Travel Calibration; Auto Calibration - Fisher FIELDVUE DVC6200 Instruction Manual

Calibration
February 2017

Travel Calibration

If a double‐acting relay is used, you will be prompted to run the relay adjustment when auto or manual calibration is
selected. Select Yes to adjust the relay, select No to proceed with calibration. For additional information, refer to Relay
Adjustment on page 43.

Auto Calibration

1. The auto calibration procedure is automatic. It is completed when the Calibration menu appears.
During calibration, the instrument seeks the high and low end points and the minor loop feedback (MLFB) and output
bias. By searching for the end points, the instrument establishes the limits of physical travel, i.e. the actual travel 0 and
100% positions. This also determines how far the relay beam swings to calibrate the sensitivity of the MLFB sensor.
2. Place the instrument In Service and verify that the travel properly tracks the current source.
If the unit does not calibrate, refer to table 4‐1 for error messages and possible remedies.
Table 4‐1. Auto Calibrate Travel Error Messages
Error Message
Power failure occurred during Auto Calib
Auto Calib did not complete within the time limit.
Insufficient travel
Drive signal exceed low limit; check supply
pressure
Drive signal exceed high limit; check supply
pressure
38
The analog input signal to the instrument must be greater than 3.8 mA. Adjust the current output
from the control system or the current source to provide at least 4.0 mA.
The problem may be one or the other of the following:
1. The tuning set selected is too low and the valve does not reach an end point in the allotted time.
Select Manual Setup > Tuning > Travel Tuning > Stabilize/Optimize then Increase Response (selects next
higher tuning set).
2. The tuning set selected is too high, valve operation is unstable and does not stay at an end point
for the allotted time. Select Manual Setup > Tuning > Travel Tuning > Stabilize/Optimize then Decrease
Response (selects next lower tuning set).
Prior to receiving this message, did the instrument output go from zero to full supply? If not, verify
instrument supply pressure by referring to the specifications in the appropriate actuator instruction
manual. If supply pressure is correct, check instrument pneumatic components (I/P converter and
relay).
If the instrument output did go from zero to full supply prior to receiving this message, then verify
proper mounting by referring to the appropriate mounting procedure in the Installation section and
checking the magnet array for proper alignment.
1. Check supply pressure (reverse‐acting relay)
2. Friction is too high.
1. Check supply pressure (direct‐acting relay)
2. Friction is too high
Possible Problem and Remedy
Instruction Manual
D103605X012