AgsDataConnectionManager is a singleton you can retrieve its instance by calling
AgsConnectionManager* ags_connection_manager_get_instance()
.
It usually provides AGS_TYPE_CONNECTION subtypes, like AgsAudioConnection which does
provide about assigned soundcard and its channel mapping.
AgsConnection contains one single property :data-object. As you provide a message queue consuming libags.so.1, you can retrieve modifications asynchronously. How the message queue is polled is explained in chapter 3.