Errata exists for this version of the document.

The TimeAverage Aggregate defined in Table 17 uses Interpolated Bounding Values (see 3.1.8) to find the value of a point at the beginning and end of an interval. Starting at the starting bounding value a straight line is drawn between each value in the interval ending at the ending bounding value (see examples for illustrations). The area under the lines is divided by the length of the ProcessingInterval to yield the average. Note that this calculation always uses a sloped line between points; TimeAverage2 uses a stepped or sloped line depending on the value of the Stepped Property for the Variable.

If one or more Bad Values exist in the interval then they are omitted from the calculation and the StatusCode is set to Uncertain_DataSubNormal. Sloped lines are drawn between the Good values when calculating the area.

The time resolution used in this calculation is Server specific.

Table 17 – TimeAverage Aggregate summary

TimeAverage Aggregate Characteristics
Type	Calculated
Data Type	Double
Use Bounds	Interpolated
Timestamp	StartTime
Status Code Calculations
Calculation Method	Custom Good if no Bad values skipped and Good values are used, Uncertain if Bad values are skipped or if Uncertain values are used
Partial	Set Sometimes If an interval is not a complete interval
Calculated	Set Always
Interpolated	Not Set
Raw	Not Set
Multi Value	Not Set
Status Code Common Special Cases
Before Start of Data	Bad_NoData
After End of Data	Value extrapolated, Uncertain status
No Start Bound	Calculate Partial Interval
No End Bound	Extrapolate data, Uncertain status
Bound Bad	NA
Bound Uncertain	NA