Manual Calibration; Analog Calibration Adjust - Fisher FIELDVUE DVC6200 Instruction Manual

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
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 beam position 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 5-1 for error
messages and possible remedies.

Manual Calibration

Two procedures are available to manually calibrate
travel:
D Analog Adjust
D Digital Adjust

Analog Calibration Adjust

From the Calibrate menu, select Travel Calibration,
Manual Calibration, and Analog Adjust.
Connect a variable current source to the instrument
LOOP + and LOOP − terminals. The current source
should be capable of generating 4 to 20 mA.
Follow the prompts on the Field Communicator display
to calibrate the instrument's travel in percent.
September 2010
Table 5-1. Auto Calibrate Travel Error Messages
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. Press the Hot Key, select 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. Press the Hot Key, select 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.
Verify travel sensor adjustment by performing the appropriate Travel Sensor Adjust procedure in
the Calibration section.
1. Check supply pressure (reverse-acting relay)
2. Friction is too high.
1. Check supply pressure (direct-acting relay)
2. Friction is too high
1. Adjust the input current until the valve is near
mid-travel. Press OK.
2. Adjust the current source until the valve is at 0%
travel, then press OK.
3. Adjust the current source until the valve is at 100%
travel, then press OK.
4. Adjust the current source until the valve is at 0%
travel, then press OK.
5. Adjust the current source until the valve is at 100%
travel, then press OK.
6. Adjust the current source until the valve is at 5%
travel, then press OK.
7. Adjust the current source until the valve is at 95%
travel, then press OK.
8. Place the instrument In Service and verify that the
travel properly tracks the current source.
Possible Problem and Remedy
Note
0% Travel = Valve Closed
100% Travel = Valve Open
Note
In steps 4 through 7 the accuracy of
the current source adjustment affects
the position accuracy.
Calibration
5
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