Add to Alarm Cache

Users can add a device into alarm cache via the Project Explorer within the BACnet Provider in the Workbench. The intended device to be added to the alarm cache first has to be in the address space (has to be scanned).

Right-click on the device you wish to add into alarm cache, then click on Add to Alarm Cache, as shown below.

Adding a Device to Alarm Cache Within the BACnet Provider in the Workbench

-OR-

Select the device you wish to add to the alarm cache, then click on the Add to Alarm Cache button, shown below, in the Tools section of the Home ribbon in the Workbench.

Add to Alarm Cache Button

Once added to the Alarm Cache, a confirmation window will appear, as shown below.

Confirmation of Addition to the Alarm Cache

Users also have the option to remove added devices from the alarm cache. Users can also set a default as to whether or not discovered devices are automatically added to alarm cache.

The user can then subscribe a client (e.g. AlarmWorX64 Viewer) to the BACnet root, device or to specific notification class(es).

Example of Subscribing to a Notification Class

Remove from Alarm Cache

Once a Device has been added to the Alarm Cache, it can also be removed by similar steps.

Select the device that need to be removed within the Project Explorer, then click on Remove from Alarm Cache in the pulldown menu, as shown below.

Remove from Alarm Cache in the Project Explorer

-OR-

Select the Device to remove from the Alarm Cache, then click on the Remove from Alarm Cache button, shown below, in the Tools section of the Home ribbon in the Workbench.

Remove from Alarm Cache Button

Once removed from the Alarm Cache, a confirmation window will appear, as shown below.

Confirmation of Removal from the Alarm Cache

Runtime

When the device is added into the alarm cache, the BACnet Runtime subscribes to all notification classes in the device. The initial state of the alarms is read after successful subscription via GetAlarmSummary, GetEnrolmentSummary or GetEventInformation services. Notification classes send the event notifications into the BACnet Runtime when there is any alarm/event. Notifications are then sent to the subscribed clients (e.g. AlarmWorX64 Viewer instances).

When the device is removed from the alarm cache, the BACnet Runtime unsubscribes from all notification classes in the device and destroys the cached information for this device.

Time Stamps

BaseConditionType.ActiveTime

Changes when the alarm transition goes to active

BaseEventType.Time

Changes when there is any change in the alarm transition (active/non-active, ack, …)

BaseEventType.ReceiveTime

Changes when the event notification is processed by the BACnet Point Manager