Siemens SIMATIC S7-1200 Function Manual page 326

Instructions
9.2 PID_3Step
Tag
CtrlParamsBackUp.Gain
CtrlParamsBackUp.Ti
CtrlParamsBackUp.Td
CtrlParamsBackUp.TdFiltRatio REAL
CtrlParamsBack-
Up.PWeighting
CtrlParamsBack-
Up.DWeighting
CtrlParamsBackUp.Cycle
CtrlParamsBack-
Up.InputDeadBand
PIDSelf-
Tune.SUT.CalculateParams
PIDSelfTune.SUT.TuneRule
PIDSelfTune.SUT.State
326
Data type Default
REAL 1.0
REAL 20.0
REAL 0.0
0.2
REAL 1.0
REAL 1.0
REAL 1.0
REAL 0.0
BOOL FALSE
INT 1
INT 0
Description
Saved proportional gain
Saved integration time in seconds
Saved derivative action time in seconds
Saved derivative delay coefficient
Saved proportional action weighting
Saved derivative action weighting
Saved sampling time of PID algorithm in seconds
Saved dead band width of the control deviation
The properties of the controlled system are saved during
tuning. If CalculateParams = TRUE, the PID parameters are
recalculated on the basis of these properties. The PID pa-
rameters are calculated using the method set in TuneRule.
CalculateParams is set to FALSE following calculation.
Methods used to calculate parameters during pretuning:
SUT.TuneRule = 0: PID fast I
•
SUT.TuneRule = 1: PID slow I
•
SUT.TuneRule = 2: Chien, Hrones and Reswick PID
•
SUT.TuneRule = 3: Chien, Hrones, Reswick PI
•
SUT.TuneRule = 4: PID fast II
•
SUT.TuneRule = 5: PID slow II
•
The SUT.State tag indicates the current phase of pretuning:
State = 0: Initialize pretuning
•
State = 50: Determine start position without position
•
feedback
State = 100: Calculate the standard deviation
•
State = 200: Find the point of inflection
•
State = 300: Determine the rise time
•
State = 9900: Pretuning successful
•
State = 1: Pretuning not successful
•
Function Manual, 03/2017, A5E35300227-AC
PID control