Shadow function block interface for use in a process control network

• US 7,519,083 B2
• Filed: 05/18/2004
• Issued: 04/14/2009
• Est. Priority Date: 09/10/1998
• Status: Expired due to Fees

• Current Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Original Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Inventors: Dienstbier, Steve L., Tzovla, Vasiliki, Christensen, Dan D., Stevenson, Dennis L., Jundt, Larry O.
• Primary Examiner(s): Chan; Wing F
• Assistant Examiner(s): Jones; Prenell P
• Application Number:
  US10/848,960
• Publication Number:
  US 20040213285A1
• Time in Patent Office: 1,792 Days
• Field of Search: 370/354, 370/469, 370/474, 370/328, 370/410, 370/465, 370/254, 714/33, 714/37, 714/46, 702/13, 702/16, 700/37, 700/42, 700/48, 700/50, 700/52, 700/54, 700/71, 715/765, 711/162, 711/114, 707/205, 726/1, 710/10, 345/582
• US Class Current: 370/469
• 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 control routine may include a first internal function block for executing a control operation based on an input signal and an information conduit communicatively connected to the first internal function block. The information conduit may have an output adapted to provide the input signal to the first internal function block. The process control routine may further include an external function block communicatively connected to the information conduit and adapted to generate the input signal such that the output signal is directly provided to the information conduit prior to the execution of the control operation.

Claims

1. A process control system comprising:

a first process control device executing a first function block; and

a second process control device executing shadow function block, the second device communicatively connected to the first device;

wherein an output of the first function block is mirrored to an output of the shadow function block, or an input of the first function block is mirrored to an input of the shadow function block.

2. The process control system of claim 1, wherein the shadow function block is adapted to be executed as one of a set of interconnected function blocks within the second process control device.

3. The process control system of claim 1, wherein the first function block and the shadow function block communicate a measurement parameter between the first process control device and the second process control device.

4. The process control system of claim 3 wherein the measurement parameter is a set point.

5. The process control system of claim 3 wherein the measurement parameter is a measured value.

6. The process control system of claim 3 wherein the measurement parameter is a control value.

7. The process control system of claim 3 wherein the measurement parameter is a limit.

8. The process control system of claim 1, wherein the first function block and the shadow function block communicate a status indicator between the first process control device and the second process control device.

9. The process control system of claim 8, wherein the status indicator is a device state.

10. The process control system of claim 8, wherein the status indicator is a function block state.

11. The process control system of claim 1, wherein the first function block and the shadow function block communicate an alarm notification between the first device and the second device.

12. A processor readable medium on which a shadow function block is stored, when executed by a processor the shadow function block adapted to:

receive data from an output of an external device via a first input;

store data received from the external device in a first storage location;

communicate data stored in the first storage location to an input of a control routine via a first output;

receive data from an output of the control routine via;

a second input;

store data received from the output of the control routine in a second storage location; and

communicate data stored in the second storage location to an input of the external device via a second output.

13. The processor readable medium of claim 12, wherein the control routine includes a plurality of interconnected function blocks.

14. The processor readable medium of claim 12, wherein the first storage location is adapted to mirror the stored data to the first output.

15. The processor readable medium of claim 12, wherein the second storage location is adapted to mirror the stored data to the second output.

16. The processor readable medium of claim 12, wherein the first storage location and the second storage location are logical locations defined on a memory.

17. The processor readable medium of claim 12, wherein the first input and the second output communicate according to a first protocol and the first output and the second input communicate according to a second protocol.

18. The processor readable medium of claim 17, wherein the first protocol and the second protocol use synchronous communication.

19. A method of communicating within a process control routine using a function block pair, the method comprising:

creating a first function block to execute on a first device;

creating a shadow function block to execute on a second device providing a communications connection between the second device and the first device;

interacting with one of the first function block or the shadow function block as part of the process control routine;

mirroring an output of the first function block through the communications connection to an output of the shadow function block; and

mirroring an input of the first function block through the communications connection to an input of the shadow function block;

whereby the interaction with the first function block or the shadow function block is reflected in the other of the shadow function block or the first function block.

20. The method of claim 19, wherein creating the shadow function block includes executing the shadow function block as one of a set of interconnected function blocks within the second device.

21. The method of claim 20, wherein executing the shadow function block as one of a set of interconnected function blocks includes defining a process control routine adapted to control a process.

22. The method of claim 19, wherein creating the shadow function block includes creating the shadow function block to conform to the Fieldbus protocol.

23. The method of claim 19, wherein providing the communications connection between the first function block and the shadow function block includes communicating a measurement parameter between the first device and the second device.

24. The method of claim 19, wherein providing the communications connection between the first function block and the shadow function block includes communicating a status indicator between the first device and the second device.

25. The method of claim 19, wherein creating the first function block includes executing the first function block on an external field device.