The hardware-interface PD_16494-06 - Power_state_notification_interface is a subcomponent. You can add it to all the components where you want to handle changes in the power state.
When the power state changes, you get a notification. Further, you get the current power state in the local variable “events”. One of these states is “External_power_lost”. In other words, you get this event, when you lose the main supply, and your device runs on a battery.
See the small basic example below.
Nb. Once you add the interface you can only locate your component in devices with batteries (i.e. PD 688, PD 803, and PD 802).