Siemens SIMATIC S7-1200 Function Manual page 201

Synchronization of several fine tuning processes
If fine tuning is started from automatic mode with PIDSelfTune.TIR.RunIn = FALSE,
PID_Temp tries to reach the setpoint with PID controlling and the current PID parameters.
The actual tuning does not start until the setpoint is reached. The time required to reach the
setpoint can be different for the individual zones of a multi-zone control system.
If you want to carry out fine tuning for several zones simultaneously, PID_Temp offers the
possibility to synchronize these by waiting with the further tuning steps after the setpoint has
been reached.
Procedure
This ensures that all the controllers have reached their setpoint when the actual tuning steps
start. This reduces mutual influencing through thermal coupling between the zones during
tuning.
Proceed as follows for controllers for whose zones you want to carry out fine tuning
simultaneously:
1. Set PIDSelfTune.TIR.WaitForControlIn = TRUE for all controllers.
These controllers have to be in automatic mode with PIDSelfTune.TIR.RunIn = FALSE.
2. Specify the desired setpoints (Setpoint parameters) and start fine tuning for all controllers.
3. Wait until PIDSelfTune.TIR.ControlInReady = TRUE at all controllers.
4. Set PIDSelfTune.TIR.FinishControlIn = TRUE for all controllers.
All controllers then start the actual tuning simultaneously.
PID control
Function Manual, 03/2017, A5E35300227-AC
6.5 Multi-zone controlling with PID_Temp
Using PID_Temp
201