Fathom-E Tether Interface Board Set (Retired)


The Fathom-E boards provide an easy way to use the Fathom tether or a Cat5+ network cable for standard Ethernet communication.

Out of stock

HS Code: 8504.40.40

Product Description

The Fathom-E Tether Interface Board Set is a simple and affordable tether interface board. It basically just connects the tether to an RJ45 Ethernet jack without the need for connector crimping. The tether screw terminal interfaces with the Fathom tether or any standard Cat5 cable with four twisted pairs of wire. It has the following features:

  • 100 Mbps Ethernet over up to 100m of tether
  • Screw terminal for easy tether connection
  • RJ45 jack and included 6″ Ethernet cable
  • Matching screw holes with Fathom-S/X for easy upgrade

If you need a tether interface for longer tether lengths (>100m) or you want to have more tether pairs available for other purposes, check out the Fathom-X Tether Interface.

The Fathom-E Tether Interface Boards are 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.


  • 2 x Fathom-E Tether Interface Boards
  • 1 x 6″ Ethernet Cable


Schematic/Layout Design Files (Github)

Revision History

15 June 2016

  • R1 – Initial Release

Quick Start

The Fathom-E tether interface board connects the Fathom ROV tether to an Ethernet port. The board inside the ROV is used to connect to a companion computer Raspberry Pi. It is also used to connect the tether to an Ethernet port on the topside computer.


    1. Connect one end of the RJ45/Ethernet cable to the board. Connect the other end to the topside computer or onboard ROV computer.

    2. Connect the tether wires to the respective color coded terminals on the board.

    3. Check to see if the Ethernet connection is established.

Note: This board cannot be used with the Fathom Slim ROV tether.

Support Community

Blue Robotics Forum – Tether Interfaces