Siemens SIMATIC S7-1200 Function Manual page 98

Using PID_Compact
4.3 PID_Compact V1
Process value V1
PID_Compact will scale the value of the analog input to the physical quantity if you use the
analog input value directly.
You will need to write a program for processing if you wish first to process the analog input
value. The process value is, for example, not directly proportional to the value at the analog
input. The processed process value must be in floating point format.
Procedure
Proceed as follows to use the analog input value without processing:
1. Select the entry "Input_PER" in the drop-down list "Input".
2. Select "Instruction" as source.
3. Enter the address of the analog input.
Proceed as follows to use the processed process value in floating point format:
1. Select the entry "Input" in the drop-down list "Input".
2. Select "Instruction" as source.
3. Enter the name of the variable in which the processed process value is saved.
Output value V1
PID_Compact offers three output values. Your actuator will determine which output value
you use.
● Output_PER
The actuator is triggered via an analog output and controlled with a continuous signal,
e.g. 0...10V, 4...20mA.
● Output
The output value needs to be processed by the user program, for example because of
nonlinear actuator response.
● Output_PWM
The actuator is controlled via a digital output. Pulse width modulation creates minimum
ON and minimum OFF times.
98
Function Manual, 03/2017, A5E35300227-AC
PID control