I have a UDT that I want to have an input parameter be an expression. The goal is to have a three tag expression from another tag provider be the input. Is this possible and is it bad practice to do it this way? I don't see an easy way to make the input an expression and I was curious how you have done it or would do it?
This tag dictates the steps it should take next, I was hoping to keep things in one place by having an input parameter of an expression and a proceed tag be true or false based on the expression.
It is possible with scripts. Receive tag events at your driving expression tag and write to the UDT instance parameters.
I've argued elsewhere in the forum that it is a bad practice. You are triggering tag reconfiguration based on live data. There are a few applications where it is difficult to avoid (redundant driver paths, for example), but every tag reconfig is a brief halt and opportunity for data loss/races.
Tags should not be reconfigured at runtime from live data. Full stop.
Thanks or the input, i was thinking it was no different that a standard expression tag with the exception that its a UDT. I was just trying to prevent from writing scripts between two tag providers, the thought was bring everything into one UDT and then I know my paths and what my values are regardless of the tag provider and tag path i might need to read.
I'll rethink the process and see what i come up with. Thanks!