Applies To:
  • CitectSCADA 5.21 SPK C

I have a rather large system with multiple nodes.  What do I have to be careful of when using alarm properties as variable tags? 

There are a few things that you have to be aware of when using alarm properties as tags.
  1. If you choose to use Alarm Properties, you have to configure the alarm device under Communication | IO Devices in the Citect Project Editor.  The Alarm Server(s) MUST reside on the IOServer(s) that the alarm device(s) is(are) configured under in your project.  If you don't want the Alarm Server(s) to be on an active IOServer(s) then you will need to configure an IOServer(s) that is specifically for the alarm device(s) only and enable the IOServer on the Alarm Server node.
  2. Writing to Alarm Properties changes the appropriate alarm database file on both the primary and standby alarm server ONLY.  If you are writing to alarm properties from a Display Client, the appropriate alarm dbf file is changed on the Alarm Server(s).  If you have a distributed project that is physically on the Display Client, the Display Client's alarm database file will NOT be changed only the Alarm Server(s).
  3. If you are using Include Projects that have alarms defined in them and you write to an Alarm Property that is associated to an alarm in an Include Project, the appropriate alarm database will be updated.  The rules from point 2 apply to this as well.
  4. If you are using a File Server(s) and the Alarm Server project is linked to the File Server(s) then writing to the Alarm Property will change the appropriate alarm database on the File Server(s).