PI Vision showing wrong value only in present time after recalculating

Question

This is a problem I run into pretty often and I still don't know what causes it. I have a tag I want to display in PI Vision, but sometimes after recalculating the analysis, even if the attribute shows the correct value, PI Vision shows a value of a previous timestamp. Sometimes this previous value, doesn't even exist anymore when I look for it in the Archive Editor so I don't understand where it comes from. The curious thing is that seems the analysis works well because if I go back any amount of time in PI Vision (e.g. 1 min in the past), it shows the correct value. It's like the correct values are "following" the present, but there's a wrong value stuck in the present all the time.

Thanks.

Christoph Rose · Accepted Answer

PI Vision has its own buffer for the current/snapshot value. Sometimes when you recalculate, PI Vision does not realize that the snapshot value changed and therefore won't reload/change the snapshot value.

If you restart the IIS, then it should reload the buffer and correct that mistake. It should also go away after some time or after a new snapshot value is written.

PI Vision showing wrong value only in present time after recalculating

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