Junction box unit for input / output devices of a modular process control system

Abstract

A terminal block unit (100) for an input / output device (200) of a modular process control system comprises two slot elements (110, 120) configured to receive two redundant signal conditioning units (400, 410); wherein the terminal block unit (100) is configured to be housed in a pair of two adjacent slot elements of a module termination unit (300) of the input / output device (200); wherein the terminal block unit (100) provides a parallel connection of the redundant signal conditioning units (400, 410) to a field device.

Description

TECHNICAL FIELD

[0001] The present invention relates to a terminal block unit for an input / output device of a modular process control system, to an input / output device having such a terminal block unit, and to a modular process control system having such an input / output device. BACKGROUND

[0002] Process control systems are generally known in the prior art. Process control systems comprise several different hardware units, e.g. at least one I / O module with several signal conditioning units, a power supply, a communication interface unit and a control unit. Process control systems are used, inter alia, for controlling complex production plants, e.g. in the process industry or the automotive industry. For example, the applicant has developed such a system under the model designation ABB Ability System 800xA Select I / O.

[0003] It is now apparent that there is a need to provide I / O channels of I / O modules redundantly in a simple and secure manner. SUMMARY

[0004] In view of the above, it is an object of the present invention to provide a possibility to provide I / O channels of I / O modules redundantly in a simple and secure manner. These and other objects, which will become clear by reading the following description, are solved by the subject matter of the independent claims. The dependent claims relate to preferred embodiments of the invention.

[0005] According to one aspect of the present disclosure, a terminal block unit for an input / output device of a modular process control system is provided, the terminal block unit comprising:

[0006] two slot elements configured to receive two redundant signal conditioning units;

[0007] wherein the terminal block unit is configured to be accommodated in a pair of two adjacent slot elements of a module termination unit of the input / output device;

[0008] wherein the terminal block unit provides a parallel connection of the redundant signal conditioning units to a field device.

[0009] It is noted that the terminal block unit is preferably configured to be accommodated directly in the pair of two adjacent slot elements of the module termination unit, i.e. without arranging further contact elements, units, modules, etc. between the slot elements of the module termination unit and the plugs / jacks / connectors of the terminal block unit.

[0010] In one embodiment of the terminal block unit, the parallel connection is provided by means of hardwiring and / or by means of an electronic redundancy circuit comprising electronic elements, e.g. elements for voltage, power limitation and common current shunting, or such as fuses.

[0011] In one embodiment of the terminal block unit, the terminal block unit does not provide a direct communication channel between the two redundant signal conditioning units.

[0012] In one embodiment of the terminal block unit, the terminal block unit comprises a redundant contact element configured to provide a communication link between the redundant signal conditioning units. The general purpose input / output unit handles the communication between the field bus communication interface and the signal conditioning units. The general purpose input / output unit communicates upstream with the field bus communication interface, e.g. Modulebus, and downstream with up to various signal conditioning units, e.g. up to 16 signal conditioning units. Such a general purpose input / output unit can be used in single or redundant mode.

[0013] In one embodiment of the terminal block unit, the terminal block unit comprises only two slot elements configured to receive only two redundant signal conditioning units.

[0014] In one embodiment of the terminal block unit, the terminal block unit comprises at least one blocking element configured to prohibit the insertion of certain (e.g. not supported signal series types) signal conditioning units into the slot elements, e.g. intrinsically safe signal conditioning units, 24V signal conditioning units, high voltage signal conditioning units and / or any other signal type series, wherein the blocking element is preferably arranged at the slot element.

[0015] In one embodiment of the terminal block unit, the terminal block unit comprises a coding element configured to cooperate with a coding element of the signal conditioning unit to determine the type of the signal conditioning unit.

[0016] In one embodiment of the terminal block unit, the terminal block unit comprises an identification element configured to provide information to the signal conditioning unit that the terminal block unit is a redundant terminal block unit for receiving two redundant signal conditioning units.

[0017] In one embodiment of the terminal block unit, the terminal block unit comprises at least one probe hole for measurement purposes, e.g. for measuring voltage, signals and / or for a communication link with a hand-held device for diagnostics, settings, uploading measurements.

[0018] According to another aspect, an input / output device is provided, comprising at least one module termination unit accommodating at least one general purpose input / output unit and at least one terminal block unit as described above.

[0019] In one embodiment of the input / output device, the module termination unit comprises 8 to 32 slot elements, preferably 18 slot elements, which accommodate two universal input / output units and provide 16 additional slot elements for single termination blocks (each occupying one slot element) and / or (redundant) termination blocks (each occupying two slot elements of the module termination block) as described above.

[0020] According to another aspect, a modular process control system is provided, comprising at least one input / output device, wherein at least one terminal block unit as described above is accommodated in a module termination unit of the input / output device, and wherein in a slot element of the terminal block unit, a pair of redundant signal conditioning units is accommodated.

[0021] In one embodiment of the modular process control system, the two redundant signal conditioning units are configured to read or write process values of the field device in parallel.

[0022] In one embodiment of the modular process control system, the signal conditioning units are configured to provide an analog output, wherein the two signal conditioning units share the current and drive the total process value of the field device, wherein the two signal conditioning units preferably share the current and drive 50% of the total process value of the field device.

[0023] In one embodiment of the modular process control system, the signal conditioning units are configured to provide a digital output, wherein only the primary signal conditioning unit is active and the standby signal conditioning unit continuously listens for communication. BRIEF DESCRIPTION OF DRAWINGS

[0024] In the following, the present disclosure will be exemplarily described with reference to the accompanying drawings, in which:

[0025] Figure 1 A schematic diagram of a terminal block unit according to an embodiment of the present disclosure is shown;

[0026] Figure 2 A schematic cross-sectional view of an input / output device according to an embodiment of the present disclosure is shown;

[0027] Figure 3 A schematic exemplary wiring diagram of a redundant signal conditioning unit in an input / output device is shown;

[0028] Figure 4 Schematic top views of an input / output device with a redundant terminal block unit and a single terminal block unit are shown; and

[0029] Figure 5 A schematic diagram of a redundant contact element is shown. DETAILED DESCRIPTION

[0030] In Figure 1 , a terminal block unit 100 for an input / output device of a modular process control system is schematically shown. The terminal block unit 100 comprises two input / output slot elements 110 and 120 configured to receive two redundant signal conditioning units (see Figure 2 ). The redundant signal conditioning units are preferably identical or at least provide the same technical functionality. The terminal block unit 100 can comprise for each terminal a probe hole 130, 140 for connecting a test probe for voltage measurement. By means of a contact connection, e.g. a U-shaped contact element, the terminal block unit 100 can be accommodated in a pair of two adjacent slot elements of a module termination unit 300 (see Figure 2 ). Furthermore, the terminal block unit 100 can comprise several input clamps or screw contacts 160, 170 for input, e.g. power supply voltage, ground connection, etc. Finally, the terminal block unit 100 can comprise a socket 150 for inserting the terminal block unit into the module termination unit 300.

[0031] Figure 2 A schematic cross-sectional view of an input / output device 200 is shown, which comprises a module termination unit 300, at least one terminal block unit 100 as shown in Figure 1 accommodated in the module termination unit 300, and at least two redundant signal conditioning units 400, 410 accommodated in the terminal block unit 100. As shown in Figure 2 , the terminal block unit 100 can further comprise a field connection 180.

[0032] Figure 3 A schematic exemplary wiring diagram of the redundant signal conditioning units 400, 410 in the terminal block unit 100 accommodated in the input / output device 200 is shown. As shown, the inputs of the primary signal conditioning unit 400 and the inputs of the backup signal conditioning unit 410 are connected in parallel to a process input signal 500 of a field device (not shown). Furthermore, the outputs of the primary signal conditioning unit 400 and the outputs of the backup signal conditioning unit 410 are also connected in parallel to at least one general purpose input / output unit, wherein in the preferred embodiment shown, redundant general purpose input / output units 420, 430 are provided. In the preferred embodiment, the general purpose input / output units 420, 430 are connected via a communication link 440.

[0033] Figure 4A schematic top view of an input / output device 200 with redundant terminal block units 100 and single terminal block units 600 is shown, wherein the slot elements 700 of the input / output device 200 are not used. As shown, the process input signals 500 of the field devices (not shown) can be connected in parallel to a pair of redundant signal conditioning units 400 and 410. The input / output device 200 further comprises a connector element 800 to the system interface. Also as shown, the terminal block units 100 can further comprise redundant contact elements 190 configured to provide a communication link between the redundant signal conditioning units 400 and 410. Figure 4 and Figure 5 As shown, the terminal block units 100 can further comprise redundant contact elements 190 configured to provide a communication link between the redundant signal conditioning units 400 and 410.

[0034] Figure 5 The redundant contact elements 190 and their contacts to the redundant signal conditioning units 400 and 410 are shown in more detail. The PCB 401 of the primary signal conditioning unit 400 and its contact pads 402 and 403 are shown on the left side, while the PCB 411 of the backup signal conditioning unit 410 and its contact pads 412 and 413 are shown on the right side. By means of the redundant contact elements 190, a short circuit of the contact pads 402 to 403 or 412 to 413 allows for a detection to the redundant terminal block of the signal conditioning unit. Furthermore, the contact can also be used to provide a communication link for the redundant signal conditioning unit. Thus, by means of this dual functionality, the number of necessary contact elements in the terminal block unit can be reduced. At the single terminal block units 600, no such redundant contact elements 190 are provided, such that the absence of a short circuit between the contact pads 402 and 403 can indicate a single terminal unit configuration.

[0035] The effects and advantages of the present disclosure are summarized as follows:

[0036] General aspects:

[0037] For configurations requiring high availability, the input / output channels should be configured to be redundant. By means of the present disclosure, redundancy can be configured for safety and non-safety signals on a channel granularity. The signals for field connection are not routed through the backplane / module termination units (see Figure 2 ). This brings several technical and economic benefits. Only those input / output channels that have a high requirement on availability need to be configured to be redundant. Other channels on the same substrate can remain single configured to maintain a high channel density and reduce costs. During commissioning, this provides a high degree of flexibility to decide whether redundancy is required at a later stage of the project schedule. Furthermore, over the years of execution, redundancy can be added to existing channels without much effort.

[0038] Terminal block unit:

[0039] Since there is no electrical connection between the backplane and the terminal block unit, the terminal block type (e.g. single / redundant, IS / NonIS, 24V / 120V / 230V) can be chosen according to the requirements of the connected field device. Terminal block units and signal conditioning units that are not allowed to be combined (e.g. NonIS SCM and IS FTB) can include a mechanical lock preventing their combination. In case multiple terminal block units (e.g. single / redundant) can be used, different terminal block units can include a self-learning function by which the inserted signal conditioning units can be read out. This information can then be propagated to the engineering tool to simplify commissioning. For special signal types, electronics can also be added to the terminal block unit.

[0040] Signal conditioning unit redundancy:

[0041] When two signal conditioning units are intended to perform as a redundant pair, they have to be inserted into a redundant terminal block unit, through which they are connected in parallel to the field device. There is no direct communication channel between the two redundant signal conditioning units. This reduces complexity and reduces costs. The two redundant signal conditioning units can exchange information via the general purpose input / output unit(s) (see Figure 3 ). The inputs of the redundant signal conditioning units read the process value in parallel. The outputs of the redundant signal conditioning units drive the output in parallel, where in the case of analog output signal conditioning units, both modules share the current and each drive 50% of the total process value. This architecture makes it possible for the primary and the backup redundant signal conditioning unit to always have the ability to perform all monitoring. This can prevent any hidden errors from being detected first after a redundancy switch. For analog redundant signal conditioning units capable of performing HART communication, only the primary redundant signal conditioning unit is in active state, while the backup redundant signal conditioning unit continuously listens to the communication in order to provide data immediately after a redundancy switch. If the general purpose input / output unit is also configured as redundant, the backup general purpose input / output unit cyclically checks its communication link with both redundant signal conditioning units to ensure availability after a redundancy switch. Both the primary and the backup signal conditioning unit can generate alarms and events. This architecture reduces the risk of event loss in case of a redundancy switch.

[0042] The channel can be decided to be redundant according to the channel and the signal to terminal is not routed through the module terminal unit: redundant terminal block unit for safe and non-safe single channel general purpose input / output signals. Technical advantage: it is possible to define whether a channel should be redundant in a very late step of the commissioning. The system commissioning approach is flexible and easier to change later. After several years of plant operation, you can easily add a redundant channel. No need to change the backplane, just the terminal block.

[0043] The terminal box unit type can be chosen according to the signal type at hand, e.g. a relay. Technical advantage: high voltage and terminal box units according to the present disclosure can be used for different signals.

[0044] The terminal box unit detection can be used, as the signal conditioning unit can detect whether it is installed in a redundant or non-redundant terminal box. Technical advantage: the real configuration can be read out, in order to make system engineering easier.

[0045] Implicit information exchange without a direct redundant link is available. Data exchange between the redundant modules, without a separate redundant link, but via the general purpose input / output unit(s).

[0046] Technical advantage: reduced hardware costs

[0047] The backup general purpose input / output unit can cyclically check the communication link to both redundant signal conditioning units. Technical advantage: fast redundant switchover is obtained.

[0048] The ability to power the field device can be actively tested by temporarily increasing / decreasing the voltage of the backup channel compared to the active channel.

[0049] 50 / 50% output value sharing of the output module can provide the technical advantage that the output value only drops by 50% in case of a red switchover.

[0050] The backup signal conditioning unit can listen to the HART - the communication of the master redundant signal conditioning unit provides the technical advantage that HART data is provided immediately after switchover.

[0051] Both redundant signal conditioning units can generate events so that they are not lost during redundant switchover.

[0052] The present disclosure has also been described in conjunction with preferred embodiments as examples. However, other variations can be understood and implemented by those skilled in the art from a study of the drawings, of the present disclosure and of the claims. It is worth noting that, in particular, any of the steps presented can be performed in any order, i.e. the present invention is not limited to the specific order of the steps. Furthermore, it is also not required that different steps are performed at one place or at one node of a distributed system, i.e. each step can be performed at different nodes using different devices / data processing units.

[0053] In the claims, as well as in the specification above, all transitional phrases such as "comprising," "including," "carrying," "having," "containing," "involving," "holding," "providing," and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases "consisting of and "consisting essentially of shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.

Claims

1. A terminal block unit (100) for an input / output device (200) of a modular process control system, comprising: two slot elements (110, 120) configured to receive two redundant signal conditioning units (400, 410); wherein the terminal block unit (100) is configured to be accommodated in a pair of two adjacent slot elements of a module termination unit (300) of an input / output device (200); wherein the terminal block unit (100) provides a parallel connection of the redundant signal conditioning units (400, 410) to a field device.

2. The terminal block unit (100) according to claim 1, wherein the parallel connection for the redundant signal conditioning units (400, 410) is provided by means of hardwiring and / or by means of electronic redundancy circuitry.

3. The terminal block unit (100) according to claim 1 or 2, wherein the terminal block unit (100) does not provide a direct communication channel between the two redundant signal conditioning units (400, 410).

4. The terminal block unit (100) according to claim 1 or 2, wherein the terminal block unit (100) comprises a redundant contact element (190) configured to provide a communication link between the redundant signal conditioning units (400, 410).

5. The terminal block unit (100) according to claim 1 or 2, wherein the terminal block unit (100) comprises only two slot elements (110, 120) configured to receive only the two redundant signal conditioning units (400, 410).

6. The terminal block unit (100) according to claim 1 or 2, wherein the terminal block unit (100) comprises at least one blocking element configured to prohibit the insertion of certain signal conditioning units into the slot elements (110, 120).

7. The terminal block unit (100) according to claim 6, wherein the certain signal conditioning units are unsupported signal series types.

8. The terminal block unit (100) according to claim 6, wherein the certain signal conditioning units are intrinsically safe signal conditioning units, high voltage signal conditioning units and / or 24V signal conditioning units.

9. The terminal block unit (100) according to claim 6, wherein the at least one blocking element is arranged at the slot elements (110, 120).

10. The terminal block unit (100) according to claim 1 or 2, wherein the terminal block unit (100) comprises a coding element configured to cooperate with a coding element of a signal conditioning unit (400, 410) to determine a type of the signal conditioning unit (400, 410).

11. The terminal block unit (100) according to claim 1 or 2, wherein the terminal block unit (100) comprises an identification element configured to provide the signal conditioning unit (400, 410) with information that the terminal block unit (100) is a terminal block unit (100) for receiving two redundant signal conditioning units (400, 410).

12. The terminal block unit (100) according to claim 1 or 2, wherein the terminal block unit (100) comprises at least one probe hole (130, 140) for measurement purposes and / or for providing a communication link with a hand-held device for diagnostic, setup and / or upload purposes.

13. The terminal block unit (100) according to claim 12, wherein the at least one probe hole (130, 140) is for voltage measurement, signal measurement.

14. An input / output device (200) comprising at least one module termination unit (300) housing at least one universal input / output unit (420, 430) and at least one terminal block unit (100) according to any one of claims 1-13.

15. The input / output device (200) according to claim 14, wherein the module termination unit (300) comprises 8 to 32 slot elements housing two universal input / output units (420, 430), a single and / or multiple terminal block units according to any one of claims 1 to 13.

16. The input / output device (200) according to claim 15, wherein the module termination unit (300) comprises 18 slot elements.

17. A modular process control system comprising at least one input / output device (200), wherein at least one terminal block unit (100) according to any one of claims 1 to 13 is housed in a module termination unit (300) of the input / output device (200), and wherein in the slot elements (110, 120) of the terminal block unit (100) a pair of redundant signal conditioning units (400, 410) is housed.

18. The modular process control system according to claim 17, wherein the two redundant signal conditioning units (400, 410) are configured to read process values of a field device in parallel.

19. The modular process control system according to claim 17 or 18, wherein the signal conditioning units (400, 410) are configured to provide an analog output, wherein both signal conditioning units (400, 410) share current and drive the total process value of the field device.

20. The modular process control system according to claim 19, wherein both signal conditioning units (400, 410) share current and drive 50% of the total process value of the field device.

21. The modular process control system of claim 17 or 18, wherein the signal conditioning units (400, 410) are configured to provide digital outputs, wherein only the primary signal conditioning unit (400) is active and the backup signal conditioning unit (410) continuously listens for communications.

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