System for preserving and displaying process control data associated with an abnormal situation

• US 7,702,401 B2
• Filed: 09/05/2007
• Issued: 04/20/2010
• Est. Priority Date: 09/05/2007
• Status: Active Grant

• Current Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Original Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Inventors: Westbrock, Jon, Eryurek, Evren
• Primary Examiner(s): Patel; Ramesh B
• Application Number:
  US11/899,213
• Publication Number:
  US 20090062933A1
• Time in Patent Office: 958 Days
• Field of Search: 700/12, 700/19, 700/21, 700/51, 700 79- 80, 702181-184
• US Class Current: 700/21
• CPC Class Codes: G05B 23/0264 Control of logging system, e.g. decision on which data to store; time-stamping measurements
• CPC Class Codes: G05B 23/0272 Presentation of monitored results, e.g. selection of status reports to be displayed; Filtering information to the user

Abstract

A system for preserving process variable data relating to the operation of a process is provided. The system is adapted to preserve process variable data obtained before, during, and after the occurrence of an abnormal situation or event. The preserved process variable data maybe communicated from smart field devices or other intelligent equipment relating to the control of the process to a process controller or other higher level control device. The process controller or other higher level control device may then cause the preserved data to be displayed for an operator or other maintenance personnel. The preserved data may also be provided to other process control modules or abnormal situation prevention systems for further analysis to develop methods for preventing the abnormal situation from recurring in the future, or for taking additional steps based on the abnormal situation data to minimize or prevent a further deterioration of the process operation.

Claims

1. A system for processing data related to an abnormal process event in a controlled process, the system comprising:

a controller

a communication channel; and

an intelligent process control field device having a processor, a memory, and an input device, the input device adapted to measure process variable data, the processor configured to temporarily store statistical data related to the measured process variable data in the memory at a first sample rate, upon detection of an abnormal process event the processor further configured to preserve a portion of the statistical data temporarily stored in the memory, the preserved portion of the statistical data corresponding to a time period beginning before the abnormal process event, and to communicate the preserved portion of the statistical data to the controller over the communication channel at a second sample rate.

2. The system of claim 1 wherein preserved portion of the statistical data stored in the memory and communicated to the controller corresponds to a time period ending after the occurrence of the abnormal process event.

3. The system of claim 2 wherein the processor is further configured to transmit the preserved portion of the statistical data at a time after the occurrence of the abnormal event.

4. The system of claim 3 wherein the processor is adapted to transmit the preserved portion of the statistical data in a plurality of data packets.

5. The system of claim 1 further comprising a display device and an interface application, the interface application adapted to cause at least a portion of the statistical data related to the process variable data communicated to the controller to be displayed on the display device.

6. The system of claim 1 wherein statistical data related to the process variable data comprise the process variable data received by the input device.

7. The system of claim 1 wherein statistical data related to the process variable data comprise statistical values calculated from the process variable data received by the input device.

8. The system of claim 1 wherein the first sample rate is greater than the second sample rate at which the statistical data stored in the memory are communicated to the controller.

9. The system of claim 1 wherein the processor is further configured to temporarily store the statistical data in the memory corresponding to a moving time window of a defined length, such that the statistical data stored in the memory corresponds to process variable data received over a period of time corresponding to the length of the moving time window.

10. The system of claim 9 wherein the defined length of the moving time window is selected dynamically based on an abnormal condition to which the process variable data relate.

11. A smart device for controlling at least one aspect of a process, the smart device comprising:

a memory;

an input adapted to receive process variable data; and

a processor configured to temporarily store statistical data associated with the received process variable data in the memory at a first data sample rate, and upon the detection of an abnormal process event to preserve a portion of the statistical data stored in the memory and to thereafter communicate the preserved statistical data to an external device at a second data sample rate.

12. The smart device of claim 11 wherein the first data sample rate is greater than the second data sample rate.

13. The smart device of claim 11 wherein the processor is further configured to store the statistical data in the memory according to a moving time window of a predetermined length, such that the memory stores statistical data for a period of time corresponding to the length moving time window.

14. The smart device of claim 13 wherein the statistical data are stored in the memory on a first-in first-out basis such that older statistical data received and stored in the memory at a time corresponding to a trailing edge of the moving time window are discarded as new data received at a time corresponding to a leading edge of the moving time window are stored in the memory.

15. The smart device of claim 11 wherein the processor is further configured to detect the occurrence of an abnormal event.

16. The smart device of claim 15 wherein the processor is further configured to preserve a portion of the statistical data stored in the memory corresponding to a predefined period of time before the occurrence of the abnormal event, and a predefined period of time following the occurrence of the abnormal event.

17. The smart device of claim 16 wherein the predefined period of time is determined dynamically based on a current operating state of the process.

18. The smart device of claim 16 wherein the processor is further configured to communicate the portion of the statistical data stored in the memory at a time following the occurrence of the abnormal event.

19. The smart device of claim 16 wherein the processor is further configured to communicate the portion of the statistical data stored in the memory via a plurality of data packets.

20. A method of preserving process control data associated with an abnormal situation, the method comprising:

receiving process variable data associated with a process;

temporarily storing statistical data associated with the received process variable data in a memory at a first data sample rate;

detecting an abnormal situation associated with the process;

preserving a portion of the statistical data stored in the memory in response to the abnormal situation; and

communicating the preserved portion of the statistical data associated with the received process control data over a communication channel at a second data sample rate.

21. The method of claim 20 further comprising displaying the preserved portion of the statistical data communicated over the communication channel on an interface device.

22. The method of claim 20 further comprising analyzing the preserved portion of the statistical data communicated over the communication channel to determine a cause of the abnormal situation.

23. The method of claim 20 wherein temporarily storing statistical data associated with received process variable data comprises defining a moving time window of a predetermined length, wherein statistical data are continually written to a memory as they become available, and wherein the statistical data are stored in the memory for a length of time at least equal to the length of the moving time window.

24. The method of claim 20 wherein the first data sample rate is greater than the second data sample rate.

25. The method of claim 20 wherein communicating the preserved portion of the statistical data over a communication channel comprises communicating a plurality of data packets each including an amount of data smaller than the preserved portion of the statistical data.

26. The method of claim 20 wherein preserving a portion of the statistical data comprises preserving a first portion of the statistical data corresponding to a predetermined length of time before the abnormal situation was detected, and preserving a second portion of the statistical data corresponding to a predetermined length of time after the abnormal situation was detected.