Use Active property to set or check when an event alerter has registered the Names events at a DBMS and waiting for events. 

Set the Active property to True to register the events at a DBMS and start processing of incoming events. If an AnyDAC DBMS driver supports few event alerters, then the event alerter kind must be explicitly assigned to the Options.Kind. 

Set the property to False to stop processing of the events.

property Active: Boolean;

Database Alerts, Names, Register, Unregister