Siemens SIMATIC S7-1200 - Page 326

Instructions
9.2 PID_3Step
PID control
326 Function Manual, 03/2017, A5E35300227-AC
Tag
Data type
Default
Description
CtrlParamsBackUp.Gain
REAL
1.0
Saved proportional gain
CtrlParamsBackUp.Ti REAL 20.0 Saved integration time in seconds
CtrlParamsBackUp.Td
REAL
0.0
Saved derivative action time in seconds
CtrlParamsBackUp.TdFiltRatio REAL 0.2 Saved derivative delay coefficient
CtrlParamsBack-
Up.PWeighting
REAL 1.0 Saved proportional action weighting
CtrlParamsBack-
Up.DWeighting
REAL 1.0 Saved derivative action weighting
CtrlParamsBackUp.Cycle
REAL
1.0
Saved sampling time of PID algorithm in seconds
CtrlParamsBack-
Up.InputDeadBand
REAL 0.0 Saved dead band width of the control deviation
PIDSelf-
Tune.SUT.CalculateParams
BOOL FALSE 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.
PIDSelfTune.SUT.TuneRule INT 1 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
PIDSelfTune.SUT.State INT 0 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