QUESTION:  
How do you enter the scaling of the setpoint and actual values in the STEP 7 Micro/WIN V4 wizards for PID control loops?

ANSWER:  
The relation between the scaling of the setpoint and actual values in the PID control loop of the STEP 7 Micro/WIN wizards is illustrated in the following examples.

Example: 1
The measuring range of a sensor of 0 to 10V corresponds to 0 to 40 bar.

Input for scaling of the setpoint value:
Low limit value = 0.0
High limit value = 40.0

Fig. 1: Scaling of the setpoint value ( 52 KB )  

Input for scaling of the actual value:
Scaling = single-pole
Low limit value = 0
High limit value = 32000

Fig. 2: Scaling of the actual value ( 53 KB )  

Example: 2
The measuring range of a sensor of 4 to 20mA corresponds to 0 to 40 bar.

Input for scaling of the setpoint value:
Low limit value =  0.0
High limit value = 40.0

Input for scaling of the actual value:
Scaling = single-pole and 20% offset activated
Low limit value = 6400
High limit value = 32000

Example: 3
Sensor PT100 on the RTD module: 1°C corresponds to a value of 10.
Value range to be expected for this system (hot water): 0°C to a maximum of 120°C.

Input for scaling of the setpoint value:
Low limit value = 0.0
High limit value = 120.0

Input for scaling of the actual value:
Scaling =  single-pole
Low limit value = 0
High limit value = 1200

Example: 4
Sensor PT100 on the RTD module 1°C corresponds to a value of 10.
Value range to be expected for this system (baking oven): 0°C to a maximum of 370°C.

Input for scaling of the setpoint value:
Low limit value = 0.0
High limit value = 370.0

Input for scaling of the actual value:
Scaling = single-pole
Low limit value = 0
High limit value = 3700

Example: 5
Sensor PT100 on the RTD module 1°C corresponds to a value of 10.
Value range to be expected for this system (outside temperature): -30°C to a maximum of +60°C.

Input for scaling of the setpoint value:
Low limit value = -30.0
High limit value = +60.0

Input for scaling of the actual value:
Scaling =  double-pole
Low limit value = -300
High limit value =  +600

Conclusion:
The maximum setpoint values must match the analog values to be expected.