Siemens SIMATIC S7-1200 - Page 397

Instructions
9.3 PID_Temp
PID control
Function Manual, 03/2017, A5E35300227-AC
397
Tag
Data type
Default
Description
SubstituteOutput REAL 0.0 The substitute output value is used as PID output value as
long as the following conditions are met:
• One or more errors are pending in automatic mode for
which ActivateRecoverMode is in effect
• SetSubstituteOutput = TRUE
• ActivateRecoverMode = TRUE
The values at the outputs for heating and cooling resulting
from the substitute output value are the result of the con-
figured output scaling (structures Config.Output.Heat and
Config.Output.Cool).
For controllers with activated cooling output (Con-
fig.ActivateCooling = TRUE), define:
• a positive substitute output value to output the value at
the outputs for heating
• a negative substitute output value to output the value
at the outputs for cooling
The permitted value range is determined by the configura-
tion.
• Cooling output deactivated (Config.ActivateCooling =
FALSE):
Config.Output.Heat.PidUpperLimit ≥ SubstituteOutput
≥ Config.Output.Heat.PidLowerLimit
• Cooling output activated (Config.ActivateCooling =
TRUE):
Config.Output.Heat.PidUpperLimit ≥ SubstituteOutput
≥ Config.Output.Cool.PidLowerLimit
PidOutputSum REAL 0.0 PID output value
PidOutputSum displays the output value of the PID algo-
rithm. Depending on the operating mode, it is either calcu-
lated automatically or defined by the manual value or the
configured substitute output value.
The values at the outputs for heating and cooling resulting
from the PID output value are the result of the configured
output scaling (structures Config.Output.Heat and Con-
fig.Output.Cool).
The PidOutputSum is limited as defined in the configura-
tion.
• Cooling output deactivated (Config.ActivateCooling =
FALSE):
Config.Output.Heat.PidUpperLimit ≥ PidOutputSum ≥
Config.Output.Heat.PidLowerLimit
• Cooling output activated (ConfigActivateCooling =
TRUE):
Config.Output.Heat.PidUpperLimit ≥ PidOutputSum ≥
Config.Output.Cool.PidLowerLimit