A Destination describes where and when event notifications should be sent for a particular recipient. It is the core data structure used inside Notification Class objects to define the distribution list for alarms and events.

Each destination combines a Recipient (which can be a device, a broadcast address, or an unicast address), a process identifier that the recipient will use to correlate the notification, a flag indicating whether confirmed or unconfirmed notifications should be used, the set of transitions (to-offnormal, to-fault, to-normal) that should trigger a notification, and a time window (valid days + from/to time) during which the subscription is active.

This structure allows very fine-grained control over alarm routing. For example, a critical high-priority alarm can be sent 24/7 to an operator workstation with confirmed notifications, while the same alarm can be sent only during business hours via unconfirmed notifications to a logging server. The time and day restrictions are evaluated by the Notification Class object itself when deciding whether to forward an event.

Examples (Doc Test)

iex> destination = %Destination{
...>   recipient: %Recipient{type: :device, device: %ObjectIdentifier{type: :device, instance: 123}, address: nil},
...>   process_identifier: 1,
...>   issue_confirmed_notifications: true,
...>   transitions: %EventTransitionBits{to_offnormal: true, to_fault: true, to_normal: true},
...>   valid_days: %DaysOfWeek{monday: true, tuesday: true, wednesday: true, thursday: true, friday: true, saturday: false, sunday: false},
...>   from_time: %BACnetTime{hour: 8, minute: 0, second: 0, hundredth: 0},
...>   to_time: %BACnetTime{hour: 18, minute: 0, second: 0, hundredth: 0}
...> }
iex> destination.process_identifier
1