Sample Pi Control - Omron SYSMAC CS Series Operation Manual

Examples of Applied Control Types
Note
Example
5-2-3

Sample PI Control

Noninteracting Control
Noninteracting control suppresses mutual action between processes, and
is the same as feedforward control. Influence caused by mutual action is
regarded as disturbance, and is controlled by noninteracting control to-
gether with feedforward control.
Function blocks used:
Processing by which the value after lead/delay operation is subtracted
from other MVs is enabled by the MV compensation function of advanced
PID.
Advanced PID
PV
Block Model 012
Output for MV compensation
MV compensation:
Subtraction
MV compensation:
Subtraction
Output for MV compensation
Advanced PID
PV
Block Model 012
3. Noninteracting control elements generally are one cause of lag.
Set Point
+
SP
PV
Set Point
SP
When processes with prolonged dead time or an ON/OFF measurement ana-
lyzer are taken as the control finite element, the next manipulated variable is
determined after the effect of having changed the manipulated variable has
sufficiently manifested itself.
PI control for time T1 is performed at every time T0, and resulting output is
held at a fixed value.
This is also called the "wait and see" method.
Advanced PID (Block Model 012)
Lead/Delay (Block Model 147)
MV
Lead/Delay Block
Model 147
Lead/Delay Block
Model 147
MV
+
PID control
Noninteracting
control
elements
Noninteracting
control
elements
PID control
Section 5-2
Control output
Process
characteristics
Control output
Process
characteristics
197