Siemens SIMATIC S7-1200 Function Manual page 166

Using PID_Temp
6.2 Configuring PID_Temp
If one or more of the following errors occur in automatic mode, PID_Temp switches to
"Substitute output value with error monitoring" mode and outputs the last valid PID output
value (PidOutputSum):
– 0000002h: Invalid value at Input_PER parameter.
– 0000200h: Invalid value at Input parameter.
– 0000400h: Calculation of output value failed.
– 0001000h: Invalid value at Setpoint or SubstituteSetpoint parameter.
The values at the outputs for heating and cooling resulting from the PID output value are
produced by the configured output scaling.
As soon as the errors are no longer pending, PID_Temp switches back to automatic
mode.
If an error occurs during manual mode, PID_Temp remains in manual mode and
continues to use the manual value as the PID output value.
If the manual value is invalid, the configured substitute output value is used.
If the manual value and substitute output value are invalid, the low limit of the PID output
value for heating (Config.Output.Heat.PidLowerLimit) is used.
If the following error occurs during pretuning or fine tuning, PID_Temp remains in active
mode:
– 0000020h: Pretuning is not permitted during fine tuning.
When any other error occurs, PID_Temp cancels the tuning and switches to the mode
from which tuning was started.
● Substitute output value while error is pending
PID_Temp behaves as described at "Current value while error is pending", but outputs
the configured substitute output value (SubstituteOutput) as a PID output value
(PidOutputSum) in "Substitute output value with error monitoring" operating mode.
The values at the outputs for heating and cooling resulting from the PID output value are
produced by the configured output scaling.
In the case of controllers with activated cooling output (Config.ActivateCooling = TRUE),
enter:
– 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.
If the following error occurs, PID_Temp stays in "Substitute output value with error
monitoring" mode and outputs the low limit of the PID output value for heating
(Config.Output.Heat.PidLowerLimit):
– 0020000h: Invalid value at SubstituteOutput tag.
166
Function Manual, 03/2017, A5E35300227-AC
PID control