Default Destination - Metasys - LIT-12011942 - Software Application - ODS Server - 10.1

Metasys Open Data Server Help

Product name
ODS Server
Document type
User Guide
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You can define an ODS repository as a Default Destination for each Engine where event messages are sent under certain conditions and permanently stored:

  • If the Default Destination is an ODS that has a LAN connection (as defined by the Engine Device Object’s ODS Connection Type attribute or the Site Object’s Default ADS Connection Type attribute), event messages generated by the Engine are sent to the ODS as they occur.

  • If the Default Destination is an ODS that has a Dial connection, event messages generated by the Engine are sent to the ODS when the local event repository is 90% full NAE object’s Alarm Repository Size attribute), at the user-defined time (NAE object’s ODS Delivery Time attribute), or when the event priority exceeds the user-defined level (NAE object’s ODS Priority Threshold attribute).

See the Site Object, Engine Device Object, and ODS Connection Type sections for information on these attributes.

For information on how to define a Default Destination, see the Configuring an Engine Event Repository section.

If you have not defined a Default Destination when the Engine local event repository is 100% full, the local event repository either replaces the oldest messages (rollover) with new messages or stops recording events according to the Event Action When Full attribute configuration.

Event message rollover begins or replacement stops only when the total number of nonforwarded event messages reaches the size defined by the Event Repository Size attribute. In other words, once the local event repository reaches the defined size, new event messages continue to enter the local event repository replacing forwarded messages until all forwarded messages are gone. The following figure illustrates the Event Action When Full when set to Rollover or when set to Stop.

Figure 1. Event Action When Full

If you have defined a Default Destination and the Event Action When Full attribute is set to Stop, the event messages do not stop rolling over as long as forwarding is successful. This situation occurs because event messages are forwarded to the Default Destination when new event messages are received, and the forwarded messages are automatically replaced. The local event repository does not fill up with nonforwarded event messages and, therefore, does not stop accepting new event messages.

If an event repository is full when a new event occurs, the following rules apply:

  1. Events forwarded to an ODS Event Repository are always removed before events – not forwarded.
  2. The lowest priority event with the oldest time stamp and Acknowledge Required set to false is replaced first.
  3. If the event about to be created is of higher priority than at least one event in the repository, the event with the oldest time stamp and lowest priority is replaced.
  4. If all events are of the same priority, the event with the oldest time stamp is replaced.
  5. If the event about to be created is of a lower priority than all other events in the Event Repository, no event is replaced and the new event is discarded. In this situation, the new event does not cause the Alarm Window to appear, or any other DDA action to take place.


  • The local repository for alarms in the NAE is set to rollover at 1000 alarms automatically if the alarms meet the above requirements.
  • You can define only one ODS Repository as the Default Destination for an Engine; however, different Engines can have different ODS Repositories defined as their Default Destination.

You can forward event messages from one ODS to other ODSs on the same site. For details, see the Configuring an ODS Event Repository section.