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The "True for" time of event frame generation analyses should not consider the extrapolation after the snapshot event

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Originally posted on UserVoice

PI assumes that the value of a PI Point from its snapshot event up to now is equal to the snapshot value. This extrapolation is not necessarily a good representation of what the interpolation will look like when new data arrives.

The extrapolation can cause event frames to generate prematurely, and by the time the user compares the trigger data to the event frame, new data will have arrived, which turns the extrapolation into interpolation, and it will look like the event frames should not have generated.

This problem gets worse the more any of the following conditions hold true:
• event frame generation analysis has a short "True for" time
• trigger signal is noisy or has occasional random spikes and dips
• trigger signal's timestamp represents the time that the signal was generated and it takes long time for the signal to reach the PI Data Archive (could be due to infrequent scanning or delays in signal transmission)

Since the extrapolation does not represent real data, it should not count towards the "True for" time of event frame generation analyses.


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