Siemens SIMATIC S7-1500T Function Manual

Instructions
9.2 PID_3Step
PID control
358 Function Manual, 03/2017, A5E35300227-AC
Tag
Data type
Default
Description
CycleTime.Value REAL 0.1 PID_3Step sampling time in seconds
CycleTime.Value is determined automatically and is usually equiv-
alent to the cycle time of the calling OB.
CtrlParamsBackUp.SetByUser BOOL FALSE Saved value of Retain.CtrlParams.SetByUser.
You can reload values from the CtrlParamsBackUp structure with
Config.LoadBackUp = TRUE.
CtrlParamsBackUp.Gain
REAL
1.0
Saved proportional gain
CtrlParamsBackUp.Ti
REAL
20.0
Saved integral action time
CtrlParamsBackUp.Td
REAL
0.0
Saved derivative action time
CtrlParamsBackUp.TdFiltRatio
REAL
0.0
Saved derivative delay coefficient
CtrlParamsBack-
Up.PWeighting
REAL 0.0 Saved proportional action weighting
CtrlParamsBack-
Up.DWeighting
REAL 0.0 Saved derivative action weighting
CtrlParamsBackUp.Cycle
REAL
1.0
Saved sampling time of PID algorithm
CtrlParamsBack-
Up.InputDeadBand
REAL 0.0 Saved dead zone width of the control deviation
PIDSelfTune.SUT.Calculate-
SUTParams
BOOL FALSE The properties of the controlled system are saved during tuning. If
CalculateSUTParams = TRUE, the PID parameters are recalculat-
ed on the basis of these properties. The PID parameters are calcu-
lated using the method set in TuneRuleSUT. CalculateSUTParams
is set to FALSE following calculation.
PIDSelfTune.SUT.TuneRule-
SUT
INT 1 Methods used to calculate parameters during pretuning:
• TuneRuleSUT = 0: PID fast I
• TuneRuleSUT = 1: PID slow I
• TuneRuleSUT = 2: Chien, Hrones and Reswick PID
• TuneRuleSUT = 3: Chien, Hrones, Reswick PI
• TuneRuleSUT = 4: PID fast II
• TuneRuleSUT = 5: PID slow II
PIDSelfTune.SUT.State
INT
0
The SUT.State tag indicates the current phase of pretuning:
PIDSelfTune.TIR.RunIn BOOL FALSE
• RunIn = FALSE
Pretuning is started when fine tuning is started from inactive or
manual mode.
If fine tuning is started from automatic mode, the system uses
the existing PID parameters to control to the setpoint.
Only then will fine tuning start. If pretuning is not possible,
PID_3Step switches to "Inactive" mode.
• RunIn = TRUE
The pretuning is skipped. PID_3Step attempts to reach the set-
point with the minimum or maximum output value. This can
produce increased overshoot. Only then will fine tuning start.
RunIn is set to FALSE after fine tuning.

Siemens SIMATIC S7-1500T Specifications

General

Brand	Siemens
Model	SIMATIC S7-1500T
Category	Controller
Language	English