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Function Blocks
PID Function Block
Revision 11
HC900 Hybrid Control Designer Function Block Reference Guide
281
2/07
Table 83 PID Tuning
t
ab configuration parameters
Properties Group
Parameter
Index #
Parameter Description
Value or Selection
Tuning Constants
Prop Band
0
PB1 or
Gain1
Proportional Band (PB) - is the
percentage of the range of the
measured variable for which a
proportional controller will produce
a 100 % change in its output.
0.1 to 1000
or
Gain
36
PB2 or
Gain2
Gain - is the ratio of output change
(%) over the measured variable
change (%) that caused it.
G =
100 %
PB %
where PB is the proportional Band
(in %)
0.1 % to 1000 %
ATTENTION: Enter
values for tuning set 1
and tuning set 2 in
specified fields.
Reset
Minutes
or
Repeats per
Minute
2
Reset1
or
38
Reset2
RESET (Integral Time) - adjusts the
controller’s output according to both
the size of the deviation (SP-PV)
and the time it lasts. The amount of
corrective action depends on the
value of Gain.
The reset adjustment is measured
as how many times proportional
action is repeated per minute
(Repeats/minute) or how many
minutes before one repeat of the
proportional action occurs
(Minutes/repeat).
0.02 to 50.00
Must be enabled for
PID-B or DUP-B
algorithm selections.
Rate
Minutes
1
Rate1
or
37Rate
2
RATE action, in minutes affects the
controller’s output whenever the
deviation is changing; and affects it
more when the deviation is
changing faster.
0 or 0.1 to 10.00
minutes
0 = OFF
Feedforward Gain
Feedforward
Gain
43
Applies Gain to the feedforward
value (FFV). Feedforward Input is
multiplied by this value.
0.0 to 10.0
Manual Reset
Manual
Reset
32
MANUAL RESET- is only
applicable if you do not use RESET
(Integral Time)
Allows correction of output to
account for load changes to bring
the PV up to setpoint.
–100 to 100
(in % of Output)