Siemens SIMATIC S7-1200 Function Manual page 398

Instructions
9.3 PID_Temp
Tag
PidOutputOffsetHeat
PidOutputOffsetCool
SubstituteSetpointOn
SubstituteSetpoint
DisableCooling
398
Data type Default
REAL 0.0
REAL 0.0
BOOL FALSE
REAL 0.0
BOOL FALSE
Description
Offset of the PID output value heating
PidOutputOffsetHeat is added to the value that results
from PidOutputSum for the heating branch. Enter a posi-
tive value for PidOutputOffsetHeat to receive a positive
offset at the outputs for heating.
The resulting values at the outputs for heating are the
result of the configured output scaling (Config.Output.Heat
structure).
This offset can be used for actuators which need a fixed
minimum value, for example, fans with minimum speed.
Offset of the PID output value cooling
PidOutputOffsetCool is added to the value that results
from PidOutputSum for the cooling branch. Enter a nega-
tive value for PidOutputOffsetCool to receive a positive
offset at the outputs for cooling.
The resulting values at the outputs for cooling are the
result of the configured output scaling ( Con-
fig.Output.Cool structure).
This offset can be used for actuators which need a fixed
minimum value, for example, fans with minimum speed.
Activates the substitute setpoint as controller setpoint.
FALSE = the Setpoint parameter is used.
•
TRUE = the SubstituteSetpoint parameter is used as
•
setpoint
SubstituteSetpointOn can be used to specify the setpoint
of a slave controller in a cascade directly without having to
change the user program.
Substitute setpoint
If SubstituteSetpointOn = TRUE, the SubstituteSetpoint
parameter is used as setpoint.
Valid range of values:
Config.SetpointUpperLimit ≥ SubstituteSet-
point ≥ Config.SetpointLowerLimit, Config.InputUpperLimit
≥ SubstituteSetpoint ≥ Config.InputLowerLimit
DisableCooling = TRUE deactivates the cooling branch for
heating/cooling controllers (Config.ActivateCooling =
TRUE) in Automatic mode by setting PidOutputSum to 0.0
as low limit.
PidOutputOffsetCool and the output scaling for the cooling
outputs remain active.
DisableCooling can be used for tuning of multi-zone appli-
cations to temporarily deactivate the cooling branch as
long as all controllers have not completed their tuning yet.
This parameter is set/reset by the user manually and is not
automatically reset by the PID_Temp instruction.
Function Manual, 03/2017, A5E35300227-AC
PID control