the telegram 300 and how it can be interpreted. In the simplest form, it can be provided that the electronics unit of the device compares the payload portion of the Ethernet telegram 300 in a table with the entries in the memory unit 150 and thereby obtains information for interpreting the payload portion.A more complex alternative provides that the electronics unit 130 uses an AI ("Artificial Intelligence") algorithm, which determines commonalities between the payload data portion of the Ethernet telegrams and information stored in the memory unit 150, thereby obtaining information for interpreting the payload data portion.

[0033] The read and interpreted payload data portion is then output or reproduced by an output unit 140 of the device 100. In the simplest case, the output unit 140 is a display unit, in particular a display, which is designed to display the interpreted payload data portion, in particular the value of the process variable. For example, a 7-segment display is used.

[0034] Alternatively, the output unit 140 is a further interface, in particular a radio interface, via which the process variable can be retrieved in a protocol different from the Ethernet protocol used, for example Bluetooth or WiFi, in particular from an operating unit.

[0035] A section of the Ethernet data line (this section is designated 200') uses an Ethernet standard different from the Ethernet data line 200, for example, a standard compliant with IEEE 802.3 (10 BASE-TIL) / IEC 60079 (expected to be fully specified by the end of 2019). This allows power to be supplied to the field devices via the Ethernet data line (Power over Ethernet). Specifically, the data lines 200' outgoing from the higher-level unit 400' are designed to transport electrical power to the devices FG2, FG3, FG4, FG5, and 100'. For this purpose, the higher-level unit 400' is connected to an external power module 500'. The external energy module supplies both the higher-level unit 400' directly and the participants FG2, FG3, FG4, FG5, 100' via the data lines 200' with the electrical energy required for operation. List of reference symbols

[0036] 100Device 110Input interface 120Output interface 130Electronics unit 140Output unit 150Storage unit 160Internal connection 161Tap 200Ethernet data line 210First segment 220Second segment 300Ethernet telegrams 310Payload data portion 400Higher-level unit 500, 500'Energy module FG1, FG2, FG3, FG4, FG5Field devices PLCControl unit

Claims

1. A device (100) for extracting useful data from Ethernet telegrams transmitted by a field device (FG1, FG5), comprising: - an input interface (110) and an output interface (120) for connection to an Ethernet data line (200), the input interface (110) being designed to receive Ethernet telegrams (300) transmitted via the Ethernet data line (200); - an electronic unit (130) configured to evaluate the received Ethernet telegrams (300) and to extract a value of at least one process variable from the payload portions (310) of the received Ethernet telegrams (300); - a memory unit (150), the memory unit (150) comprising a database with device description data of a multiplicity of field device types, the device description data comprising information for interpreting the user data portions (310) of the field devices (FG1, FG5), in particular the data type and / or the user data length, wherein the electronic unit (130) is configured to determine the structure of the process variables to be determined on the basis of similarities of the user data portion (310) of the Ethernet telegrams (300) with information stored in the database for interpreting the user data portions (310); and - an output unit (140) for outputting the determined process variables.

2. A device (100) according to claim 1, wherein the output unit (140) is a display unit, in particular a display, which is configured to display the determined process variables.

3. device (100) according to claim 1 or 2, wherein the device (100) has an internal connection (160) of the input interface (110) to the output interface (120) wherein the internal connection (160) is configured to forward the Ethernet telegrams (300) incoming at the input interface (110) to the output interface (120) without loss.

4. A device (100) according to claim 3, wherein the internal connection (160) has a tap (161) connected to the electronic unit (130).

5. A system comprising: - a device (100) according to at least one of claims 1 to 6; - a field device (FG1, FG5) of automation technology, the field device (FG1, FG5) being configured to detect at least one process variable of a process engineering process; - a higher-level unit (400); and - an Ethernet data line (200), wherein the Ethernet data line (200) comprises a first segment (210) and a second segment (220), wherein the first segment (210) connects the output interface (120) of the device (100) to the higher-level unit (400) and wherein the second segment (220) connects the field device (FG1, FG5) to the input interface (110) of the device (100), wherein the field device (FG1, FG5) is configured to create Ethernet telegrams (300) containing a value of the detected process variable and to transmit the same to the higher-level unit (400) via the Ethernet data line (200).

6. System according to claim 5, wherein the higher-level unit (400) or a separate power module (500) is configured to supply the device (100) and the field device (FG1, FG5) with electrical energy via the Ethernet data line (200).

7. System according to claim 6, wherein the Ethernet data line (200) is a Power over Ethernet data line, in particular an EtherNet / IP, PROFINET, Modbus TCP or HART-IP data line.

8. System according to one of claims 6 or 7, wherein the higher-level unit (400) is a switch or a power switch.

9. System according to claim 5, comprising a power module (500') independent of the Ethernet data line (200), which is configured to supply the device (100) with electrical energy.

10. System according to claim 9, wherein the higher-level unit (400) is a controller.