V1 Final Controlling Element Setting - Siemens SIMATIC S7-1200 Function Manual

Using PID_3Step
5.3 PID_3Step V1
5.3.1.3

V1 final controlling element setting

Actuator-specific times
Configure the motor transition time and the minimum ON and OFF times to prevent damage
to the actuator. You can find the specifications in the actuator data sheet.
The motor transition time is the time in seconds the motor requires to move the actuator from
the closed to the opened state. The maximum time that the actuator is moved in one
direction is 110% of the motor transition time. You can measure the motor transition time
during commissioning.
The motor transition time is taken into consideration in the calculation of the analog output
value as well as in the calculation of the digital output values. It is mainly required for correct
operation during auto-tuning and the anti-windup behavior.
If no relevant motor transition time is in effect in your process (e.g. with solenoid valves), so
that the output value has a direct and full effect on the process, use PID_Compact instead.
If you are using "Output_UP" or "Output_DN", you can reduce the switching frequency with
the minimum on and minimum OFF time.
The on or off times calculated are totaled in automatic mode and only become effective
when the sum is greater than or equal to the minimum on or OFF time.
A rising edge at Manual_UP or Manual_DN in manual mode will operate the actuator for at
least the minimum on or OFF time.
If you have selected the analog output value Output_PER, the minimum ON time and the
minimum OFF time are not evaluated and cannot be changed.
Reaction to error
PID_3Step is preset so that the controller stays active in most cases in the event of an error.
If errors occur frequently in controller mode, this default reaction has a negative effect on the
control response. In this case, check the Errorbits parameter and eliminate the cause of the
error.
PID_3Step generates a programmable output value in response to an error:
● Current value
PID_3Step is switched off and no longer modifies the actuator position.
● Current value for error while error is pending
The controller functions of PID_3Step are switched off and the position of the actuator is
no longer changed.
If the following errors occur in automatic mode, PID_3Step returns to automatic mode as
soon as the errors are no longer pending.
– 0002h: Invalid value at Input_PER parameter.
– 0200h: Invalid value at Input parameter.
– 0800h: Sampling time error
– 1000h: Invalid value at Setpoint parameter.
– 2000h: Invalid value at Feedback_PER parameter.
– 4000h: Invalid value at Feedback parameter.
– 8000h: Error during digital position feedback.
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Function Manual, 03/2017, A5E35300227-AC
PID control