This events are sent only in the Player so it's related to VoD and Live contents and related to the HeartBeat event. In case of VoD contents, two kinds of request are made to register events in the platform: AddEventPlayback (to register the analytics events) and the events for the PlaybackHeartBeat control.
In case of an OB has the [[PlaybackHeartBeat]] deactivated, and the device plays the Live content, the events for the Analytics won't be registered, because the Live player use the contents sent to the PlaybackHeartBeat to register the Events about player.
In general, this method is used by the player used on "PC Client" and "Go Web". But it can be used by other devices only in the player component.