Siemens SIMATIC S7-1200 Function Manual page 448

Instructions
9.3 PID_Temp
IntegralReset- Description
Mode
3 Pre-assign
The value of PIDCtrl.IOutputOld is automatically pre-assigned as if PidOutputSum = OverwriteI-
nitialOutputValue in the last cycle.
4 Like setpoint change (only for PID_Temp with version ≥ 1.1)
The value of PIDCtrl.IOutputOld is automatically pre-assigned so that a similar PID output value jump
results as for a PI controller in automatic mode in case of a setpoint change from the current process
value to the current setpoint.
Any control deviation will cause a jump of the PID output value. The PID output value jump and control
deviation have identical signs.
Example: If the process value value is smaller than the setpoint (positive control deviation), the PID
output value jumps to a positive value. This is independent of the configured weighting of the propor-
tional action and the control deviation.
If IntegralResetMode is assigned a value outside the valid value range, PID_Temp behaves
as with the pre-assignment of IntegralResetMode:
● PID_Temp up to V1.0: IntegralResetMode = 1
● PID_Temp as of V1.1: IntegralResetMode = 4
448
Function Manual, 03/2017, A5E35300227-AC
PID control