Siemens Simatic S7-1500 - Page 261

Instructions
9.1 PID_Compact
PID control
Function Manual, 03/2017, A5E35300227-AC
261
Tag
Data type
Default
Description
Retain.CtrlParams.Ti REAL 20.0
• CtrlParams.Ti > 0.0: Active integral action time
• CtrlParams.Ti = 0.0: Integral action is deactivated
Ti is retentive.
Retain.CtrlParams.Td REAL 0.0
• CtrlParams.Td > 0.0: Active derivative action time
• CtrlParams.Td = 0.0: Derivative action is deac-
tivated
Td is retentive.
Retain.CtrlParams.TdFiltRatio REAL 0.2 Active derivative delay coefficient
The derivative delay coefficient delays the effect of the
derivative action.
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 con-
stant.
• > 1.0: The greater the coefficient, the longer the
effect of the derivative action is delayed.
TdFiltRatio is retentive.
Retain.CtrlParams.PWeighting REAL 1.0 Active 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.
PWeighting is retentive.