Hello all -
We have an interesting problem. We are historizing a tag EVERY minute from PI from start of the shift (at 7:00 AM) till. current time in the shift
To explain -
at 7:01 we run a history query from 7:00 till 7:01 , store the value
at 7:02 we run a history query from 7:01 till 7:02, store the value
at 7:03 we run a history query from 7:02 till 7:03, store the value
and so forth....
To cross-verify, these values, I ran a SINGLE history query from 7:00 to 7:03 at a later time (say at 8:00).
I found that sometimes the values from both the queries do not correspond for the same date/time stamp?? This was especially true if a downtime occured at say in the middle say 7:02.
Have anyone else observed similar results when querying a tag from PI.
Any idea why this is happening? Thanks for any help. I could provide more details if needed.