Analog Inputs and Outputs in an S7 PLC are represented in the PLC as a 16-bit integer. Over
the nominal span of the analog input or output, the value of this integer will range between -
27648 and +27648. However, it is easier to use the analog values if they are scaled to the
same units and ranges as the process being controlled. This applications tip describes
methods for scaling analog values to and from engineering units.