SendConnectEvent is used internally to ensure that registered clients are informed when their connection is opened or closed. It is called automatically when the Connected property changes. 

SendConnectEvent iterates through all registered clients. For each client that supplied an event handler to the RegisterClient method, SendConnectEvent calls that event handler to inform the client that a connection has just been opened (when Connecting is true) or that the connection is about to close (when Connecting is false). If the client is a dataset, it is informed about the change even if it did not supply an event handler to RegisterClient. 

DataSets 

Connected 

RegisterClient