$session->propertySubscribe( $object, $property, $interval )
The propertySubscribe() function subscribes to notifications of changes to the specified object property. “Event subscription” on page 22 provide an overview of subscribing to events in a Domain Manager.
The actions of this call are reversed by propertyUnsubscribe().
$session->propertySubscribe( "Router::gw1", "Vendor", 30 );