Tether is working!

   I finally got my tether working. I'm following Walt Holm's work with OpenROV and adapting it for my vehicle. I can currently transmit about 20Mbps across a single pair of wires (500' spool). Theoretically I should be able to do 200Mbps, so I'll see what the current limitation is. It's probably the USB port on my laptop. Since I'm using a MacBook Air, I don't have an ethernet connection, so my connection works as follows:

Beaglebone > cat5 > powerline ethernet adapter > single pair wire > powerline ethernet adapter > cat5 > USB-ethernet adapter > USB > laptop

Easy, right? I'm only getting a few milliseconds latency, so it seems to be working just fine. The black box contains the USB-ethernet adapter and a powerline adapter that is powered from a 3.3V USB power supply. Both USB devices are powered from the same cable. Now all I have to do is see if I have any problems when it's stretched out to 500'.