Shadow function block interface for use in a process control network

• US 6,738,388 B1
• Filed: 09/10/1998
• Issued: 05/18/2004
• Est. Priority Date: 09/10/1998
• Status: Expired due to Term

• Current Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Original Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Inventors: Stevenson, Dennis L., Jundt, Larry O., Dienstbier, Steve L., Tzovla, Vasiliki, Christensen, Dan D.
• Primary Examiner(s): Hsu, Alpus H.
• Assistant Examiner(s): TRAN, THIEN D
• Application Number:
  US09/151,084
• Time in Patent Office: 2,077 Days
• Field of Search: 370/410, 370/420, 370/463, 370/330, 370/436, 370/478, 370/464, 370/465, 370/466, 370/462
• US Class Current: 370/465
• CPC Class Codes: G05B 19/4185 characterised by the network communication
• CPC Class Codes: G05B 2219/23248 Integrate function blocks from different machines; CORBA, RMI protocols
• CPC Class Codes: G05B 2219/31135 Fieldbus
• CPC Class Codes: G05B 2219/31422 Upload, download programs, parameters from, to station to, from server
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A process controller that is communicatively coupled to an external field device via a communication network uses a shadow function block disposed within a process controller to enable implementation of a control routine that uses both an internal function block disposed within the process controller and an external function block disposed within the external field device. The shadow function block includes a communication port that communicates with the external function block via the communication network to thereby receive data pertaining to the external function block, a memory that stores the received data according to a configuration protocol of the internal function block and an output that provides the stored external function block data to the internal function block according to the configuration protocol of the internal function block. The communication port of the interface function block may include an output that sends data generated by the controller or the internal function block to the external function block using the communication protocol associated with the external function block.

Claims

1. A process routine implemented by a processor, wherein the processor is communicatively coupled to an external device via a communications network, the process routine comprising:

a plurality of communicatively interconnected internal function blocks located within the processor and operating according to a first protocol, the plurality of internal function blocks implemented in a scheduled manner;

a shadow function block residing within the processor and communicatively interconnected with at least one of the plurality internal function blocks according to the first protocol; and

an external function block residing within the external device and communicatively coupled to the shadow function block, wherein the shadow function block operates during its scheduled operating time to mirror data between the external function block and the at least one of the plurality of internal function blocks.

2. The process routine of claim 1, wherein the shadow function block further includes an output that passes data pertaining to the external function block to the at least one of the plurality of internal function blocks according to the first protocol.

3. The process routine of claim 2, wherein the shadow function block further includes an input that receives data pertaining to the external function block independently of the scheduled operation of the at least one of the plurality of internal function blocks.

4. The process routine of claim 3, wherein the external function block communicates via the communication network using a second protocol that is different than the first protocol and wherein the input communicates with the external function block using the second communication protocol.

5. The process routine of claim 4, wherein the second protocol is a Fieldbus communication protocol and wherein the input communicates with the external function block using the Fieldbus communication protocol.

6. The process routine of claim 5, wherein the input uses an interface device configured to communicate with the external device using the Fieldbus communication protocol to communicate with the external function block.

7. The process routine of claim 1, wherein the shadow function block further includes an input that communicates with the external function block using synchronous communications.

8. The process routine of claim 1, wherein the shadow function block further includes an input that communicates with the external function block using synchronous and asynchronous communications.

9. The process routine of claim 1, wherein the external device communicates using a device communication protocol that supports the communication of logically linked packets of data using standardized communication calls, and wherein the shadow function block communicates with the external function block using the standardized communication calls associated with the device communication protocol.

10. The process routine of claim 9, wherein the device communication protocol is a Fieldbus communication protocol, and wherein the shadow function block communicates with the external device using view objects within the Fieldbus communication protocol.

11. The process routine of claim 1, wherein the shadow function block receives an alarm indication from the external function block and wherein a memory stores the received alarm indication.

12. The process routine of claim 1, wherein the shadow function block further includes an input that communicates with the external function block and further includes an output that sends data to the external function block using a second protocol associated with the external function block.

30. The process routine of claim 1, wherein the shadow function block is configured to automatically communicate with the external function block in a periodic manner.

13. A controller adapted to be communicatively coupled to a plurality of field devices wherein one of the field devices includes an external function block that communicates using a device communication protocol, the controller comprising:

a processor;

a memory; and

a control routine including a plurality of function blocks stored in the memory and implemented by the processor in a scheduled manner to control the plurality of field devices, the plurality of function blocks including;

a multiplicity of interconnected internal function blocks configured using a controller protocol; and

a shadow function block that communicates with at least one of the multiplicity of interconnected internal function blocks using the controller protocol and that communicates with the external function block within the one of the field devices using the device communication protocol, wherein the shadow function block mirrors data pertaining to the external function block received from the external function block to one of the multiplicity of interconnected internal function blocks, thereby allowing the external function block to operate as if implemented by the processor.

14. The controller of claim 13, wherein the shadow function block mirrors the data pertaining to the external function block independently of the operation of the multiplicity of internal function blocks.

15. The controller of claim 13, wherein the device communication protocol is a Fieldbus communication protocol and wherein the interface function block communicates with the external function block using the Fieldbus communication protocol.

16. The controller of claim 15, wherein the interface function block communicates with the external function block using view objects within the Fieldbus communication protocol.

17. The controller of claim 15, wherein the interface function block communicates with the external function block using subscriber/publisher communications within the Fieldbus communication protocol.

18. The controller of claim 13, wherein the shadow function block mirrors data pertaining to inputs and outputs of the external function block.

19. The controller of claim 13, wherein the shadow function block mirrors data pertaining to alarms generated by the external function block.

20. The controller of claim 13, wherein the shadow function block mirrors data pertaining to the mode of the external function block.

21. The controller of claim 13, wherein the shadow function block mirrors data generated by the another one of the multiplicity of internal function blocks to the external function block.

22. The controller of claim 13, wherein the shadow function block mirrors a control command to the external function block.

31. The controller of claim 13, wherein the interface function block automatically communicates with the external function block in a periodic manner.

23. A method of implementing a control routine within a process controller communicatively coupled to a field device, wherein the field device has an external function block located therein and communicates using a device communication protocol, the method comprising the steps of:

storing a plurality of interconnected internal function blocks in the controller configured according to a controller protocol for implementation in a scheduled manner as part of the control routine;

creating a shadow function block within the controller configured according to the controller protocol, wherein the shadow function block is configured to mirror data between the external function block and the plurality of interconnected internal function blocks;

creating a control routine that uses the plurality of interconnected internal function blocks and data mirrored through the shadow function block from the external function block to control the process as if the external function block was within the controller; and

storing data associated with the external function block in the interface function block during implementation of the control routine.

24. The method of claim 23, further including the step of using the shadow function block to communicate with the external function block to update the data associated with the external function block independently of the operation of the plurality of interconnected internal function blocks.

25. The method of claim 23, further including the step of using the interface function block to communicate further data to the external function block to alter the configuration of the external function block.

26. The method of claim 23, further including the steps of allowing a user to configure the control routine by specifying each of a number of function blocks to be used in the control routine, identifying the interconnections between the specified function blocks to be used in the control routine and specifying the location of a particular specified function block as being an internal function block implemented in the controller or the external function block implemented by the field device.

27. The method of claim 26, wherein the step of specifying the location of the particular specified function block as being the external function block includes the step of selecting an external device in which the external function block is to be implemented from a list of external devices connected to the controller.

28. The method of claim 23, wherein the step of storing the data associated with the external function block includes the step of storing an alarm indication generated by the external function block in the interface function block and wherein the method further includes the step of using the alarm indication stored in the interface function block to trigger alarm processing within the controller.

29. The method of claim 23, further including the step of displaying the control routine by displaying a depiction of one or more of the plurality of internal function blocks, a depiction of the shadow function block and depictions of the interconnections between the one or more of the plurality of internal function blocks and the shadow function block so that the interface function block represents the external function block.

32. The method of claim 23, wherein the step of creating an interface function block includes the step of creating the interface function block to automatically communicate with the external function block in a periodic manner.

33. A process routine implemented by a processor, the process routine comprising:

a plurality of interconnected internal function blocks operating within the processor and, communicating according to a first protocol, the plurality of internal function blocks implemented in a scheduled manner;

a shadow function block operating within the processor and communicating with at least one of the plurality of internal function blocks according to the first protocol; and

an external device communicating with the processor via a communications network using a second protocol, the external device further including;

an external function block operating within the external device and communicatively coupled to the shadow function block using the second protocol;

a data transfer between the shadow function block and the external function block, the data transfer operating to mirror at least one input or at least output of the shadow function block to a corresponding input or output of the external function block, or vice versa.