Hi. I'm trying to set up a WEST controller but I'm not sure what the "input span" is.

Could anyone explain how I determine this value (in simple terms!)

 

It wants to know what the span of the device you are connecting
e.g.
Pressure transmitter 50 - 100 psi
temperature transmitter 0 - 100°C

Roy

 

Depending on context, input span is either
- the range of input, from lower to upper
- the top end of value of the input

range: a 4-20mA signal (usually) has corresponding engineering units,
where
4ma = some 'zero' value
20mA = some 'span' value
The difference between span and zero is the input range or input span.

If input is J thermocouple, range -200 to 1600°F, then zero = -200°F, then span = 1600°F

The input range or input span could be considered 1800°F, the range of -200 to 1600.

Top end value:
Whatever the top end of the input scale is.
for the J T/C 1600°F is the "span value", as old timers call it when they calibrate.

 

Thank you very much for your help.

Much appreciated.
John D.