Bounding value retrieval - how it works

The following illustration shows how bounding value retrieval returns a start bound point:

In this case, Historian retrieves the first point on or before the datetime requested in the query. The line (TC0) is the timestamp for which the start bound point is requested. P1 is returned because that is the start or first point for the query date time.

Historian can also use bounding value retrieval to return an end bound point, as in the following illustration:

In this case, Historian returns first point after the datetime requested in the query. TC0 is the timestamp for which the end bound point is requested and P3 is returned as the ending bound point because this is the first point after the query date time.