Wiring fault detection, diagnosis and reporting for process control systems

• US 6,912,671 B2
• Filed: 05/07/2001
• Issued: 06/28/2005
• Est. Priority Date: 05/07/2001
• Status: Active Grant

• Current Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Original Assignee: Bisher-Rosemount Systems Incorporated
• Inventors: Bonwell, Steven D., Christensen, Daniel D, Marshall, Michael L.
• Primary Examiner(s): Iqbal, Nadeem
• Application Number:
  US09/850,300
• Publication Number:
  US 20020194547A1
• Time in Patent Office: 1,513 Days
• Field of Search: 714/25, 714/26, 714/27, 714/32, 714/37, 714/43, 714/47, 714/48, 714/721, 714/742, 714/33, 714/44, 324/513, 324/539, 702/109, 702/122
• US Class Current: 714/25
• CPC Class Codes: G06F 11/0736 in functional embedded systems, i.e. in a data processing system designed as a combination of hardware and software dedicated to performing a certain function testing or monitoring of automated control systems G05B23/02
• CPC Class Codes: G06F 11/079 Root cause analysis, i.e. error or fault diagnosis in a hardware test environment G06F11/22; in a software test environment G06F11/36
• CPC Class Codes: G06F 11/3013 where the computing system is an embedded system, i.e. a combination of hardware and software dedicated to perform a certain function in mobile devices, printers, automotive or aircraft systems testing or monitoring of control systems or parts thereof G05B23/02
• CPC Class Codes: G06F 11/3041 where the computing system component is an input/output interface interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units G06F13/00
• CPC Class Codes: G06F 11/3055 Monitoring arrangements for monitoring the status of the computing system or of the computing system component, e.g. monitoring if the computing system is on, off, available, not available error or fault processing without redundancy G06F11/0703; error detection or correction by redundancy in data representation G06F11/08; error detection or correction by redundancy in operation G06F11/14; error detection or correction by redundancy in hardware G06F11/16
• CPC Class Codes: H04L 12/423 with centralised control, e.g. polling
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

A wiring fault detection, diagnostic and reporting technique enables linking devices within a process control system to measure the electrical characteristics of a segment protocol bus and the electrical characteristics of the signals transmitted via the protocol bus. The technique connects a signal line of a segment protocol bus to one of a plurality of measurement blocks within a wiring fault detection unit. The one of the plurality of measurement blocks measures an electrical characteristic associated with the segment protocol bus and sends the measured electrical characteristic to a wiring fault diagnostic manager. The wiring fault diagnostic manager analyzes the measured electrical characteristic to determine a type of the wiring fault and reports the type of the wiring fault via a user interface.

Claims

1. A system that detects a wiring fault for use within a process control system having a plurality of smart field devices communicatively coupled to a protocol bus, the system comprising:

a linking device that enables a controller to communicate with the plurality of smart field devices, the linking device being further operable to automatically detect a communications problem associated with the protocol bus while the protocol bus is substantially active, and wherein the linking device has a wiring fault detection unit and a wiring fault detection unit residing therein;

the wiring fault detection unit being adapted to be coupled to the protocol bus to measure an electrical characteristic associated with the protocol bus while the protocol bus is substantially active; and

the wiring fault diagnostic manager being communicatively coupled to the wiring fault detection unit and using the measured electrical characteristic to determine a type of the wiring fault.

2. The system of claim 1, wherein the wiring fault detection unit and the wiring fault diagnostic manager reside within a portable unit that is adapted to be locally coupled to the protocol bus.

3. The system of claim 2, wherein the portable unit includes:

a memory;

a processor communicatively coupled to the memory;

a display communicatively coupled to the processor that is adapted to display wiring fault information;

a keypad communicatively coupled to the processor; and

a power source that supplies power to the portable unit.

4. The system of claim 1, wherein the wiring fault detection unit includes a signal switching unit and a plurality of measurement blocks coupled to the signal switching unit.

5. The system of claim 4, wherein the signal switching unit is adapted to be coupled to the protocol bus and to couple a signal line of the protocol bus to one of the plurality of measurement blocks.

6. The system of claim 5, wherein the signal switching unit is further adapted to disconnect the signal line of the protocol bus from a communication circuit.

7. The system of claim 4, wherein the signal switching unit is responsive to signals sent by the wiring fault diagnostic manager.

8. The system of claim 4, wherein the plurality of measurement blocks includes one of an ohmmeter block, a voltmeter block, a signal generator block, a noise meter block, a ground fault detector block, and a capacitance meter block.

9. The system of claim 1, wherein the type of the wiring fault is one of a short circuit, an open circuit, a ground fault, an improper termination, an insufficient signal strength, a poor quality ground connection and an improper supply voltage.

26. The system of claim 1, wherein the automatic detection of the communications problem occurs during an asynchronous communication interval.

10. A method of detecting a wiring fault for use within a process control system having a user interface, a protocol bus, a linking device that enables a controller to communicate with the plurality of smart field devices, and wherein the linking device has a wiring fault detection unit and a wiring fault detection unit residing therein, the wiring fault detection unit including a plurality of measurement blocks and a signal switching unit, the method comprising:

automatically detecting a communications problem associated with the protocol bus while the protocol bus is substantially active;

connecting a signal line of the protocol bus to one of the plurality of measurement blocks;

measuring an electrical characteristic associated with the protocol bus using the one of the plurality of measurement blocks while the protocol bus is substantially active;

sending the measured electrical characteristic to the wiring fault diagnostic manager;

determining a type of the wiring fault based on the measured electrical characteristic; and

automatically reporting the type of the wiring fault to the user interface.

11. The method of claim 10, wherein the step of connecting the signal line of the protocol bus to the one of the plurality of measurement blocks includes the step of connecting the signal line to one of an ohmmeter block, a voltmeter block, a signal generator block, a noise meter block, a ground fault detector block, and a capacitance meter block.

12. The method of claim 10, wherein the step of connecting the signal line of the protocol bus to the one of the plurality of measurement blocks includes the step of connecting the signal line to the one of the plurality of measurement blocks in response to a signal from the wiring fault diagnostic manager.

13. The method of claim 10, wherein the step of measuring the electrical characteristic associated with the protocol bus using the one of the plurality of measurement blocks includes the step of disconnecting the signal line of the protocol bus from a communication circuit.

14. The method of claim 10, wherein the step of measuring the electrical characteristic associated with the protocol bus includes the step of measuring one of a resistance, a capacitance, a signal amplitude, a noise level and a power supply voltage.

15. The method of claim 10, wherein the step of determining the type of the wiring fault based on the measured electrical characteristic includes the step of comparing the measured electrical characteristic to a predetermined value associated with the wiring fault.

16. The method of claim 15, wherein the step of comparing the measured electrical characteristic to the predetermined value includes the step of using a predetermined value associated with one of a short circuit, an open circuit, a ground fault, an improper termination, an insufficient signal strength, a poor quality ground connection and an improper supply voltage.

17. The method of claim 10, wherein the step of automatically reporting the type of the wiring fault to the user interface includes the step of sending wiring fault information to the user interface via a controller.

27. The method of claim 10, wherein automatically detecting the communications problem associated with the protocol bus occurs during an asynchronous communication interval.

18. A system for detecting a wiring fault for use within a process control system having a user interface, a controller, a protocol bus, a processor, and a linking device that enables a controller to communicate with the plurality of smart field devices, the linking device having a wiring fault detection unit and a wiring fault diagnostic manager therein, the wiring fault detection unit including a plurality of measurement blocks and a signal switching unit, the system comprising:

a computer readable medium;

a first routine stored on the computer readable medium and adapted to be executed by the processor that causes the wiring fault detection unit to connect a signal line of the protocol bus to one of the plurality of measurement blocks;

a second routine stored on the computer readable medium and adapted to be executed by the processor that causes the wiring fault detection unit to measure an electrical characteristic associated with the protocol bus using the one of the plurality of measurement blocks while the protocol bus is substantially active;

a third routine stored on the computer readable medium and adapted to be executed by the processor that determines a type of the wiring fault based on the measured electrical characteristic;

a fourth routine stored on the computer readable medium and adapted to be executed by the processor that automatically reports the type of the wiring fault to the user interface; and

a fifth routine stored on the computer readable medium and adapted to be executed by the process that automatically detects a communications problem associated with the protocol bus while the protocol bus is substantially active.

19. The system of claim 18, wherein the second routine is further adapted to cause the wiring fault detection unit to disconnect the signal line of the protocol bus from a communication circuit.

20. The system of claim 18, wherein the second routine is further adapted to measure one of a resistance, a capacitance, a signal amplitude, a noise level and a power supply voltage.

21. The system of claim 18, wherein the third routine is further adapted to compare the measured electrical characteristic to a predetermined value associated with the wiring fault.

22. The system of claim 21, wherein the third routine is further adapted to use a predetermined value associated with one of a short circuit, an open circuit, a ground fault, an improper termination, an insufficient signal strength, a poor quality ground connection and an improper supply voltage.

28. The system of claim 18, wherein the fifth routine automatically detects a communications problem associated with the protocol bus during an asynchronous communication interval.

23. A system that detects a wiring fault for use within a process control system having a controller and a protocol bus, the system comprising:

a plurality of measurement blocks communicatively coupled to the controller and adapted to be coupled to the protocol bus, wherein the controller is programmed to connect one of the plurality of measurement blocks to the protocol bus to detect the wiring fault and wherein the measurement blocks reside within a linking device, wherein the linking device enables the controller to communicate with a plurality of smart field devices, the linking device being operable to automatically detect a communications problem associated with the protocol bus while the protocol bus is substantially active.

24. The system of claim 23, wherein the plurality of measurement blocks includes one of an ohmmeter block, a voltmeter block, a signal generator block, a noise meter block, a ground fault detector block, and a capacitance meter block.

25. The system of claim 23, wherein the wiring fault is one of a short circuit, an open circuit, a ground fault, an improper termination, an insufficient signal strength, a poor quality ground connection and an improper supply voltage.