You enable alarms so they change state according to the variables the alarm monitors.
In WorkStation or WebStation, in the Alarms pane or Alarm View, click the Show disabled alarms button
In the Alarms pane or Alarm View, right-click the alarm and then click Enable alarm .
If you enable an alarm that has been disabled by a user (Disable cause = User), the alarm goes to Normal state for re-evaluation. If you enable an alarm that has been disabled by the System or a shunt variable, the alarm stays disabled.