Process Value Settings V2 - Siemens SIMATIC S7-1200 Function Manual

5.2.1.2

Process value settings V2

Process value scaling V2
If you have configured the use of Input_PER in the basic setting, you must convert the value
of the analog input to the physical quantity of the process value. The current configuration is
displayed in the Input_PER display.
Input_PER will be scaled using a low and high value pair if the process value is directly
proportional to the value of the analog input.
Procedure
To scale the process value, follow these steps:
1. Enter the low pair of values in the "Scaled low process value" and "Low" text boxs.
2. Enter the high pair of values in the "Scaled high process value" and "High" input boxes.
Default settings for the value pairs are stored in the hardware configuration. To use the value
pairs from the hardware configuration, follow these steps:
1. Select the PID_3Step instruction in the programming editor.
2. Interconnect Input_PER with an analog input in the basic settings.
3. Click the "Automatic setting" button in the process value settings.
The existing values will be overwritten with the values from the hardware configuration.
Process value limits V2
You must specify an appropriate absolute high limit and low limit for the process value as
limit values for your controlled system. As soon as the process value violates these limits, an
error occurs (ErrorBits = 0001h). Tuning is canceled when the process value limits are
violated. You can specify how PID_3Step responds to errors in automatic mode in the
actuator settings.
PID control
Function Manual, 03/2017, A5E35300227-AC
Using PID_3Step
5.2 PID_3Step V2
121