Rockwell Automation 1746-NI16V SLC 500 Analog Input Modules User Manual - Manual (Page 60)

Publication 1746-UM001A-US-P
5-12 Channel Configuration, Data, and Status
Scaling Examples
The following scaling examples show how to convert the channel
data word from the configured data type to “real” units. Real units are
the values being measured, such as temperature and pressure. To
perform the scaling, you must know the defined voltage or current
range for the channel’s input type. The lowest possible actual value
for an input type is ScaledMin, and the highest possible actual value is
ScaledMax. Refer to the Channel Data Word Value tables on page 5-9
and page 5-10 for the channel word signal ranges.
Formulas
Three formulas are used in all of the following examples. They are:
where:
and
NOTE
In all of the examples on pages 5-13 to 5-15, the zero
offset is the low range limit (InputMin).
Scaled Value Input Value Slope
× ( )
Offset + =
Slope
ScaledMax
·
ScaledMin –
( )
InputMax InputMin –
( )
------------------------------------------------------------------------------------- =
Offset ScaledMin InputMin Slope Ч ( )
– =