YOKOGAWA UTAdvanced UP55A, User Manual

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8-60
IM 05P02C41-01EN
8.4.5 Switching PID According to Deviation (Reference Deviation)
Description
The zone PID selection by deviation switches between the groups of PID parameters
according to the amount of deviation.
This function is called “reference deviation.”
In the fixed point control, if the actual amount of deviation exceeds the setpoint of the
reference deviation, the controller automatically changes to the PID parameter group
(PID of group R) set for the zone. If the actual amount of deviation becomes smaller than
the setpoint of reference deviation, the controller changes to the PID parameter group
appropriate for the zone.
For example, if the deviation is large, PV can be reached more rapidly to SP by
increasing the proportional gain (i.e., narrowing the proportional band). Switching PID
according to deviation is effective when ZON is set to 1, 2, 4. The zone PID selection by
reference deviation has priority over other zone PID selections.
Reference deviation (RDV)
Reference deviation (RDV)
Reference point 2
Reference point 1
Minimum value of
PV input range
SP
PID of group R PID of group R
PID of group 2
PID of group R: PID for reference deviation
PID of group 2
PV
Maximum value of
PV input range
PID No. to be selected
Setting Details
Parameter
symbol
Name
Display
level
Setting range Menu symbol
ZON
Zone PID
selection
STD
0: Segment PID selection
1: Zone PID selection (selection
by PV)
2: Zone PID selection (selection
by target SP)
4: Zone PID selection (selection
by SP)
5: Local PID selection
CTL
RDV
Reference
deviation
STD
OFF: Disable
0.0 + 1 digit to 100.0% of PV input
range span (EUS)
ZONE
PID
PID number
(display only)
EASY
1 to 8, R: PID group for reference
deviation
MODE
Note1: In Cascade control, the LP2 lamp is lit while the Loop-2 parameter is displayed.
Note2: A currently-used PID number is displayed for the parameter PID.
8.4 Switching PID