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Plotting values from Data Reference of type Formula

Question asked by lgferrao on Jan 16, 2018
Latest reply on Jan 25, 2018 by lgferrao

I'm going through an unexpected situation that I can not solve.

Here's my case:
I have two AF attributes configured in a Database.
The 'A' attribute with Value Type: Double and Data Reference: PI Point, is pointing to a PI Tag.

The 'B' attribute with Value Type: OffOn and Data Reference: Formula. This attribute uses the 'A' attribute to define whether the value will be Off or On. Formula: V = A; [if (V <2.5) then 1 else 0]

The attribute 'A' has readings in intervals of very small times, arriving to have 19 thousand values in an interval of 8 hours. Thus the 'B' attribute follows the same pattern of quantity values.

When performing a search of the historical values of attribute 'A' using PlotValues in a period of 8 hours, a small amount of values is always returned, which is normal behavior!

However, when using the PlotValues for attribute 'B', which is of Formula type, also in the period of 8 hours, all the values recorded are returned. That is, the 19 thousand values.
Apparently, when trying to use the PlotValues for the 'B' attribute, internally it is using the RecordedValues.

Is there a problem using PlotValues for attributes with Data Reference of type Formula?


I'm using AF SDK