Travel Calibration; Online Diagnostics; Xd_Error - GE FVP110 Maintenance Manual

Travel Calibration

Travel Calibration
To calibrate the travel of the valve stem, i.e., the stroke of the valve:
1. Set the valve stem to the desired position by changing the value of
FINAL_VALUE.value.
2. Set the AO block and the transducer block to O/S mode.
3. Write the value from the following choices:
❑
1 = off
❑
2 = 0% point calibration. Calibrates only the 0% point and shifts the 100% point
by the delta in the 0% point, while leaving the span unchanged.
❑
3 = span calibration. Calibrates only the 100% point while leaving the 0% point
unchanged.
❑
4 = 50% point calibration. Calibrates at the 50% point while leaving the 0% point
and 100% point unchanged.
The 50%-point calibration (in other words, linearity calibration) is intended to minimize
the linearity error at the 50% point. Also, if the feedback lever slightly deviates from a
horizontal level due to careless FVP110 positioner installation, an error caused by this
shift is corrected by the 50%-point calibration. Carrying out auto tuning of Index 2 or 4
clears the 50% calibration result. Carry out the 50%-point calibration after other tuning
has finished.
The result of Travel calibration, which is written to TRAVEL_ CALIB_RESULT as shown
in Table 35 on page 127, may be an error or warning. An error invalidates the tuning
and does not update the parameter settings.

Online Diagnostics

The FVP110 features functions to diagnose the FVP110 itself and valve actions while
online. The following describes the self-diagnostics function related to the transducer
block.

XD_ERROR

The transducer block performs self-diagnostics and writes the results to the parameter
XD_ERROR. Table 36 shows the meanings of these results in XD_ERROR.
When the content of XD_ERROR or BLOCK_ERR becomes a nonzero value, an alarm
is output to the parameter BLOCK_ALM.
This function strokes the valve over its full range. Do not
WARNING
execute while valve is controlling the process. Keep away
from the movable parts to avoid injury.
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Transducer Block