YOKOGAWA UTAdvanced UP55A, User Manual

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10-8
IM 05P02C41-01EN
10.5 Setting Velocity Limiter to Control Output
Description
Output velocity limiter prevents the control output signal from changing suddenly in order
to protect the control valves (or other actuators) and controlled process.
The output velocity limiter does not work in MAN or RESET mode or when input burnout
or A/D error occurs.
Note that setting an output velocity limit may cancel the effects of derivative action.
The following shows the operation example of output velocity limiter.
100
0
(%)
100%
50 sec
Time (sec)
Output
Velocity limit = 2.0 (%/sec)
Actual output
change
In Heating/cooling control, the output velocity limiter can be set to the control computation
result before split into heating-and cooling-side outputs.
In ON/OFF control, the setting is invalid even if the output velocity limiter is set.
Setting Details
Parameter
symbol
Name
Display
level
Setting range Menu symbol
OPR Output velocity limiter STD
OFF: Disable
0.1 to 100.0%/s
TUNE
Note1: In Cascade control, the LP2 lamp is lit while the Loop-2 parameter is displayed.