Omron CS1G/H-CPUxxH Instructions Manual page 707

Data Control Instructions
3-18-2 PID CONTROL WITH AUTOTUNING: PIDAT(191)
Purpose
Ladder Symbol
Variations
Applicable Program Areas
686
When P is narrowed
SV
Control by measured PID
• When there is broad hunting, or when operation is tied up by overshooting
and undershooting, it is probably because integral action is too strong.
The hunting will be reduced if the integral time is increased or the propor-
tional band is enlarged.
Control by measured PID
(when loose hunting occurs)
SV
Enlarge I or P.
• If the period is short and hunting occurs, it may be that the control system
response is quick and the derivative action is too strong. In that case, set
the derivative action lower.
Control by measured PID
(when hunting occurs in a short period)
SV
Lower D.
Executes PID control according to the specified parameters. The PID con-
stants can be autotuned.
This instruction is supported by the CS1-H, CJ1-H, CJ1M, and CS1D CPU
Units only.
Variations Executed Each Cycle for ON Condition
Executed Once for Upward Differentiation
Executed Once for Downward Differentiation Not supported.
Immediate Refreshing Specification
Block program areas
Not allowed OK
PIDAT(191)
S: Input word
S
C: First parameter word
C
D: Output word
D
Step program areas Subroutines
OK
Section 3-18
PIDAT(191)
Not supported.
Not supported.
Interrupt tasks
Not allowed