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PE tags can only have one trigger tag.
You could make another PE tag that has logic to check the time and also check to see if the source tag has changed, and use that PE tag as the trigger for your original. It's another layer of complexity and another tag for each PE tag.
Your best bet is to use the analysis as you described.
One more doubt as mentioned in question
Like IsTrigger function in PI ACE, do we have similar one in PE or Analyses that shows which tag triggered the calculation?
Since PE can be triggered based on single tag only, I think it might not be available in PE. But what about analyses?
Not that I know of, but you would know which line of the analysis triggered it.
You could have a few lines in your analysis... assuming you are doing a calculation on tag XYZ:
- MIDNIGHT: if Hour('*')=0 and Minute('*')=0 then 1 else 0
- TAGCHANGE: if 'XYZ' <> TagVal('XYZ', '*-1m') then 1 else 0
- IF 'Midnight'=1 THEN calculation-at-midnight-involving-XYZ ELSE calculation-because-XYZ-changed
I hope that helps.
The analysis should be clock-scheduled (not event based) so you can detect when it is midnight.
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Steve just adding one more info here.
If we took MIDNIGHT as an attribute only, then point 3 is not triggering based on MIDNIGHT as an triggering input. But when I mapped this attribute to PI point, it started taking trigger event from MIDNIGHT also.
So currently in event-based trigger, attribute can't act as an triggering input .
True, I find the event-based trigger to only be useful in very simple analyses.