YOKOGAWA UP35A, User Manual

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8-30
IM 05P02D41-01EN
8.6 Suppressing Hunting (Super2 Function)
Description
The Super2 function suppresses the hunting effect of the controller without re-tuning the
PID parameters.
Hunting means the PV becomes unstable and oscillates around SP.
SUPER2 = ON
Hunting
PV SP PV
● In hunting condition, the Super2 function selects the output from process model as PV
signal.
● The process model removes a factor of dead time from the actual process.
● The real process is under the open-loop condition.
● After hunting is suppressed, the Super2 function selects real PV signal, and carry out
the standard feedback control.
PID control
SP
OUT PV
CPV
Process
PV
Process
model
+
–
Effects of Super2
SUPER2 = ON
SUPER2 = ON
Hunting
Hunting
PV
PV
SP PV
Load change
Temperature change
PID parameters are set at this condition.