Process transmitter with wireless communication link

• US 6,839,546 B2
• Filed: 04/22/2002
• Issued: 01/04/2005
• Est. Priority Date: 04/22/2002
• Status: Active Grant

• Current Assignee: Rosemount Incorporated (Emerson Electric Company)
• Original Assignee: Rosemount Incorporated (Emerson Electric Company)
• Inventors: Hedtke, Robert C.
• Primary Examiner(s): MILORD, MARCEAU
• Application Number:
  US10/128,769
• Publication Number:
  US 20040203421A1
• Time in Patent Office: 988 Days
• Field of Search: 455/67.11, 455/68, 455/67.12, 455/90.3, 455/78, 455/575.1, 455/74, 737/06, 702/127, 702/138, 340/870.01, 340/870.39, 340/870.16
• US Class Current: 455/67.11
• CPC Class Codes: G01D 3/08 with provision for safeguarding the apparatus, e.g. against abnormal operation, against breakdown
• CPC Class Codes: G01D 5/12 using electric or magnetic means G01D5/06 takes precedence

Abstract

A process transmitter is configured to measure a process variable of an industrial process. A housing has a first cavity which houses first transmitter electronic circuitry and provides a barrier between the first transmitter electronic circuitry and second transmitter electronic circuitry. A non-physical electromagnetic link between the first transmitter electronic circuitry and the second transmitter electronic circuitry configured to carry data therebetween.

Claims

1. A process transmitter configured to measure a process variable of an industrial process, comprising:

a process variable sensor configured to sense the process variable and responsively provide a process variable sensor output;

first transmitter electronic circuitry coupled to the process variable sensor;

second transmitter electronic circuitry configured to cooperate with the first transmitter electronic circuitry;

a two-wire process control loop coupling configured to provide power to the circuitry from a two-wire process control loop;

a housing having a first cavity housing the first transmitter electronic circuitry, the housing including a barrier between the first transmitter electronic circuitry and the second transmitter electronic circuitry; and

a non-physical electromagnetic link between the first transmitter electronic circuitry and the second transmitter electronic circuitry configured to carry data therebetween.

2. The apparatus of claim 1 wherein the non-physical electromagnetic link comprises a radio frequency (RF) link.

3. The apparatus of claim 2 including first and second antennas coupled to respective first and second transmitter electronic circuitry.

4. The apparatus of claim 1 wherein the non-physical electromagnetic link comprises a capacitive coupling.

5. The apparatus of claim 4 including first and second capacitive plates positioned proximate one another on opposed sides of the barrier, the first and second capacitive plate coupled to respective first and second transmitter electronic circuitry.

6. The apparatus of claim 1 wherein the non-physical electromagnetic link comprises an inductive coupling.

7. The apparatus of claim 6 including first and second inductors positioned proximate one another on opposed sides of the barrier, the first and second inductors coupled to respective first and second transmitter electronic circuitry.

8. The apparatus of claim 1 wherein the second transmitter electronic circuitry comprises a display.

9. The apparatus of claim 1 wherein the second transmitter electronic circuitry comprises a manual input.

10. The apparatus of claim 1 wherein the first and second electronic circuitry couple to the two-wire process control loop.

11. The apparatus of claim 1 wherein the second transmitter electronic circuitry is positioned within the housing.

12. The apparatus of claim 1 wherein the second transmitter electronic circuitry is spaced apart from the housing.

13. The apparatus of claim 1 wherein the data comprises a process variable.

14. The apparatus of claim 1 wherein the data comprises calibration data.

15. The apparatus of claim 1 wherein the data comprises programming data.

16. The apparatus of claim 1 wherein the data comprises configuration data.

17. The apparatus of claim 1 wherein the second transmitter electronic circuitry is completely powered by the first transmitter electronic circuitry over the non-physical electromagnetic link.

18. A process monitoring system comprising:

process transmitter configured to measure a process variable of an industrial process, comprising;

a process variable sensor configured to sense the process variable and responsively provide a process variable sensor output;

first transmitter electronic circuitry coupled to the process variable sensor;

a two-wire process control loop coupling configured to provide power to the circuitry from a two-wire process control loop;

a housing having a first cavity housing the first transmitter electronic circuitry, the housing including a barrier between the first transmitter electronic circuitry;

second transmitter electronic circuitry spaced apart from the process transmitter configured to cooperate with the first transmitter electronic circuitry; and

a non-physical electromagnetic link between the first transmitter electronic circuitry and the second transmitter electronic circuitry configured to carry data therebetween.

19. The apparatus of claim 18 wherein the second transmitter electronic circuitry is configured to communicate with a plurality of first transmitter electronic circuitry in a plurality of transmitters through a plurality of non-physical electromagnetic links.

20. The apparatus of claim 19 wherein the second transmitter electronic circuitry comprises a display to display data from the plurality of transmitters.

21. A method of providing an output from a transmitter, comprising:

coupling first transmitter electronic circuitry to a process variable sensor configured to sense a process variable;

enclosing the first transmitter electronic circuitry in a hermetically sealed cavity;

placing second transmitter electronic circuitry outside the cavity, the second transmitter electronic circuitry separated from the first electronic circuitry by a barrier;

providing loop connections to couple the transmitter to a two-wire process control loop, the transmitter configured to be completely powered from the process control loop; and

coupling the first transmitter electronic circuitry to the second transmitter electronic circuitry by a non-physical electromagnetic link.

22. The method of claim 21 wherein the second transmitter electronic circuitry comprises a display.

23. The method of claim 21 wherein the second transmitter electronic circuitry comprises a manual input.

24. The method of claim 21 wherein the non-physical electromagnetic link comprises a radio frequency (RF) link.

25. The method of claim 21 wherein the non-physical electromagnetic link comprises a capacitive coupling.

26. The method of claim 21 wherein the non-physical electromagnetic link comprises an inductive coupling.

27. The method of claim 21 wherein the second transmitter electronic circuitry is completely powered by power received over the non-physical electromagnetic link.

28. The method of claim 21 including transmitting process variable data over the non-physical electromagnetic link.

29. The method of claim 21 including transmitting calibration data over the non-physical electromagnetic link.

30. The method of claim 21 including transmitting programming data over the non-physical electromagnetic link.

31. The method of claim 21 including transmitting configuration data over the non-physical electromagnetic link.