Siemens SIMATIC S7 System Manual page 593

Loop monitoring
After you have completed the auto-tune sequence and have transferred the suggested
tuning parameters to the CPU, you can use the control panel to monitor your loop's response
to a step change in the setpoint.
In the figure below, the loop responds to a setpoint change with the original tuning
parameters (before running auto-tune). Notice the overshoot and the long, damped ringing
behavior of the process using the original tuning parameters.
The loop responds to the same setpoint change after applying the values determined by the
auto-tune process using the selection for a fast response. Notice that for this process there is
no overshoot, but there is just a little bit of ringing.
S7-200 SMART
System Manual, V2.3, 07/2017, A5E03822230-AF
PID loops and tuning
11.7 PID Tune control panel
593