Transmitter with removable local operator interface

• US 7,525,419 B2
• Filed: 01/30/2006
• Issued: 04/28/2009
• Est. Priority Date: 01/30/2006
• Status: Active Grant

• Current Assignee: Rosemount Incorporated (Emerson Electric Company)
• Original Assignee: Rosemount Incorporated (Emerson Electric Company)
• Inventors: Wells, Christopher A., Schumacher, Mark S., Orth, Kelly M.
• Primary Examiner(s): Edwards, Jr.; Timothy
• Application Number:
  US11/343,058
• Publication Number:
  US 20070191970A1
• Time in Patent Office: 1,184 Days
• Field of Search: 340/506, 340/584, 340/870.07, 714/11, 700/25, 710/264, 702/116
• US Class Current: 340/506
• CPC Class Codes: G01D 18/008 with calibration coefficients stored in memory

Abstract

A process variable transmitter for use with a removable operator interface has a non-volatile memory and a latching component. The non-volatile memory stores device settings. The latching component prohibits changes to transmitter settings if the removable operator interface is absent. Circuitry in the transmitter detects the presence of the removable operator interface. The removable operator interface can include zero and span settings.

Claims

1. A process control device for use with a removable operator interface for use in monitoring or controlling an industrial process comprising:

connectors configured to couple to the removable operator interface;

test circuitry adapted to detect the presence of the removable operator interface coupled to the connectors and provide an output;

a non-volatile memory adapted to store device settings in response to the removable operator interface; and

a latching component adapted to prohibit subsequent changes to stored device settings if the removable operator interface is disconnected from the process device based upon the output from the test circuitry whereby the device settings cannot be changed when the removable operator interface is disconnected from the process device.

2. The apparatus of claim 1 wherein the process device comprises:

an industrial process transmitter adapted to monitor a process variable of an industrial process.

3. The apparatus of claim 1 further comprising:

a bi-directional communications bus adapted to communicatively couple the removable operator interface to the device.

4. The apparatus of claim 3 wherein the bi-directional communications bus is in accordance with the CAN protocol.

5. The apparatus of claim 1 wherein the device settings comprise:

zero and span settings which define a range of output values corresponding to a range of measurement values for a process parameter.

6. The apparatus of claim 1 wherein the device settings comprise an alarm setting.

7. The apparatus of claim 1 wherein the device settings comprise a write protect setting.

8. The apparatus of claim 1 wherein the latching component is implemented in software.

9. The apparatus of claim 1 wherein the testing circuit detects a presence of a diode in the local operator interface.

10. The apparatus of claim 1 wherein the testing circuit periodically tests for the presence of the removable operator interface.

11. A method in a process device for storing device settings, comprising:

attaching a local operator interface to the process device;

detecting a connection between the local operator interface and the process device;

reading a manual input from the local operator interface;

storing device settings in the process device in response to the manual input if the local operator interface is detected by the step of detecting; and

latching the stored devices settings and prohibiting subsequent changes to the device settings stored whereby the device settings cannot be changed if the local operator interface is removed from the process device based upon the step of detecting.

12. The method of claim 11 including monitoring a process variable of an industrial process.

13. The method of claim 11 further comprising:

bi-directional communicating with adapted removable operator interface.

14. The method of claim 13 wherein the bi-directional communicating is in accordance with the CAN protocol.

15. The method of claim 11 wherein the device settings comprise:

zero and span settings defining a range of output values corresponding to a range of measurement values for a process parameter.

16. The method of claim 11 wherein the device settings comprise an alarm setting.

17. The method of claim 11 wherein the device settings comprise a write protect setting.

18. The method of claim 11 including implementing the step of latching in software.

19. The method of claim 11 wherein detecting a connection comprises detecting a diode in the local operator interface.