Method for intercontroller communications in A safety instrumented system or a process control system

• US 20070083275A1
• Filed: 09/29/2006
• Published: 04/12/2007
• Est. Priority Date: 01/28/2003
• Status: Active Grant

• Current Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Original Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Inventors: Law, Gary, Burr, Kent, Sherriff, Godfrey
• Granted Patent: US 7,865,251 B2
• Time in Patent Office: Days
• US Class Current: 700/19
• CPC Class Codes: G05B 19/41855 by local area network [LAN], network structure
• CPC Class Codes: G05B 2219/31348 Gateway
• CPC Class Codes: G05B 23/027 Alarm generation, e.g. communication protocol; Forms of alarm
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

The claimed system provides an I/O card that is used to interface two process controllers over a communication line that is separate from a primary communication line connecting the two process controllers to a workstation. The process controllers can access the I/O cards in a similar manner to I/O cards used to connect to field devices. In this manner, the physical hardware and software architecture does not need to be modified for inter-controller communications. Inter-controller communications can be programmed as general I/O communication.

Claims

1. An input/output (I/O) bus connection system for use in a process control system comprising:

a first I/O card including a processor, a memory, and two interfaces, wherein a first interface of the first I/O card is communicatively coupled to a first process controller via a first bus;

a second I/O card including a processor, a memory, and two interfaces, wherein a first interface of the second I/O card is communicatively coupled to a second process controller via a second bus; and

an inter-controller communication link between the first I/O card and the second I/O card separate from the first and the second bus, wherein the second interface of the first I/O card and the second interface of the second I/O card are communicatively coupled to the inter-controller communication link.

2. The system of claim 1, wherein the inter-controller communication link comprises one of an intranet or the Internet.

3. The process control system of claim 1, wherein the inter-controller communication link comprises a communication network running one of an Ethernet, Token Ring, FDDI, ARCNET, WiFi, serial or parallel communication protocol.

4. The system of claim 1, wherein the first bus comprises a plurality of input/output (I/O) cards, separate from the first I/O card, that is operatively connected to the first process controller via the first bus, wherein the plurality of I/O cards includes at least one I/O card adapted for operative communication with a process control related field device or a safety related field device.

5. The system of claim 4, wherein the second bus comprises a plurality of input/output (I/O) cards, separate from the second I/O card, that is operatively connected to the second process controller via the second bus, wherein the plurality of I/O cards includes at least one I/O card adapted for operative communication with a process control related field device or a safety related field device.

6. The system of claim 4, wherein the first process controller implements a control routine to produce a device control signal based on one or more process parameter measurement signals and wherein a first interface of the at least one I/O card is adapted to receive one or more device control signals from the first process controller for the first device via the first bus or to provide one or more process parameter measurements from the first device to the process controller.

7. The system of claim 1, further comprising a third I/O card including a processor, a memory, and two interfaces, wherein a first interface of the third I/O card is communicatively coupled to a third process controller via a third bus and wherein a second interface of the third I/O card is communicatively coupled to the inter-controller communication link.

8. The system of claim 1, further comprising a third I/O card including a processor, a memory, and two interfaces, wherein a first interface of the third I/O card is communicatively coupled to a third process controller via a third bus and wherein a second interface of the third I/O card is communicatively coupled to the first process controller via the first bus.

9. The system of claim 1, further comprising a first communication network separate from the first bus, the second bus, and the inter-controller communication link, and wherein the first process controller and the second process controller are communicatively coupled to the first communication network and adapted to communicate with a host computer arranged to send and receive process control messages and safety messages.

10. A method of communicating between two process controllers within a process control system comprising:

transmitting a first controller signal from a first process controller to a first I/O device via a first bus, wherein the first bus is communicatively coupled to the first process controller and the first I/O device;

connecting a second I/O device to the first I/O device over a first communication network separate and independent from the first bus and transmitting the first controller signal from the first I/O device to a second I/O device via the first communication network;

transmitting the first controller signal from the second I/O device to a second process controller via a second bus separate and independent from the first bus and the first communication network, wherein the second bus is communicatively coupled to the second process controller and the second I/O device.

11. The method of claim 10, further comprising determining by the first process controller whether one of a process parameter measurement signal, an alarm, or an event needs to be communicated to a second process controller.

12. The method of claim 10, further comprising determining whether the first I/O device is connected to the first bus and foregoing transmitting the first controller signal to an operator workstation.

13. The method of claim 10, further comprising determining at the second process controller whether a field device under the control of the second process controller is to be adjusted based on the first controller signal, and transmitting a device control signal from the process controller to the field device if it is determined that the field device is to be adjusted.

14. The method of claim 10, further comprising relaying the control signal by the second processor to a field device connected to an I/O device on the communication second bus.

15. The method of claim 10, further comprising a second communication network, separate and independent from the first bus, the second bus, and the first communication network, wherein the communication network is communicatively coupled directly to the first process controller and directly to the second process controller and further coupled to a host computer.

16. The method of claim 10, wherein the first bus and second bus use a first communication protocol, and the first communication network and the second communication network use a second communication protocol.

17. The method of claim 10, further comprising translating the first controller signal from a first protocol used by the first bus to a second protocol used by the first communication network.

18. The method of claim 17, further comprising translating the first controller signal from the second protocol used by the first communication network to a third protocol used by the second bus.

19. The method of claim 18, wherein the first and third communication protocols are the same.

20. The method of claim 10, wherein the first controller signal comprises one of a device control signal, a process parameter measurement signal, an event signal, or an alarm signal.

21. A process control system comprising:

a host computer arranged to send and receive process control messages;

a first controller operatively connected to the host computer via a first communication network and adapted to perform process control functionality;

a first I/O card operatively connected to the first controller via a first bus and adapted for operative communication with a process control related field device;

a second I/O card operatively connected to the first controller via the first bus and adapted for operative communication with a third I/O card, the second I/O card and third I/O card operatively connected via a second communication network separate from the first bus and the first communication network.

22. The process control system of claim 21, further comprising a fourth I/O card adapted for operative communication with the second I/O card and third I/O card via the second communication network and for operative communication with a second controller via a third bus.

23. The process control system of claim 21, further comprising a fourth I/O card operatively connected to the first controller via the first bus and adapted for operative communication with a fifth I/O card via a third communication network separate and independent from the first and second communication network and the first bus.

24. The process control system of claim 21, wherein the process controller implements a control routine to produce a device control signal based on one or more process parameter measurement signals, and wherein a first interface of the first I/O card is adapted to receive one or more device control signals from the process controller for the process control related field device via the first bus or to provide one or more process parameter measurements from the process control related field device to the first process controller.

25. The process control system of claim 21, wherein the first I/O card is adapted for operative communication with the process control related field device using one of HART, 4-20 ma protocol, Foundation Fieldbus protocol, CAN, Profibus, or AS-Interface protocol.

26. The process control system of claim 21, wherein the third I/O card is adapted for operative communication with a second controller via a second bus.

27. The process control system of claim 26, wherein the first bus and the second bus operate using the same communication protocol.

28. The process control system of claim 27, wherein the first communication network and the second communication network operate using the same communication protocol.

29. The process control system of claim 28, wherein the second communication network comprises a communication network running one of an Ethernet, Token Ring, FDDI, ARCNET, WiFi, serial or parallel communication protocol.

30. The process control system of claim 29, wherein the second communication network comprises a communication bus between the second I/O card and third I/O card.

31. The process control system of claim 21, wherein the third I/O card is adapted for operative communication with a second controller.

32. The process control system of claim 31, further comprising a fourth I/O card connected to the first controller via the first bus and adapted for operative communication with a first safety-related field device, the fourth I/O card including a processor that executes a safety module for implementing the safety functionality using the safety-related field device.

33. The process control system of claim 32, further comprising a first message propagation device connected to the first bus, a second message propagation device connected to the second bus, and a fifth I/O device connected to the second bus, wherein the fifth I/O card is adapted for operative communication with a second safety-related field device, the fifth I/O card including a processor that executes a safety module for implementing safety functionality using the safety-related field device.