Good morning Riddhi,

Thanks for your question.

With distributed analog I/O modules that are not part of the 1756 line, like Compact (1769) Flex (1794) and Point (1734) I/O analog modules, you typically look up the analog module's “fixed” min and max range in the product's user manual.

For instance, for a Compact I/O 1769-IF4 analog module, 4-20ma equals 6241 to 31206 as found on page 3-11 of publication 1769-um002: https://literature.rockwellautomation.com/idc/groups/literature/documents/um/1769-um002_-en-p.pdf

That said, with 1756 Analog Modules you can actually do the analog scaling right on board the module itself, which allows you to make the range whatever you want.

So in this lesson, at around 3:47 in the video, I set my 1756 analog module's range to emulate what an older module might output so we can then scale that value to our engineering units using the SCP instruction.

But in practice, the SCP instruction would typically be used with Compact, Flex, and Point I/O analog modules that don't have the onboard scaling feature that the 1756 analog modules have.

Hope this helps,

Shawn Tierney,
Instructor, The Automation School