Average and Step Values
The average of the raw samples is the interval, but there is special logic for time weighting and for computing the value at the start of the interval.
Averages are computed differently depending on the value of the Tag.StepValue property. If StepValuee=FALSE
then the average works as it always did in 2.0 and 3.0. A value at the start of the interval is determined via interpolation.
If StepValue=TRUE
then lab sampling, not interpolation, is used to determine the value at interval start time. This would more accurately reflect a value that steps or a value that uses collector compression and did not change for a long period of time.