Scaling to engineering units in input devices

Channel data values in the input tag may be in engineering units such as Bar, Degrees Celsius, Kg/minute or percentage. To configure the relationship between the physical signal in volts or mA and engineering units, set the

Low

and

High Signal

and the

Low

and

High Engineering

values.

For example, a temperature transmitter on channel 3 which produces 4 mA current at -180 degrees C and 20 mA of current at 750 degrees C, and you are using Degrees C in your control program, configure the values as in this table.

If you are using HART field devices, we recommend setting

High Engineering

and

Low Engineering

to the field device’s

Upper Range Value

and

Lower Range Value

so that the field device uses the same engineering units as the 1756-IF8H. If online, these values display in

HART Device Information

view.