Fisher FIELDVUEDVC6200f Instruction Manual page 74

DVC6200f Digital Valve Controller
Detailed Setup - Transducer Block
February 2017
3. Incoming Pressure Threshold
4. High Friction Breakout Pressure
5. Low Friction Breakout Pressure
D VST Abort Criteria (VST_ABORT_CRITERIA [129.2])
The PST is terminated and the valve is returned to the normal end. The return to the normal end will be per the user
configuration for an aborted test. The abort criteria will only be active if it is added as a criteria to be evaluated during
PST by adding it to the PST Abnormal Criteria.
The device always aborts a PST if the Max Travel displacement is exceeded.
In addition to the above, any of the following can be selected to abort a Partial Stroke Test:
1. Breakout Time
2. Incoming Pressure Threshold
3. High Friction Breakout Pressure
Partial & Full Stroke
D Partial Stroke
PST Max Travel (PST_MAX_TRAVEL [145]) defines how much travel displacement is allowed before the PST aborts (see
figure 4‐7).
PST Minimum Travel is the percentage of total span that the valve moves away from its normal operating end of travel
towards its tripped end of travel during the test. The default value is 10%.
Set Point Overdrive (PST_OVERDRIVE_AMT [144]) defines the extent of the set point overdrive over the Minimum
Travel Movement when the early turn around is enabled. When the early turn around is not enabled it defines the
travel target.
Freeze Analog / Discrete Feedback (PST_OPTIONS [139]) when enabled, freezes the corresponding feedback during a
partial stroke test.
Minimum PST Pause Time, when enabled, the incoming stroke is initiated as soon as the travel reaches the minimum
travel movement. Refer to figure 4‐7 for a time series representation of this parameter.
Randomized PST, when enabled the instrument randomizes the target travel, for each PST.
PST Randomization is defined in percent (%) of calibrated travel span, it defines the extent of randomization from the
minimum travel movement towards the normal end. If the user defined randomization is too large the instrument will
cap the max randomization to ensure that there will be at least 1% travel movement away from the defined normal
end. Refer to figure 4‐6.
Outgoing Ramp Rate is the rate at which the valve will move during the Outgoing stroke of the Partial Stroke test. The
default value is 0.25%/second.
Incoming Ramp Rate is the rate at which the valve will move during the Incoming stroke of the Partial Stroke test. The
default value is 0.25%/second.
PST Return Lead (PST_RETURN_LEAD [149]) defines the percent (%) change in setpoint to overcome the hysteresis in
the valve assembly. The error between setpoint and actual error is added to this percent change. For example, if the
Return Lead is set at 0.5% and there is a 1% error this will be set at 1.5%
PST Breakout Timeout is the user configured amount of time before which the valve must leave the normal end during
a PST.
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Instruction Manual
D103412X012