AnsweredAssumed Answered

How to Cleanly Run Analysis with Potential Non Existent Points

Question asked by ColonialPipeline on Feb 26, 2019

Hello all. I am trying to run an analysis in a template which outputs a value to an attribute based on whether certain PI tags exist as shown below.




if not(BadVal(TagName('Flow2'))) Then ('Flow1'*1000/'Flow2') Else (if not(BadVal(TagName('Flow3'))) Then (Flow1'*1000/'Flow3') Else NoOutput())



Flow1 is always tied to an existing PI tag

Flow2 and Flow 3 may or may not be tied to an existing PI tag

The analysis is event triggered on Flow1


This is working but has three downsides I was hoping to avoid.

1) All the attributes must exist and not be excluded for the analysis to run. This means I must present these attributes to the users even when I know they are tied to a non-existent PI tag.

2) The analysis shows a warning saying "Failed to sign up some input(s) for receiving updates" if one of the attributes is tied to an attribute with a non existent PI tag. I can live with this since it is not user facing.

3) I can not perform a backfill due to any missing PI tag


Is there a better way to do something like this that won't have these downsides.