Siemens SIMATIC S7-1200 Function Manual page 149

Derivative delay = derivative action time × derivative delay coefficient
● 0.0: Derivative action is effective for one cycle only and therefore almost not effective.
● 0.5: This value has proved useful in practice for controlled systems with one dominant
time constant.
● > 1.0: The greater the coefficient, the longer the effect of the derivative action is delayed.
Proportional action weighting
The proportional action may weaken with changes to the setpoint.
Values from 0.0 to 1.0 are applicable.
● 1.0: Proportional action for setpoint change is fully effective
● 0.0: Proportional action for setpoint change is not effective
The proportional action is always fully effective when the process value is changed.
Derivative action weighting
The derivative action may weaken with changes to the setpoint.
Values from 0.0 to 1.0 are applicable.
● 1.0: Derivative action is fully effective upon setpoint change
● 0.0: Derivative action is not effective upon setpoint change
The derivative action is always fully effective when the process value is changed.
PID algorithm sampling time
The controlled system needs a certain amount of time to respond to changes in the output
value. It is therefore not advisable to calculate the output value in every cycle. The sampling
time of the PID algorithm represents the time between two calculations of the output value. It
is calculated during tuning and rounded to a multiple of the PID_3Step sampling time. All
other functions of PID_3Step are executed at every call.
Dead band width
The deadband suppresses the noise component in the steady controller state. The dead
band width specifies the size of the dead band. The dead band is off if the dead band width
is 0.0.
If values not equal to 1.0 are configured for the proportional action weighting or the derivative
action weighting, setpoint changes even within the dead zone affect the output value.
Process value changes within the dead zone do not affect the output value, regardless of the
weighting.
PID control
Function Manual, 03/2017, A5E35300227-AC
Using PID_3Step
5.3 PID_3Step V1
149