When a device is sending any traffic, the device is considered to be connected. If no traffic if being received from the device, a status is requested. If the device fails to report the status back in a timely manner, it is considered to be disconnected.
If the device fails to reply to the status request, it is important to confirm that the device is not applying settings. While the device is applying settings, it will not be sending heartbeats or able to process a status request.
Kyle Schwarz
Paul Hollinsky
EricLiu2000