I am using excel to extract data from PI and I don't find the appropriate PI function to extract 2 values. I have a time interval and I want to extract the first and the last values saved by PI in that interval.
I tried to use PIArcVal function with "next only" and the horodate of the beginning of the time interval to extract the first value, but as I can't constraint the extraction to the time interval only by defining the end of the interval, so I extract a value which is not inside the time interval.
Same problem to extract the last value using "previous only" and the horodate of the end of the time interval.
Is there a way to modify the function to include two horodates to constraint the extraction ?