Siemens SIMATIC S7-1200 Function Manual page 124

Using PID_3Step
5.2 PID_3Step V2
Scaling V2 position feedback
Scaling position feedback
If you have configured the use of Feedback_PER in the basic settings, you will need to
convert the value of the analog input into %. The current configuration will be displayed in
the "Feedback" display.
Feedback_PER is scaled using a low and high value pair.
1. Enter the low pair of values in the "Low endstop" and "Low" input boxes.
2. Enter the high pair of values in the "High endstop" and "High" input boxes.
"Low endstop" must be less than "High endstop"; "Low" must be less than "High".
The valid values for "High endstop" and "Low endstop" depend upon:
● No Feedback, Feedback, Feedback_PER
● Output (analog), Output (digital)
Output
Output (digital)
Output (digital)
Output (digital)
Output (analog)
Output (analog)
Output (analog)
Output value limits V2
Limiting the output value
You can exceed or undershoot the output value limits during the transition time
measurement and with mode = 10. The output value is limited to these values in all other
modes.
Enter the absolute output value limits in the "Output value high limit" and "Output value low
limit" input boxes. The output value limits must be within "Low endstop" and "High endstop".
If no Feedback is available and Output (digital) is set, you cannot limit the output value.
Output_UP and Output_DN are then reset upon Actuator_H = TRUE or Actuator_L = TRUE.
If no endstop signals are available, Output_UP and Output_DN are reset after a travel time of
150% of the motor actuating time.
The default value of 150% can be adjusted using the tagConfig.VirtualActuatorLimit. As of
PID_3Step Version 2.3 the monitoring and limiting of the travel time can be deactivated with
Config.VirtualActuatorLimit = 0.0.
124
Feedback Low endstop
No Feedback Cannot be set (0.0%)
Feedback -100.0% or 0.0%
Feedback_PER -100.0% or 0.0%
No Feedback Cannot be set (0.0%)
Feedback -100.0% or 0.0%
Feedback_PER -100.0% or 0.0%
High endstop
Cannot be set (100.0%)
0.0% or +100.0%
0.0% or +100.0%
Cannot be set (100.0%)
0.0% or +100.0%
0.0% or +100.0%
Function Manual, 03/2017, A5E35300227-AC
PID control