We want to replace our current totalizer tags with PI AF - if this is possible..
I have the challenge that i want to calculate an average of a tag/or attribute over a given period, lets say 30 min, but i want the timestamp to be set to the start of the period.
Using totalizer this is a no brainer - but i would rather avoid totalizers as we somtimes have delay in data and therefore we sometimes get wrong calculated totalizers.
What i so far have tried is to use PI AF (we are using version 2017 R2) - but we get no data into our database.
my expression is Tagavg('attribute','*-30m','*'), periodic triggered every 30 min and with the "output time stamp" set to relative to triggertime: *-30m. Here i'm thinking that i want the timestamp for the avg to be in the start of the period and not in the end... Am i thinking wrong ?
The system gives me in the preview results a nice table and trend - that shows me the data i want - and I can create the tags - but no data is written to the tag. The tag just is freezed at pt created.