MemoryAlarmService is an alarm service that provides an alternative to the standard file-based AlarmService. A station should have only one alarm service. Do not enable both the standard AlarmService and MemoryAlarmService on the same station.

Each station may contain a single alarm service that coordinates the routing of alarms within the NiagaraAX framework. The memory alarm service is available in the alarm palette, as shown in Figure 194.

If you do not have the memory alarm service in your active station, you can add it by dragging and dropping a copy from the alarm palette, as shown in Figure 195.

Like the alarm service, the memory alarm service may contain one or more alarm classes. An alarm class may route alarms to one or more alarm recipient types.

The routing process for the memory alarm service is the same as the standard file-based alarm service and includes alarm acknowledgements from the recipients back to the source, and alarm notifications from the source to the recipients. The default view (wire sheet view) of the alarm service makes it easy to visualize the relationships between the alarm class and the alarm recipient. These relationships are created by linking the alarm class to the alarm recipient, as described in About alarm class. The memory alarm service has the same views available as the standard alarm service.

The main distinction of MemoryAlarmService is that when you use this service, alarms are not stored persistently on the station host (typically a JACE) as they are with the standard file-based alarm service. Choosing MemoryAlarmService might be appropriate for situations where you do not want to keep a large store of alarms on your host and are looking primarily for immediate alarm notifications. Alarm records are stored in memory and therefore they are lost in the case of a power failure.