Configure value retrieval by time range

If you want the attribute value to be the result of a summary calculation over a time range, configure the value retrieval by time range.

1. Select an option from the By Time list. The default option is Automatic. For more information, see List of time retrieval options.

2. Select an option from the By Time Range list. The default option is End Time. For more information, see List of range retrieval options.

3. If the Calculation Basis list is enabled, select one of the following options.

   Note: If you select one of the time weighted options for a totalization, source units convert to a rate. Select a unit of time from the list next to the Source Units field.

   Option	Description
   Event Weighted	Evaluates values with equal weighting for each event. No interpolation is done. At least one event must be within the time range to perform a successful calculation. Two events are required for standard deviation. In handling events at the boundary of the calculation, PI AF uses the following rules: Events at both boundaries are used when there is only one calculation interval. Events at start time are included when multiple intervals exist and the intervals are in ascending time order. Events at the end time are included when multiple intervals exist and the intervals are in descending time order.
   Event Weighted Exclude Most Recent Event	Behaves the same as Event Weighted, 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 count at both intervals. With this option, events at the end time (most recent time) of an interval are not used in that interval.
   Event Weighted Exclude Earliest Event	Similar to the Event Weighted Exclude Most Recent Event option. Events at the start time (earliest time) of an interval are not used in that interval.
   Event Weighted Include Both Ends	Events at both ends of the interval boundaries are included in the event-weighted calculation.
   Time Weighted	Weights 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.
   Time Weighted Continuous	Applies weighting as in Time Weighted, but does all interpolation between values as if they represent continuous data (standard interpolation), regardless of the step attribute of the point.
   Time Weighted Discrete	Applies weighting as in Time Weighted but does interpolation between values as if they represent discrete, unrelated values (stair-step plot), regardless of the step attribute of the point.

4. In the Min percent good field, enter a value between 0 and 100. This is a percentage representing the minimal amount of time a value must be good before a summary value is returned. For time weighted calculations, the percentage is based on time. For event weighted calculations, the percent is based on event count.

5. Click OK.