Enable Alarms - Independent Enabled on the Server

The Enable Alarms action allows you to re-instate the alarms and alarm features for an item (that has its alarms currently disabled). But the way in which the Enable Alarms action is applied varies according to whether the Independent setting is enabled or disabled on the server.

The Independent feature is designed to stop potential conflicts between users, Schedules, Logic, and Method Calls when using Enable Alarms and Disable Alarms. It works by using ‘flags’ for each of the internal User Types (User, Logic, Schedule, Method Calls), and an Overall calculated ‘Disable Alarms’ state. The ‘Disable Alarms’ state indicates whether the alarm features are enabled or disabled in ViewX and WebX.

In this section, we explain how ClearSCADA applies Enable Alarms when Independent is enabled. For information on how Enable Alarms works when Independent is disabled, see Enable Alarms - Independent Disabled on the Server.

To understand how Independent affects Enable Alarms, you need to be aware of:

• The internal User Types (User, Logic, Schedule, and Method Call)
• The ‘Disable Alarms’ flags for each internal User Type
• The Overall calculated ‘Disable Alarms’ state for the database item.

These concepts are described in the Server Administration Guide (see Alarms Settings in the ClearSCADA Guide to Server Administration).

If Independent is enabled on your server, the Enable Alarms action works as follows:

1. The Enable Alarms action is triggered, either manually by a user, or automatically by a Logic program, a Schedule, or a Method Call.
2. The ‘Disable Alarms’ flag is set for the appropriate internal User Type:
   • If Enable Alarms was triggered manually by a ViewX or WebX user, the User ‘Disable Alarms’ flag is set to 0.
   • If Enable Alarms was triggered automatically by a Logic program, the Logic ‘Disable Alarms’ flag is set to 0.
   • If Enable Alarms was triggered automatically by a Schedule, the Schedule ‘Disable Alarms’ flag is set to 0.
   • If Enable Alarms was triggered manually by a Method Call, the Method Call ‘Disable Alarms’ flag is set to 0.
3. ClearSCADA considers the ‘Disable Alarms’ flag of each internal User Type to determine the Overall ‘Disable Alarms’ state for the item.
   • If all of the internal User Type flags are 0, the Overall ‘Disable Alarms’ state is 0. This means that the item’s alarms are enabled for all User Types, and so the alarm features are not withheld. ViewX and WebX users will be able to view the item’s alarms and access its alarm response actions, such as Acknowledge.
   • If any of the internal User Type flags are 1, the Overall ‘Disable Alarms’ state is 1. This means that the item’s alarms no longer appear in the Alarm Banner, Alarms List and other alarm displays.
4. The Overall ‘Disable Alarms’ state is used to determine whether the item’s alarms and alarm response actions are available in ViewX and WebX:
   • If the Overall ‘Disable Alarms’ state is 0, the item’s alarms and alarm response actions are available in ViewX and WebX.

     ClearSCADA will:

     • Log an Alarms enabled entry in the Event Journal (Events List).
     • Add any alarm entries to the Alarms List and Alarm Banner. The entries will be time stamped with the alarm’s original occurrence time (or, on systems on which the Use Visible Time As Alarm Active Time feature is enabled, the time that alarms were re-enabled on the item).
     • Update the item’s color on Mimics, Lists, and so on, to indicate that it’s alarms are now enabled.
     • Update the item’s Status display to indicate that alarms are enabled on the item.
     • Allow any redirections that are configured for the item to take place. Only alarms that are detected after the item has been re-enabled can be redirected.
   • If the Overall ‘Disable Alarms’ state is 1, the item’s alarms and alarm response actions are unavailable in ViewX and WebX (until the item’s alarms are enabled again).

     When an item’s alarm features are disabled in ViewX and WebX, it means that the Overall state is 1. To re-display the item’s alarm features, a user would need to select the item’s Enable Alarms action. But with Independent enabled, selecting Enable Alarms would only re-enable the alarms if the other internal User Types were also set to 0.

     Example:

     On a system that has Independent enabled, a new point is created. By default, a new point has its alarm features enabled, so its ‘Disable Alarms’ flags and state are: User 0, Logic 0, Schedule 0, Method Calls 0, Overall 0.

     A user selects the Disable Alarms action for the point. This causes ClearSCADA to withhold the alarms and alarm features for the point in ViewX and WebX, as the flags and state are now: User 1, Logic 0, Schedule 0, Method Calls 0, Overall 1.

     While the point’s alarms are disabled, a Logic program triggers the point’s Disable Alarms action. In ViewX and WebX, this has no noticeable effect as the alarms are already disabled.

     The user then selects the Enable Alarms action for the point. But selecting Enable Alarms appears to have no effect. This is because the flags and state are now: User 0, Logic 1, Schedule 0, Method Calls 0, Overall 1. To prevent potential conflicts, ClearSCADA only applies the Enable Alarms action if all of the flags are 0; it applies the Disable Alarms action if any of the flags are 1.

If Enable Alarms is selected or triggered and appears to have no effect, it is most likely because ClearSCADA is using the Independent feature to stop a potential conflict. In this situation, you can use the item’s Status display to find out which User Types are disabling the item’s alarms.