PubSub topics and systems

The Application Calculation Engine (ACE) Configuration (aceconfig) routines can have PubSub inputs defined to run on a specific system, or on the system where the ACE is running.

To configure a PubSub input to run on a specific system, you can identify the system name in the PubSub topic as shown below:

es.realtime.ace.singleruntime

In this case, regardless of the system that the ACE is running on, it will subscribe to the PubSub topic on the specified system, which is the Engineering System (ES) in this case. The value associated with the topic string will be obtained locally if the ACE is running on an ES, or through Inter-System Publish/Subscribe (ISPS) if it is running on a different system.

You can configure a PubSub input so that it runs on whichever system the ACE is running by using the %system% flag. This flag works as a prefix to the PubSub topic string, and causes the ACE to subscribe to the local system. Here is an example:

%system%.realtime.db.analog.ana1.curval

If the system that the ACE is running on is main, the string above will cause a subscription to be made to the topic main.realtime.db.analog.ana1.curval. When a mode switch occurs, the subscription will change to the owning system because the system flag has been used.