The Aggregate functions supported for a PI Datasource are listed below. For information regarding other historians (for example, IP.21) or further details on the j5 OSIsoft PI Interface, please consult the relevant documentation.
|
Aggregate Function |
Description |
|---|---|
|
Total |
Total over time range |
|
Minimum |
Minimum for time range |
|
Maximum |
Maximum for time range |
|
StdDev |
The standard deviation over the time range |
|
Range |
The range of values over the time range |
|
Average |
The average value over the time range |
|
Mean |
The discrete average over the time range |
|
PStdDev |
The population standard deviation over the time range |
|
Count |
The sum of event count over the time range when calculation basis is eventweighted, sum of event time duration over the time range when calculation basis is timeweighted |
The Weighting functions (which are applied when calculating aggregates) supported for a PI Datasource are listed below:
|
Weighting Function |
Description |
|---|---|
|
TimeWeighted |
Weight the values in the calculation by the time over which they apply. Interpolation is based on the step attribute of the point. Interpolated events are generated at the boundaries if necessary |
|
EventWeighted |
Evaluate values with equal weighting for each event. No interpolation is done. There must be at least one event within the time range to perform a successful calculation. Two events are required for standard deviation |
|
TimeWeightedContinuous |
Apply weighting as in cbTimeWeighted, but do all interpolation between values as if they represent continuous data, (standard interpolation) regardless of the step attribute of the point |
|
TimeWeightedDiscrete |
Apply weighting as in cbTimeWeighted but interpolation between values is performed as if they represent discrete, unrelated values (stair step plot) regardless of the step attribute of the point |
|
EventWeightedExcludeMostRecentEvent |
The calculation behaves the same as cbEventWeighted, except in the handling of events at the boundary of summary intervals in a multiple intervals calculation. Use this option to prevent events at the intervals’ boundary from being double counted at both intervals. With this option, an event at the end time (most recent time) of an interval is not used in that interval |
|
EventWeightedExcludeEarliestEvent |
Similar to the option cbEventWeightedExcludeMostRecentEvent. With this option, an event at the start time (earliest time) of an interval is not used in that interval |
|
EventWeightedIncludeBothEnds |
With this option, events at both ends of the interval boundaries are included in the event weighted calculation |