Field device calibration

• US 8,364,431 B2
• Filed: 10/12/2007
• Issued: 01/29/2013
• Est. Priority Date: 10/13/2006
• Status: Active Grant

• Current Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Original Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Inventors: Russell, Alden C., Dewey, Alan R.
• Primary Examiner(s): Khuu, Cindy Hien-Dieu
• Assistant Examiner(s): Ngon, Ricky
• Application Number:
  US11/974,418
• Publication Number:
  US 20080091376A1
• Time in Patent Office: 1,936 Days
• Field of Search: 702/85, 702 86-108, 702/116, 702121-123
• US Class Current: 702/85
• CPC Class Codes: G01D 18/00 Testing or calibrating apparatus or arrangements provided for in groups G01D1/00 - G01D15/00
• CPC Class Codes: G05B 2219/25428 Field device
• CPC Class Codes: G05B 2219/31181 Controller and device have several formats and protocols, select common one
• CPC Class Codes: G05B 2219/33331 Test, diagnostic of field device for correct device, correct parameters

Abstract

A calibrator for field devices is provided. In one aspect, the calibrator has the ability to communicate in accordance with at least two process communication protocols, and tests an attached process connection before engaging communication. In another aspect, the calibrator includes isolation circuitry to facilitate compliance with at least one intrinsic safety requirement, while communicating with field devices using an all-digital process communication protocol. In another aspect, a method of calibrating field devices is provided which accesses device descriptions of the field devices to generate calibration tasks.

Claims

1. A calibrator for calibrating a separate field device that only communicates digitally, the calibrator being separate from the field device and comprising:

a first connection operably coupleable to the separate field device;

a calibration source for generating a suitable calibration output through the first connection to the separate field device as part of a calibration routine;

a second connection;

isolation circuitry operably coupleable to the separate field device through the second connection;

a loop communication module coupled to the isolation circuitry, the loop communication module being configured to communicate with the separate field device in accordance with at least one all-digital process communication protocol; and

a controller coupled to the loop communication module, the controller being configured to communicate with and calibrate the separate field device through the loop communication module by automatically selectively generating an adjustment to the separate field device that is provided to the separate field device through the second connection.

2. The calibrator of claim 1, wherein the calibrator is intrinsically safe.

3. The field device of claim 1, and further comprising measurement circuitry coupled to at least one sensor to sense the known physical input.

4. The field device of claim 3, wherein the measurement circuitry includes an analog-to-digital converter.

5. A system for calibrating a separate field device, the system being separate from the field device and comprising:

a calibrator including;

a first connection operably coupleable to the separate field device;

a loop communication module configured to communicate with the separate field device through the first connection in accordance with an all-digital process industry standard communication protocol;

a controller operably coupled to the loop communication module, the controller being configured to communicate with and calibrate the separate field device through the loop communication circuitry by automatically selectively generating an adjustment to the separate field device;

memory coupled to the controller and configured to store information relative to at least one calibration;

short range wireless input/output communication circuitry; and

a first universal source separate from the calibrator, the first universal source including;

short range wireless input/output communication circuitry configured to communicate with the short range input/output communication circuitry of the calibrator;

a controller coupled to the short range input/output communication circuitry; and

an output control module coupled to the controller and configured to generate a physical output signal to the separate field device through a second connection based on an instruction from the controller.

6. The system of claim 5, and further comprising a second universal source.

7. A method of calibrating a field device, the method comprising:

coupling a first connection of a calibrator to a field device that is separate from the calibrator;

accessing a device description of the field device;

generating at least one calibration task based upon the device description of the field device;

executing the at least one calibration task by generating a known input to the field device through a second connection of the calibrator and automatically selectively generating an adjustment to the separate field device through the first connection of the calibrator;

communicating with the field device to determine the field device'"'"'s measurement corresponding to the known input; and

determining if the field device'"'"'s measurement is sufficiently close to the known value of the input.

8. The method of claim 7, wherein the device description is loaded into the calibrator prior to coupling the calibrator to the field device.

9. The method of claim 7, wherein the device description is an Electronic Device Description Language (EDDL) description.

10. The method of claim 7, wherein communicating with the field device is done completely digitally.