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PI AF analysis not writing values back to attribute

Question asked by Cheerion Champion on Sep 15, 2017
Latest reply on Sep 15, 2017 by gmichaud-verreault

Dear all,


I'm pretty new to PI AF as I only started with it 4 months ago. In the meanwhile, I was lucky to spend quite some time on it but last week I noticed something I could not explain immediately. An ideal moment to post something on the forum...


On the image underneath, you will see an analysis I created to summarize quarter-hourly data into daily values. 5 of the 7 calculations are mapped to attributes which are set as pi point reference.

  • The first 2 calculations ('ACEventCount' and 'APEventCount') are there to count the events in the timeframe defined.
  • Calculation 3 and 4 ('ACTotal' and 'APTotal') are summarizing the quarter-hourly values into daily data (TagMean * eventcount).
  • Calculation 5 and 6 ('ACTotalFinalNet' and 'APTotalFinalNet') are there because I want to substract them from each other in calculation 7 and therefor I couldn't use calculation 3 and 4 because I need a 0 instead of NoOutput() to perform the calculation correctly.
  • Calculation 7 ('FinalNetTotal') is - as mentioned above - there to substract 2 earlier calculated variables and write the value into an attribute.


As you can see, all calculations are executed without errors.


For your informatoin, the attributes 'E4U_AC_active' and 'E4U_AP_active' are booleans. They are both set to 'True' in this example. I only use them because not every instance of the template will have both active.




The image underneath is a screenshot of the attribute screen. As you can see, 4 out of 5 mapped signals (colored green) are writing something back to the PI-tag but calculation 7 ('FinalNetTotal' - colored red) is writing nothing back as 'Pt created' as signal state is still visible.



Does anybody know why 4 out of 5 calculations perform as expected and one isn't?


Thanks in advance for your feedback.