The value for a tag displayed on vision is not present in system explorer or datalink. Where is this value coming from? Has anyone seen this?
Check the time context of your display. If it is not set to Now, PI Vision can display archive values and not the current value. PI Vision will surely not invent numbers.
It could of course display an interpolated value.. But first we need some more information on the exact situation we are looking at.
I think we all agree there is nothing wrong with PI Vision regarding the basic functions of displaying values.
I have reason to believe this is not an interpolated value. In Pi System Explorer, the interpolated value for the current day is much less that the ghost value I am seeing in Vision.w
Could be a classic case of un-synced Data Archive Collectives.
I wonder too if this could be it. Thanks, Vincent. I will kick this one up the chain.
Thanks for the reply Eugene. I've modulated the time window of the display and this occurs anytime for the Month of November. There should not be data in this monthly calculation tag for the month of November, because I have set the analysis to calculate the previous monthly total energy use at the beginning of each month and timestamp it for the previous month. On Nov. 1 the analysis ran and calculated the total energy use for all of October and timestamped it as Oct. 1. The October 1 data point is in the tag and the number is correct. However, on vision there is this ghost number for Nov. 1 and I am unsure where it is coming from. The Nov. 1 data point does not appear to be present in the in historian for these reasons: Using the compressed data function in Pi Datalink there is only data up to Oct. 1 in the tag. Using Pi System Explorer and viewing time series data for the tag there is also only data up to Oct. 1. So, the tag appears to have the correct data in it, but something Vision is pulling from is pulling this odd data point.
Please let us know the value is an ouput of analysis calculation or raw value. I have seen similar issue and did app pool recycle or iisreset it fixed. Also noticed that double clicking the value shows trend with correct value. Let us know if you are facing similar issue or other.
Lal - This is the output of an analysis and double clicking the trend still shows this errant value. I can see about resetting and such, but I believe we have already reset the systems. I'll have to double check with my colleague on this. Where I am at now, it seems most likely to me that this errant value could be from an old backfill from before I had the output timestamp override set. See my response to Eugene.
However, the value has been removed from the tag and it is not in historian. We've reset the Vision server and crawler and the value is still appearing on Vision. I have seen newly backfilled values take some time to appear in Vision, but nothing like this before.
Thanks for the help!
I had similar issue where analysis is writing to same tag from different analysis. Changed the tag and recalculated the same to fix the issue.
As Eugene said, you may need to verify the time frame of the display. Are you looking the same tag (of same data archive) in both PI Vision and PI SE? Is PI Data Archive Server has the new values for the tag which you are looking for?
Timeframe verified. Tags all identical. I believe data archive has the values. Thanks.
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