Subscribe to alarms and events from a client

Clients indicate interest in alarms and events by subscribing to an Area. When subscribing to an Area, the subscription is actually to all notification distributors within that Area.

For example, if an Area contains sub-Areas, those sub-Areas are subscribed to. If WinPlatforms, AppEngines or Device Integration objects belong to an Area, those objects are also directly subscribed to.

When a notification distributor receives an alarm and event subscription from a client, the notification distributor provides the client with the following:

• A list of all current alarm conditions, including unacknowledged return-to-normal conditions.

• An alarm condition state change. A state change includes transitions into or out of alarm (return to normal) and change in acknowledged flag.

• An event occurrence.

Alarm and event subscription requests do not include filters, for example, only show alarms greater than a specific priority value. All alarm and event messages received by the notification distributor are sent to all subscribed clients. Filtering is provided as a display option by clients.