Omron SYSMAC CJ - REFERENCE MANUAL 01-2008 Reference Manual page 814

Data Control Instructions
Precautions
PID Parameter Settings
Control Item
data
C Set value (SV)
C+1 Proportional band
C+2 Tik
Integral Constant
C+3 Tdk
Derivative Constant
C+4 Sampling period ( )
Bits 04 to 15 2-PID parameter ( ) The input filter coefficient. Nor-
of C+5
Bit 03 of C+5 Manipulated vari-
able output designa-
tion
Bit 01 of C+5 PID constant
change enable set-
ting
PIDAT(191) is executed as if the execution condition was a STOP-RUN signal.
PID calculations are executed when the execution condition remains ON for
the next cycle after C+11 to C+40 are initialized. Therefore, when using the
Always ON Flag (ON) as an execution condition for PIDAT(191), provide a
separate process where C+11 to C+40 are initialized when operation is
started.
If the C data is out of range, an error will occur and the Error Flag will turn ON.
If an error occurred during autotuning, the Error Flag will turn ON.
If the actual sampling period is more than twice the designated sampling
period, an error will occur and the Error Flag will turn ON. PID control will still
be executed, however.
The Carry Flag turns ON while PID control is being executed.
The Greater Than Flag turns ON if the manipulated variable after the PID
action exceeds the upper limit. At this time, the results are output at the upper
limit.
The Less Than Flag turns ON if the manipulated variable after the PID action
is below the lower limit. At this time, the results are output at the lower limit.
Contents
The target value of the process
being controlled.
The parameter for P action
expressing the proportional con-
trol range/total control range.
A constant expressing the
strength of the integral action. As
this value increases, the integral
strength decreases.
A constant expressing the
strength of the derivative action.
As this value increases, the
derivative strength decreases.
Sets the period for executing the
PID action.
mally use 0.65 (i.e., a setting of
000). The filter efficiency
decreases as the coefficient
approaches 0.
Designates the manipulated vari-
able output for when the PV
equals the SV.
The timing of enabling changes
made to the proportional band
(P), integral constant (Tik), and
derivative constant (Tdk) for use
in PID calculations.
Setting range
Binary data (of the same number
of bits as specified for the input
range)
0001 to 270F hex (1 to 9999);
(0.1% to 999.9%, in units of
0.1%)
0001 to 1FFF hex (1 to 8191);
(9999 = Integral operation not
executed) (See note 1.)
0001 to 1FFF hex (1 to 8191);
(0000 = Derivative operation not
executed) (See note 1.)
0001 to 270F hex (1 to 9999);
(0.01 to 99.99 s, in units of
10 ms)
000 hex: = 0.65
Setting from 100 to 163 hex
means that the value of the right-
most two digits is set from =
0.00 to = 0.99. (See note 2.)
0: Output 0%
1: Output 50%
0: At start of PID instruction exe-
cution
1: At start of PID instruction exe-
cution and each sampling period
Section 3-18
Change with
ON input
condition
Allowed
Can be
changed with
input condition
ON if bit 1 of
C+5 is 1.
Not allowed
Allowed
775