-- The Tracked Object Datasources  are not re-evaluated when the user does a manual refresh.

-- Dashboard Viewer

-- The Tracked Object datasources are refreshed only on event arrival.
They are not re-evaluated when the user does a manual refresh: when an event arrives for the tracked object on which the datasource is defined and if the event meets the criteria in the definition of the datasource then the datasource is evaluated.

A Tracked object datasource always returns only one event following the 2 rules described below:
   1. if no rewind time is defined, then the Tracked Object datasource returns the last event received
   2. if a rewind time is defined, then the tracking object datasource returns the last event received before the delay represented by the rewind time.