How do I pass a tag to a UDT for us in an expression in 8.1

In Ignition 7.9 I could create a string parameter on a UDT and pass it the address of a tag then use that in an expression.


And the expression evaluates correctly.

This doesn't work in 8.1. It doesn't seam to evaluate the parameter in the same way.

Is there a different way in 8.1 to pass a tag to a UDT for use in an expression?

Your source is a string. If you want to read the value of it, you need to run it through the tag() function.

getBit(tag({Source}), {Offset})

It looks like you might want a derived tag though instead of an expression tag

That's what I needed. Just had to remove the braces {} and [~]. Thanks.

This is old code so predated derived tags. I'll look into it as I upgrade.