Siemens Simatic S7-1500 - Page 424

Instructions
9.3 PID_Temp
PID control
424 Function Manual, 03/2017, A5E35300227-AC
Tag
Data type
Default
Description
PIDCtrl.PIDInit BOOL FALSE PIDCtrl.PIDInit is available as of PID_Temp version 1.1.
If PIDCtrl.PIDInit = TRUE in "Automatic mode", the integral
action PIDCtrl.IOutputOld is pre-assigned automatically as
if PidOutputSum = OverwriteInitialOutputValue in the pre-
vious cycle. This can be used for a Override control with
PID_Temp (Page 202).
Retain.CtrlParams.SetByUser BOOL FALSE If the PID parameters are entered manually in the configu-
ration editor, SetByUser = TRUE.
This parameter is used for display in the editors and does
not influence the control algorithm.
SetByUser is retentive.
Retain.CtrlParams.Heat.Gain REAL 1.0 Active proportional gain for heating
Heat.Gain is retentive.
Heat.Gain ≥ 0.0
Retain..CtrlParams.Heat.Ti REAL 20.0 Active integral action time for heating in seconds
The integral action for heating is switched off with
Heat.CtrlParams.Ti = 0.0.
Heat.Ti is retentive.
100000.0 ≥ Heat.Ti ≥ 0.0
Retain.CtrlParams.Heat.Td REAL 0.0 Active derivative action time for heating in seconds
The derivative action for heating is switched off with
Heat.CtrlParams.Td = 0.0.
Heat.Td is retentive.
100000.0 ≥ Heat.Td ≥ 0.0
Retain.CtrlParams.Heat
.TdFiltRatio
REAL 0.2 Active derivative delay coefficient for heating
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 con-
trolled systems with
one
dominant time constant.
• > 1.0: The greater the coefficient, the longer the effect
of the derivative action is delayed.
Heat.TdFiltRatio is retentive.
Heat.TdFiltRatio ≥ 0.0