Apparatus and method for diagnosing faults in a fieldbus interface module

Patent metadata

Field	Value
Publication number	US-11449403-B2
Application number	US-201916597516-A
Country	US
Kind code	B2
Filing date	Oct 9, 2019
Priority date	Oct 9, 2019
Publication date	Sep 20, 2022
Grant date	Sep 20, 2022

Abstract

A method and system for detecting faults in a communication interface is disclosed. The communication interface is connected to a field device and a device bus comprising generating periodic diagnostic pulse by a programing unit. The programming unit is communicatively connected to the controller and a controller interface and provides the diagnostic pulse to a multiplexer to periodically apply the diagnostic pulses from the programming unit to a first winding of a transformer. The programming unit provides the diagnostic pulse to the isolation unit. A sensing unit senses a voltage drop across a sense resistor, the sensing unit having an input connected to the sense resistor and an output connected to the programming unit. The sensing unit communicates a sense signal based on the comparison to the programming unit, and switches from a primary or a secondary module to the other based on the sense signal.

First claim

The invention claimed is:

1. An apparatus for detecting faults in a communication interface, the communication interface connected to a field device and a device bus, the apparatus comprising:
a) a controller configured to generate a device bus communication signal;
b) a programming unit communicatively connected to the controller and a controller interface, the programming unit configured to:
a. detect faults in the communication interface; and
b. generate periodic diagnostic pulses;

c) a transformer having a first winding connected to the controller interface and a second winding connected to the device bus;
d) a multiplexer connected to the programming unit configured to periodically apply the diagnostic pulses from the programming unit to the first winding;
e) an isolation unit connected to the programming unit configured to periodically apply the diagnostic pulses from the programming unit to the second winding,
f) a sense resistor connected in series to the first winding of the transformer; and
g) a sensing unit connected to the sense resistor and the programming unit, wherein the sensing unit is arranged to determine a voltage across the sense resistor, communicating the sensed voltage to the programming unit.

2. The apparatus of claim 1 , wherein the programming unit is configured to:
receive a field bus communication signal from the controller.

3. The apparatus of claim 1 , wherein the programming unit is configured to:
generate a diagnostic pulse based on a field bus communication signal.

4. The apparatus of claim 1 , wherein the programming unit is configured to:
detect a fault in the transformer based on a signal from sensing unit.

5. The apparatus of claim 1 , wherein the sensing unit comprises an amplifier and a comparator.

6. The apparatus of claim 1 , wherein the isolation unit comprises an optocoupler.

7. The apparatus of claim 1 , wherein the controller interface is communicatively connected to the multiplexer and the controller.

8. A method for detecting faults in a communication interface, the communication interface connected to a field device and a device bus, the method comprising:
a) generating periodic diagnostic pulse by a programing unit, the programming unit communicatively connected to a controller and a controller interface,
b) providing the diagnostic pulse to a multiplexer to periodically apply the diagnostic pulse from the programming unit to a first winding of a transformer;
c) providing the diagnostic pulse to an isolation unit to periodically pass the diagnostic pulse from the programming unit to a second winding of the transformer;
d) sensing a voltage drop across a sense resistor, a sensing unit having an input connected to the sense resistor and an output connected to the programming unit;
e) comparing the voltage drop across the sense resistor with a reference value voltage value;
f) communicating a sense signal based on the comparison to the programming unit; and
g) switching from one of a primary or a secondary module to other of the one of the primary or the secondary module, based on the sense signal.

9. The method of claim 8 further comprises:
generating a field bus communication signal by the controller; and
receiving the field bus communication signal at the programming unit.

10. The method of claim 9 , wherein generating the periodic diagnostic pulse comprises:
generating the diagnostic pulse based on the field bus communication signal.

11. The method of claim 8 , wherein the switching comprises:
detecting a fault in the transformer based on a signal from sensing unit.

12. The method of claim 8 , wherein the comparing comprises:
amplifying the voltage drop across the sense resistor.

13. The method of claim 8 , wherein providing the diagnostic pulse to an isolation unit comprises:
shorting the second winding of the transformer by periodically passing the diagnostic pulse to the second winding of the transformer.

14. A system for detecting faults in a communication interface, the communication interface connected to a field device and a device bus, the system comprising:
at least a programming unit configured to:
a) generate periodic diagnostic pulse by the programing unit, the programming unit communicatively connected to a controller and a controller interface,
b) provide the diagnostic pulse to a multiplexer to periodically apply the diagnostic pulse from the programming unit to a first winding of a transformer; and
c) provide the diagnostic pulse to an isolation unit to periodically pass the diagnostic pulse from the programming unit to a second winding of the transformer; and
at least a sensing unit configured to:

d) sense a voltage drop across a sense resistor, the sensing unit having an input connected to the sense resistor and an output connected to the programming unit;
e) compare the voltage drop across the sense resistor with a reference value voltage value;
f) communicate a sense signal based on the comparison to the programming unit; and
g) switch from one of a primary or a secondary module to other of the one of the primary or the secondary module, based on the sense signal.

15. The system of claim 14 , wherein the programming unit is configured to:
receive a field bus communication signal from the controller and generate the diagnostic pulse based on the field bus communication signal.

16. The system of claim 14 , wherein the programming unit is configured to:
detect a fault in the transformer based on a signal from sensing unit.

17. The system of claim 14 , wherein the sensing unit comprises of an amplifier and a comparator.

18. The system of claim 14 , wherein the isolation unit comprises of an optocoupler.

19. The system of claim 14 , wherein the controller interface is communicatively connected to the multiplexer and the controller.

20. The system of claim 14 , wherein the isolation unit:
shorts the second winding of the transformer by periodically passing the diagnostic pulse to the second winding of the transformer.

Assignees

• Honeywell Int Inc

Inventors

• Kulkarni Amit
• Patil Ganesh Ratilal
• Rizwan Mohammed
• Kant Vimal

Classifications

• G06F11/3027

  where the computing system component is a bus · CPC title

• G06F11/0754

  by exceeding limits · CPC title

• G06F11/221 Primary

  to test buses, lines or interfaces, e.g. stuck-at or open line faults · CPC title

• G06F11/349

  for interfaces, buses · CPC title

• G06F11/2007

  using redundant communication media · CPC title