Hi Guys,

I will appreciate your support.

We are trying to build a expression able to show and saved data into PI Points. the expressiong that we built is If Day('*')=1 then TagTot('Feed',BOM('y'),BOM('t'))*24 else 0 and, it works but, only when this value is not saved into pi point.

If we try to save the expressions´ result into PI points, I found this mistake in some specific time stamps.

As you see, in the previous picture. We are trying to save monthly value at the beginning of the month. And, eventually, we are losing the right timestamp even when this expression works very good without save data into PI points.

I was wondering if this is a limitation from PI Expressions based on PI AF and, this is the time when we have to back to PI Totalizers based on PI Archive or, we forgot some additional attributes in the expression from PI AF.

Thank you very much for your suppport.

So two questions about this. First, how have you scheduled this analysis? Second, what do your results look like if you change the end time in the TagTot function to BOM('*'), as follows:

If Day('*') = 1 Then TagTot('Feed',BOM('y'),BOM('*')) * 24 Else 0

When you stated that

are you saying that if you preview the results then you see correct timestamping of your results, but this doesn't occur when you actually run a backfill/recalculation to an output point?