Fathom X link light not on

[kingcoolance (Murari Gubba)]

Dear Team,

Approximately six months ago, we purchased a fully assembled Blue Robotics electronics enclosure. It has been functioning reliably up until now; however, we are currently experiencing an issue with the Fathom-X system. The link light on the onboard unit no longer turns on, and a connection is no longer being established.

For context, the topside setup uses the OpenROV HomePlug adapter (a counterpart to the Fathom-X), which was working correctly as recently as yesterday. Today, however, we are unable to ping the ROV at 192.168.2.2, and the link light on the onboard Fathom-X remains off.

To troubleshoot, we connected the computer directly to the Raspberry Pi via Ethernet, and communication worked as expected. This suggests the issue is isolated to the Fathom-X system. We have also verified that tether continuity is intact. While the tether is not a Blue Robotics tether, it consists of a single twisted pair and appears to be functioning properly.

Do you have any suggestions on what might be causing this issue? Attached below are pictures of the OpenROV homeplug adapter for context.

[tony-white]

Hi @kingcoolance -

That sounds like a case of failed hardware to me! If you’re using that OpenROV adapter, it must be at least 6-10 years old? Either the Fathom-X or the topside adapter is having an issue, assuming the resistance of the two wires in your tether was equivalent.

You could troubleshoot further by connecting the tether normally, reaching your vehicle at its IP address on your local WiFi network (found before disconnecting the standard Ethernet cable, by connecting to a WiFi network in BlueOS and checking the IP address assigned via DHCP), and installing the tether diagnostic extension. It will communicate with the tether module, and present some graphs. Screenshots of those are helpful - generally you want the pink and blue lines close together and indicating theoretical max bandwidth to be above 70 (graph in upper right.)

A Fathom-X for your topside, potentially packaged in the convenient form factor of the FXTI box should get things working again.