Pid Parameters - Siemens SIMATIC S7-1200 Function Manual
Pid control
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Also See for SIMATIC S7-1200:
- Manual (364 pages) ,
- System manual (338 pages) ,
- Reference manual (89 pages)
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Using PID_Temp
6.2 Configuring PID_Temp
6.2.4.3
PID parameters
The PID parameters are displayed in the "PID Parameters" configuration window.
If cooling is activated in the basic settings and PID parameter switching is selected as the
method for heating/cooling in the output settings, two parameter sets are available: One for
heating and one for cooling.
In this case, the PID algorithm decides on the basis of the calculated output value and the
control deviation whether the PID parameters for heating or cooling are used.
If cooling is deactivated or the cooling factor is selected as the method for heating/cooling,
the parameter set for heating is always used.
During tuning, the PID parameters are adapted to the controlled system with the exception of
the dead zone width that has to be configured manually.
PID_Temp is a PIDT1 controller with anti-windup and weighting of the proportional and
derivative actions.
The PID algorithm operates according to the following equation (control zone and dead zone
deactivated):
Symbol
Description
y
Output value of the PID algorithm
K
Proportional gain
p
s
Laplace operator
b
Proportional action weighting
w
Setpoint
x
Process value
T
Integral action time
I
T
Derivative action time
D
a
Coefficient for derivative-action delay
(Derivative delay T1 = a × T
c
Derivative action weighting
DeadZone
Dead zone width
ControlZone
Control zone width
174
Associated parameters of the PID_Temp instruc-
tion
-
Retain.CtrlParams.Heat.Gain
Retain.CtrlParams.Cool.Gain
CoolFactor
-
Retain.CtrlParams.Heat.PWeighting
Retain.CtrlParams.Cool.PWeighting
CurrentSetpoint
ScaledInput
Retain.CtrlParams.Heat.Ti
Retain.CtrlParams.Cool.Ti
Retain.CtrlParams.Heat.Td
Retain.CtrlParams.Cool.Td
Retain.CtrlParams.Heat.TdFiltRatio
)
Retain.CtrlParams.Cool.TdFiltRatio
D
Retain.CtrlParams.Heat.DWeighting
Retain.CtrlParams.Cool.DWeighting
Retain.CtrlParams.Heat.DeadZone
Retain.CtrlParams.Cool.DeadZone
Retain.CtrlParams.Heat.ControlZone
Retain.CtrlParams.Cool.ControlZone
Function Manual, 03/2017, A5E35300227-AC
PID control
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