Panasonic FP-E Programming Manual page 1030

High−level Instructions
Operation of PID control
PID is a control method widely used in the instrumentation field involving feedback control of process
quantities such as temperature, pressure, flow, and fluid level.
1) Proportional operation
Proportional operation generates an output which is proportional to the input.
Setting signal SV
+
−
e
1
0
The amount of control is held constant.
An offset remains.
Proportional control grows stronger as Kp is increased.
2) Integral operation
Integral operation generates an output which is proportional to the integral time of the input.
Setting signal SV
+
−
mi=1/Tiedt
e
In combination with proportional operation or proportional−derivative operation, integral operation removes
the offset produced by these methods.
Integral operation grows stronger as the integral time (Ti) is shortened.
3 − 766
Phone: 800.894.0412 - Fax: 888.723.4773 - Web: www.clrwtr.com - Email: info@clrwtr.com
Offset e
Kp
Measurement
signal PV
MV 2
1
.5
t 0
Offset e
Integral
operation
Measurement
signal PV
mi
Output MV
Kp=2
Kp=1
Kp=.5
t
Output mi