Create default time ranges for element attributes

You can create a default time range for element attributes. A default time range is a time range that PI AF uses when a client application provides a specific time, rather than a time range.

Note: Event frame and transfer attributes treat time ranges differently, as described in Understand time ranges for event frames and transfers.

1. In the PI Point Data Reference (or PI Point Array Data Reference) window, use the following value retrieval settings:

   1. From the By Time list, select Time Range.

   2. In the Relative Time field, type a PI relative time expression, as described in Understand relative time.

      Note: You can also use substitution parameters to read the relative time from the value of another attribute, as described in References to attribute values.

   PI AF creates a time range based on the time specified by the client application and the offset defined by the relative time.

Example

A totalization meter requires a time range in order to deliver a totalized value. If the client application sends a specific time, you want to create a one-hour time range that ends in the specified time. To do that, you would use these settings:

2. From the By Time list, select Time Range.

3. In the Relative Time field, type:

   -1h

4. From the By Time Range list, select Total.

Note: For a 24-hour totalizer you would set a relative time of -24h or -1d.