Siemens SIMATIC S7-1200 - Page 307

Instructions
9.2 PID_3Step
PID control
Function Manual, 03/2017, A5E35300227-AC
307
PID algorithm
PID_3Step is a PIDT1 controller with anti-windup and weighting of the proportional and
derivative actions. The PID algorithm operates according to the following equation:
Symbol
Description
Δy
Output value of the PID algorithm
K
p
Proportional gain
s
Laplace operator
b
Proportional action weighting
w
Setpoint
x
Process value
T
I
Integral action time
T
D
Derivative action time
a
Derivative delay coefficient (derivative delay T1 = a × T
D
)
c
Derivative action weighting