The Fathom-X Tether Interface Board provides a high-speed, long-distance Ethernet connection to an ROV or other remote platform. They’re designed for use with the Fathom tether, standard Cat5 cable, or even a single twisted pair of wires. This board uses a HomePlug module, which leverages the robust HomePlug AV (IEEE-1901) standard for sending Ethernet through powerlines. It has the following features:

• 80 Mbps Ethernet over two wires (per our own bandwidth testing)
• 300m+ tether length capability
• Plug-and-play with no setup involved
• Onboard switching power supply with 7-28V input range
• USB Mini-B connector for powering directly from a computer on the topside
• Indicator LEDs for power, link, and data
• Included 6″ Ethernet cable for connection to onboard computer

With the Fathom-X the exact same board is used on each end of the tether. One on the ROV and one on the topside. You can even connect more than two of these boards to the same tether lines. (Not sure why you’d want that… two ROVs on one tether?!)

The Fathom-X Tether Interface Board is open-source and open-hardware, so the schematics and board files are free to view, modify, and reuse. The electrical schematic and board layout are open-source and the design files are available below.