Question Using Expressions:
Hello PI World! I’m trying to use expressions on Excel in conjunction with my PI Historian to filter data and identify spikes in a tag value. Specifically, there is a KW Import tag that spikes heavily but only for a second and then returns to a value very close to what it was just before the spike. My goal is to identify the spike and pull a report that shows its value and the timestamp.
It’s tricky because (1) there are multiple spikes within a 24 hour period, (2) each “spike” does not exceed a particular value ( i.e I can’t apply a filter at say 10,000 KW) and (2) the percentage of the “spike” isnt always the same.
I’d like to try to put as little stress on the Historian as possible – I can do it manually by scouring the trend report but it’s so manually intensive that it’s not cost effective for the customer if I tackle it this way. Is there an effective method to do this?
Any information would be greatly appreciated!