An alarm banner is a list showing only one unacknowledged alarm.
By default, each new unacknowledged alarm overwrites the previous one as long as the object is visible.
If the Queue new alarms check box on the Alarm tab of the Alarm Banner Properties dialog box is selected, new alarms do not overwrite previous alarms, but are queued in the order they occur. The alarm banner shows the first of the queued unacknowledged alarms. The operator has to acknowledge each alarm individually by the Ack Alarm button or the Ack All button to remove it from the queue.
Set up general properties for an alarm banner