DE102022114170A1 - Field device - Google Patents

Abstract

The invention relates to modular field devices (1) with high data transmission rates, which can be designed to conform to explosion protection. For this purpose, the electronic modules (10, 11, 13, 16) of the field device (1) are each connected to one another in series via data lines (12, 14, 17), so that explosion protection is not required for each individual module (10, 11, 13, 16 ) a separate power limitation device (15) is required. A virtual channel (CH1-CH7) is defined between each of the modules (10, 11, 13, 16), so that each of the modules (10, 11, 13, 16) is connected to every other module (10, 11, 13 ) each shares a common channel identification (IDCHx). This makes it possible for all electronic modules (11) that are not arranged in series at the "end" to forward incoming data packets ([IDCHx; data]) to the other internal interface (111, 112, 113) of the respective module (11) with as little decoding as possible, provided that the first electronic module (11) does not share the corresponding channel identification (IDCHx) of the incoming data packet ([IDCHx; data]) with one of the other modules (10, 13, 16). This enables a high data transfer rate despite the serial connection of the modules (10, 11, 13, 16).

Description

The invention relates to a modular field device that can work with a high data transmission rate and can still be designed to comply with explosion protection.

In automation technology, for example in large industrial process plants, field devices are often used that are used to record the relevant process parameters of process media. Suitable measuring principles are used to record the process parameters. Corresponding sensors are used, among other things, in point level measuring devices, level measuring devices, flow measuring devices, pressure and temperature measuring devices, pH redox potential measuring devices, conductivity measuring devices, etc. They record the respective process parameters in the containers or pipes in which the process medium is located, such as the fill level, flow, pressure, temperature, pH value, redox potential, conductivity or dielectric value. A large number of these field devices are manufactured and sold by Endress + Hauser.

Field devices are increasingly being designed modularly. This means that different types of field devices, such as pressure measuring devices, point level measuring devices or level measuring devices, are partly constructed with identical electronic modules. This is particularly advantageous in the case of those electronic modules that perform higher-level functions such as communication or measurement data processing. Those electronic modules that take on sensor-specific tasks must in turn be designed depending on the specific field device type. Overall, a modular design can achieve a significant cost reduction in the development and production logistics of new types of field devices.

• - UART- (Universal Asynchronous Receiver Transmitter"),
• - SPI- („Serial Peripheral Interface“), oder des
• - CDI- („Common Data Interface")

Protokolls. Extern wird beispielsweise mittels

• - USB („Universal Serial Bus“),
• - „Bluetooth“
• - LAN („Local Area Network“)
• - „PROFIBUS“ oder
• - „(Wireless) HART“

kommuniziert. Dabei werden die einzelnen Module über die entsprechenden Datenleitungen in der Regel außerdem mit Leistung versorgt.On the one hand, the individual electronic modules of a field device must be electrically contacted with one another, and on the other hand, the field device as a whole must be able to be contacted externally in order to be able to communicate accordingly. Internal communication between each other takes place primarily on the basis of

• - UART (Universal Asynchronous Receiver Transmitter"),
• - SPI (“Serial Peripheral Interface”), or des
• - CDI (“Common Data Interface”)

protocol. Externally, for example, using

• - USB (“Universal Serial Bus”),
• - “Bluetooth”
• - LAN (“Local Area Network”)
• - “PROFIBUS” or
• - “(Wireless) HARD”

communicated. The individual modules are usually also supplied with power via the corresponding data lines.

External communication and, if necessary, the central line supply takes place via a common interface module. In this context, on the one hand for reasons of space and on the other hand to comply with explosion protection requirements - in particular in accordance with the EN 60079 series of standards - not every electronic module of the field device is assigned its own external interface module.

The respective electronic modules can be connected to the common, external interface module either serially or in parallel - for example according to the CAN architecture (“Controller Area Network”). The advantage of a parallel connection architecture is that you can communicate directly or quickly with each individual module via the interface module. However, only a few types of FPGAs or microcontrollers are CAN-capable as potential electronic modules. In addition, communication via CAN-based data packets requires comparatively high performance, which makes compliance with explosion protection regulations more difficult.

In the case of serial communication between the electronic modules or to/from the interface module, it is easier to comply with any explosion protection requirements due to lower power consumption. However, the data transfer rate is greatly reduced in the case of serial connection between the modules, since the corresponding data packet has to be decoded in each module regardless of the protocol used, even if the data packet is not addressed to this module but has to be forwarded.

The invention is therefore based on the object of providing a modular field device in which all modules can communicate with each other at a high data transmission rate, while explosion protection specifications can be met.

• - Ein Schnittstellen-Modul, über das Datenpakete nach extern gesendet und/oder von dort empfangen werden können. Das Datenpaket bzw. der zugrundeliegende Frame ist hierbei gemäß eines solchen Protokolls auszulegen, so dass das jeweilige Datenpaket neben den eigentlichen Daten zwecks Adressierung eine definierte Kanal-Identifikation beinhaltet.
• - Ein erstes Elektronik-Modul, das ausgelegt ist, zumindest die jeweilige Kanal-Identifikation eingehender Datenpakete auszulesen, mit
  • ◯ einer ersten internen Schnittstelle, und
  • ◯ einer zweiten internen Schnittstelle,
• - eine erste physikalische Datenleitung, welche das Schnittstellen-Modul mit der ersten internen Schnittstelle verbindet, so dass gemäß des Protokolls Datenpakete bidirektional zwischen dem Schnittstellen-Modul und dem ersten Elektronik-Modul übertragbar sind.
• - Ein zweites Elektronik-Modul, mit
  • ◯ zumindest einer dritten internen Schnittstelle, und
• - eine zweite physikalische Datenleitung, welche die zweite interne Schnittstelle mit der dritten internen Schnittstelle verbindet, so dass protokollgemäß Datenpakete bidirektional zwischen erstem und zweitem Elektronik-Modul übertragbar sind.

The invention solves this problem through a modular field device that includes at least the following components:

• - An interface module through which data packets can be sent externally and/or received from there. The data packet or the underlying frame is here to be designed according to such a protocol, so that the respective data packet contains a defined channel identification in addition to the actual data for addressing purposes.
• - A first electronic module that is designed to read out at least the respective channel identification of incoming data packets
  • ◯ a first internal interface, and
  • ◯ a second internal interface,
• - a first physical data line which connects the interface module to the first internal interface, so that data packets can be transmitted bidirectionally between the interface module and the first electronics module according to the protocol.
• - A second electronic module, with
  • ◯ at least a third internal interface, and
• - a second physical data line, which connects the second internal interface with the third internal interface, so that data packets can be transferred bidirectionally between the first and second electronic module according to the protocol.

Within the scope of the invention, the at least three modules of the field device are connected to one another serially via a physical data line. This makes it possible to implement the field device in an explosion protection-compliant manner using simple measures, for example by arranging a power limiting device in the first data line. As a possible exemplary embodiment of a power limiting device, reference is made to the patent EP 03488197 B1 referred.

According to the invention, each of the modules of the field device shares a common channel identification with every other module. This defines a “virtual channel” between each of the modules of the field device. The first electronic module forwards all data packets that arrive via the first internal interface or the second internal interface, in particular without decoding, to the other internal interface of the first electronic module, provided that the first electronic module has the corresponding channel identification incoming data packet is not shared with any of the other modules. According to this principle of “virtual channels”, data packets that are not addressed to the corresponding module are, according to the invention, forwarded serially without the data packet having to be completely decoded or processed in this module. This significantly increases the possible data transfer rate within the field device without the modules having to be physically connected in parallel. In this context, it is advantageous if at least the first electronic module includes an interface driver that is able to determine the corresponding channel identification of the incoming data packet. This determines the channel identification at a low software level. This enables efficient forwarding of the data packet with low latency and/or low computing power. At this software level, any conflict management can also be implemented during simultaneous transmission on one of the data lines by the interface driver prioritizing or buffering incoming data packets, for example according to the mutex principle or according to the semaphore principle.

However, if the same baud rate is not set per se in the two internal interfaces of the first electronic module, the data packet to be forwarded must be at least temporarily stored in the first electronic module. Accordingly, it is advantageous within the scope of the invention if at least the first internal interface and the second internal interface, in particular the interfaces of all modules of the field device, have the same baud rate.

According to the principle according to the invention, the modules of the field device each store or process all those data packets that arrive via one of the interfaces of this module, provided that the respective module shares the channel identification of the corresponding data packet with one of the other modules. In this case, the data packet is not forwarded by the module via one of the module interfaces, unless several or all modules of the field device share the underlying channel identification as a common channel identification. In this case, the first electronic module processes all those incoming data packets that contain the corresponding, common channel identification, with these data packets also being forwarded to the other interface. This makes it possible to distribute data packets to all modules of the field device if necessary.

In order to be able to check whether a data packet was received correctly by the addressed module, the modules can optionally be designed so that they send out a response data packet with identical channel identification via the interface via which the data packet to be processed is received . The response data packet contains at least one confirmation of receipt as data or information. Within the scope of the invention, it is also conceivable to design the field device in such a way that data packets depending on their Channel identification can be sent using different protocols.

• 1: Ein schematischer Aufbau einer ersten Ausführungsvariante des erfindungsgemäßen Feldgerätes, und
• 2: eine zweite Ausführungsvariante des erfindungsgemäßen Feldgerätes.

The invention is explained in more detail using the following figures. It shows:

• 1 : A schematic structure of a first embodiment variant of the field device according to the invention, and
• 2 : a second embodiment variant of the field device according to the invention.

To understand the invention is in 1 the schematic structure of a field device 1 is shown, which is connected via an interface module 10, such as “Ethernet”, “PROFIBUS”, “HART” or “Wireless HART” to a higher-level unit 2, for example a process control system or a decentralized server. The field device 1 can use this to transmit the current measured value so that the process control system can, if necessary, control corresponding actuators of the process system, such as cooling elements, pumps, inflows or outflows. Information about the operating status of the level measuring device 1 can also be communicated to the higher-level unit 2. In this context, a higher-level unit 2 can also be understood as a handheld device such as a mobile radio device, by means of which the field device 1 can optionally be parameterized.

In addition to the interface module 10, the field device 1 includes two further electronic modules 11, 13, which can be based, for example, on an FPGA or a microcontroller. For example, the sensor-specific measuring principle is implemented in the second electronic module 13 in order to record the corresponding process variable or the corresponding measured value. The process variable can be, for example, a fill level in a container of the process plant, so that a radar-based transit time method, such as pulse transit time or FMCW (“Frequency Modulated Continuous Wave”), is implemented as a measuring principle in the second electronic module 13. The first electronic module 11 can, for example, serve as a data display, for example for the measured value or a possible battery charge level, and thus include a display and the underlying control. Due to the modular design of the field device 1, it is possible, for example, to use the first electronic module 11 as a data display in other types of field devices.

As in 1 is shown, the modules 10, 11, 13 of the field device 1 are connected to one another in series according to the invention. That is, a first, physical data line 12 connects the interface module 10 to a first internal interface 111 of the first electronics module 11. The second electronics module 13 is in turn connected to the first electronics module 11 via a second data line 14. For this purpose, the first electronics module 11 includes a corresponding, second internal interface 112. Correspondingly, the second electronics module 13 includes a third internal interface 131, which is connected to the second internal interface 112 of the first electronics module 11 via the second data line 14 is.

The power supply to the two electronic modules 11, 13 can take place via the interface module 10. In this case, the serial connection of the modules 10, 11, 13 makes it possible to design the field device 1 in accordance with explosion protection using simple measures: As in 1 is shown, this can be achieved by arranging a power limiting device 15 between the interface module 10 and the first electronics module 11. By connecting the modules 10, 11, 13 in series, both the first electronics module 11 and the second electronics module 13 are limited in terms of power by means of the power limiting device 15, without each of these two modules 11, 13 having its own power limiting device. Setup 15 requires. The power limiting device 15 can be implemented, for example, on the basis of a clocked switch, such as in the patent EP 03488197 B1 is described.

• - CH1: Zwischen dem Schnittstellen-Modul 10 bzw. der übergeordneten Einheit 2 und dem ersten Elektronik-Modul 11,
• - CH2: Zwischen dem ersten Elektronik-Modul 11 und dem zweiten Elektronik-Modul 13,
• - CH3: Zwischen dem zweiten Elektronik-Modul 13 und dem Schnittstellen-Modul 10.

According to the invention, the communication between the modules 10, 11, 13 as well as the external communication from or to the higher-level unit 2 takes place by defining one channel CH1, CH2, CH3 between each of the three modules 10, 11, 13. That is, at the in 1 The following channels are defined in the exemplary embodiment shown:

• - CH1: Between the interface module 10 or the higher-level unit 2 and the first electronics module 11,
• - CH2: Between the first electronics module 11 and the second electronics module 13,
• - CH3: Between the second electronics module 13 and the interface module 10.

In addition to these channels CH1, CH2, CH3 is in 1 shown embodiment is defined as a further channel CH4, which serves as a general address for all modules 10, 11, 13.

By defining such channels CH1-CH4, data packets [ID _CHx ; data], which are to be sent via the data lines 12, 14 between the modules 10, 11, 13, are addressed to the desired module 10, 11, 13: According to the definition of the channels CH1-4, the data packets [ID _CHx ; data] to be logged in such a way that their frame contains an ent speaking selectable channel identification ID _CHx includes.

Accordingly, a targeted transmission process proceeds as follows: The sending module 10, 11, 13 gives ID _CHx as the channel identification in the frame of the data packet to be sent [ID _CHx ; data] indicates the channel identification ID _CHx of the channel CH1-4 that it shares with the desired target module 10, 11, 13. If, for example, a data packet [ID _CHx ; data] is to be sent to the first electronic module 11, channel CH1 is the channel identification ID _CH1 of the corresponding data packet [ID _CH1 ; data]. As soon as this data packet [ID _CH1 ; data] is received by the first internal interface 111 of the first electronics module 11, the first electronics module 11 or the first internal interface 111 checks whether the channel CH1, which is in the frame of the data packet [ID _CH1 ; data] is specified as channel identification ID _CH1 , is shared by the first electronic module 11. If this is the case, the first electronic module 11 can receive the entire data packet [ID _CH1 ; data] depending on the protocol used, to decode the actual data of the data packet [ID _CH1 ; data] to store or process. In the case of the first electronic module 11, the data can be, for example, a text to be displayed, provided that this module 11 is a display module. Depending on the design, the first electronic module 11 can send a self-addressed data packet [ID _CH1 ; data] receives a response data packet [ID _CH1 ; data], which as channel identification ID _CHx , the same channel CH1-3, as in the received data packet [ID _CHx ; data]. This ensures that the response data packet [ID _CHx ; data] is addressed back to the sending module 10, 11, 13. The data record of the response data packet [ID _CHx ; data] contains the information that it was received completely from the first electronic module 11.

The opposite case occurs if the check by the first electronic module 11 shows that the channel CH3 that is in the frame of the incoming data packet [ID _CH3 ; data] is specified as channel identification ID _CH3 , is not shared by the first electronics module 11: In this case, the first electronics module 11 transfers the data packet [ID _CH3 ; data] for forwarding, according to the invention, to the other internal interface 111, 112, via which the received data packet [ID _CH3 ; data] was not received without the first electronic module 11 receiving the data packet [ID _CH3 ; data] has to be completely decoded. If all interfaces 111, 112 of the first electronic module 11 are operated with the same baud rate, the data packet [ID _CH3 ; data] in this case cannot be temporarily stored in the first electronic module 11.

According to this inventive design of the first electronic module 11, in the case of the exemplary embodiment of 1 all those data packets [ID _CH3 ; data], in which CH3 is specified as channel identification ID _CH3 , is forwarded from the first interface 111 of the first electronic module 11 to its second interface 112, or vice versa. This makes it possible according to the invention for the interface module 10 and the second electronic unit 13 to also receive data packets [ID _CH3 ; data can be exchanged virtually directly with each other] without this data packet [ID _CH3 ; data] must be decoded or processed for this in the first electronic unit 11. The only exception in this context is CH4: Since the corresponding channel identification ID _CH4 is used to identify a corresponding data packet [ID _CHx ; data] or its data to be sent to all modules 10, 11, 13, a correspondingly addressed data packet [ID _CH4 ; data] is decoded by the first electronic unit 11 and also forwarded to the internal interface 111, 112 from which the data packet [ID _CH4 ; data] not received [ID _CH4 ; data].

Overall, the inventive form of case-dependent forwarding of data packets [ID _CHx data] enables a potentially high data transfer rate between all modules 10, 11, 13 despite the serial connection of the modules 10, 11, 13. The data transfer rate can be further increased in that the channel identification ID _CHx is read out at a low software level of the interfaces 10, 111, 112, 113, 131, 161, for example by means of the interface driver, in order to minimize the effort required for decoding.

The data transmission according to the invention already works if the first or forwarding electronic module 11 in the case of a data packet to be forwarded [ID _CHx ; data] can only read out its channel identification ID _CHx . Only the module 10, 11, 13 to which the data packet [ID _CHx data] is addressed must be able to completely decode it according to the protocol. It follows from this that communication can be carried out using different protocols on different channels CH1-4, at least under these conditions, i.e. as long as the channel identification ID _CHx is available.

Building on the in 1 In the embodiment variant of the field device 1 shown, the case-dependent data forwarding according to the invention can generally be extended to any electronic module of the field device 1, which has two modules serially connected to each other via appropriate data lines or internal interfaces. For example, in the case (not shown) that a third electronics module 16 is additionally connected serially to the second electronics module 13, the case-dependent forwarding of the data packet [ID _CHx data] from the third internal interface 131 to that internal interface of the second electronics module 13, which is connected to the third electronics module 16 - or vice versa - to also be implemented in the second electronics module 13 in the sense of the invention.

• - CH4 wird mit allen anderen Modulen 10, 11, 13 geteilt,
• - CH5 wird mit dem zweiten Elektronik-Modul 13 geteilt,
• - CH6 wird mit dem Schnittstellen-Modul 10 geteilt,
• - CH7 wird mit dem ersten Elektronik-Modul 11 geteilt.

2 shows compared to 1 an extended embodiment variant of the field device 1 according to the invention, in which the third electronics module 16 is connected to a fourth internal interface 113 of the first electronics module 11 via a third data line 17. Additional channels CH4-CH7 are defined accordingly, which the third electronics module 16 shares:

• - CH4 is shared with all other modules 10, 11, 13,
• - CH5 is shared with the second electronic module 13,
• - CH6 is shared with the interface module 10,
• - CH7 is shared with the first electronics module 11.

For reasons of clarity, in 2 the channels CH1-4 are not shown, although they are also defined in this embodiment variant.

Corresponding to the in 1 The embodiment variant shown is also available 2 the first electronic module 11 is designed to receive data packets [ID _CHx ; data] that arrives via one of its internal interfaces 111, 112, 113, provided that the first electronic module 11 has the corresponding channel identification ID _CH3 of the incoming data packet [ID _CHx ; data] does not share with any of the other modules 10, 13, 16. However, in this case there are two possible options for implementing redirection. Either, the data packet [ID _CHx ; data] is virtually blindly forwarded to all other internal interfaces 111, 112, 113, with the exception of those of the internal interfaces 111, 112, 113, via which the data packet [ID _CHx ; data] is received. Or the first electronic module 11 routes the incoming data packet [ID _CHx ; data] is only forwarded specifically to the internal interface 111, 112 which contains the module 10, 13, 16 to which the data packet [ID _CHx ; data] is addressed. This optional design assumes that an assignment is stored in the first electronics module 11, based on which the first electronics module 11 selects the specific internal interface 111, 112, 113 for forwarding. It is assigned to which internal interface 111, 112, 113 an incoming data packet [ID _CHx ; data] is to be forwarded, depending on the channel CH1-7 specified there, as well as depending on the internal interface 111, 112, 113 via which the data packet [ID _CHx ; data] is received. 2 This makes it clear that the idea of case-dependent forwarding according to the invention can be transferred to any computer architecture of field devices.

Reference symbol list

1

Field device

2

Parent/external entity

10

Interface module

11

First electronic module

12

First data line

13

Second electronic module

14

Second data line

15

Power limitation device

16

Third electronic module

111

First internal interface

112

Second internal interface

113

Fourth internal interface

131

Third internal interface

CH1-CH7

channels

IDCHx

Channel identification

[IDCHx; data]

Data package

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 03488197 B1 [0010, 0019]

Claims (11)

Field device, comprising: - An interface module (10), via which data packets ([ID _CHx ; data]) logged in this way can be sent and/or received, so that the respective data packet ([ID _CHx ; data]) has a defined one for addressing Channel identification (ID _CHx ) includes - a first electronic module (11), which is designed to read out at least the respective channel identification (ID _CHx ) of incoming data packets ([ID _CHx ; data]), with o a first internal Interface (111), and o a second internal interface (112), - a first data line (12), which connects the interface module (10) for the bidirectional transmission of the data packets ([ID _CHX ; data]) to the first internal interface ( 111) of the first electronics module (11) connects, - a second electronics module (13), with a third internal interface (131), and - a second data line (14), which has the second internal interface (112). the third internal interface (131) connects so that data packets ([ID _CHx ; data]) can be transmitted bidirectionally, each of the modules (10, 11, 13) sharing a common channel identification (ID _CHx ) with every other module (10, 11, 13), and the first electronic module ( 11) is designed to forward a data packet ([ID _CHx ; data]), which arrives via the first internal interface (111) or the second internal interface (112), to the other internal interface (111, 112), if this is the case first electronic module (11) does not share the corresponding channel identification (ID _CHx ) of the incoming data packet ([ID _CHx ; data]) with one of the other modules (10, 13). field device Claim 1 , wherein the first electronic module (11) is designed to transmit the data packet ([ID _CHx ; data]) without decoding from the first internal interface (111) to the second internal interface (112) or vice versa. field device Claim 1 or 2 , wherein the modules (10, 11, 13) are designed to process a data packet ([ID _CH1 ; data]) that arrives via one of their interfaces (10, 111, 112, 131), provided that the corresponding module (10 , 11, 13) shares the channel identification (ID _CHx ) of this data packet ([ID _CHx ; data]) with at least one of the other modules (10, 11, 13). field device Claim 3 , whereby the modules (10, 11, 13) are designed to receive a response data packet ([ _{ID CH1} ; data]) with identical channel identification (ID _CHx ). Field device according to at least one of the preceding claims, wherein at least the first internal interface (111) and the second internal interface (112), in particular all interfaces (111, 112, ) of the field device (1), have the same baud rate. Field device according to at least one of the preceding claims, wherein a power limiting device (15) is arranged in the first data line (12). Field device according to at least one of the preceding claims, wherein the data packet ([ID _CHx ; data]) is logged according to one of the standards UART, SPI, CDI, USB, Bluetooth, LAN, PROFIBUS, HART or Wireless HART. Field device according to at least one of the preceding claims, which is designed to send data packets ([ID _CHx ; data]) according to different protocols depending on their channel identification (ID _CHx ). Field device according to at least one of the preceding claims, wherein the modules (10, 11, 13) each comprise such an interface driver, so that the corresponding channel identification (ID _CHx ) of the incoming data packet ([ID _CHx ; data]) is determined by means of of the interface driver is determined. field device Claim 9 , wherein the interface driver is designed to prioritize or buffer incoming data packets ([ID _CHx ; data]), in particular according to the mutex principle or according to the semaphore principle. Field device according to at least one of the preceding claims, wherein all modules (10, 11, 13) share a common channel identification (ID _CH4 ), and wherein the first electronic module (11) is designed to receive data packets ([ID _CH1 ; data]), which contain the corresponding channel identification (ID _CH4 ), and forward it to the other interface (111, 112), provided that this data packet ([ID _CH1 ; data]) via one of its interfaces (111, 112 ) is received.

Images