**Siemens PLC Analog Input Scaling**
The following variables are pertinent to the scaling formula:
Ov = scaled output value
Iv = analog input value
Osh = high limit of the scale for the scaled output value
Osl = low limit of the scale for the scaled output value
Ish = high limit of the scale for the analog input value
Isl = low limit of the scale for the analog input value

The scaling scheme can be diagrammed as follows: The following formula for calculating the scaled value can be derived from the diagram: Ov = [(Osh – Osl) * (Iv -Isl) / (Ish – Isl)] + Osl Which can be rewritten as: Ov = [(Osh -Osl)/(lsh-lsl)/(lsh -lsl)] + Osl