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IDEC SmartRelay functions
225
IDEC SmartRelay Manual
Parameter p (number of decimals)
Applies only to the PV, SP, Min and Max values displayed in
a message text.
Timing diagram
The nature, manner and speed with which the AQ changes
depend on the parameters KC and TI. Thus, the course of
AQ in the diagram is merely an example. A control action is
continuous; therefore the diagram portrays just an extract.
1
2
3
A/M
R
Dir
AQ
Mq
500 ms
Min
Max
PV
SP
/+
/–
Q
1. A disturbance causes the PV to drop, as Dir is positioned
upwards, AQ increases until PV corresponds again to
SP.
2. A disturbance causes the PV to drop, as Dir is positioned
downwards, AQ decreases until PV corresponds again
to SP.
It is not possible to change the direction (Dir) at runtime
of the function. The change is shown here for illustrative
purposes only.
3. As AQ is set to 0 by means of the input R, PV changes.
This is based on the fact that PV increases, which on
account of Dir = upwards causes AQ to drop.
Courtesy of Steven Engineering, Inc. ● 230 Ryan Way, South San Francisco, CA 94080-6370 ● General Inquiries: (800) 670-4183 ● www.stevenengineering.com