Field device calibration
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.
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.