we are working with the Fathom Tether, and have modified it to have cobalt connectors on both ends of the tether cable, with all 4 pairs in the tether connected to the 8-pin cobalt ends. We were under the assumption that with this setup, we would be able to achieve a standard Ethernet link, potentially reaching 1Gbps. We aim to connect our topside machine to an RGB-D camera, publishing high-frequency and resolution data, in the ideal case, lossless, for higher quality downstream processing.
Unfortunately, with our current setup, we are only reaching a link speed of 10Mbps, with a tether that is about 15m long.
Has anyone been able to modify the Fathom Tether successfully to support standard Ethernet connectivity?
Hi @HJGrant -
Unfortunately there is no way you’re going to get speeds like that with Fathom tether!
The tether does not meet Cat5/Cat6 ethernet cable specification, as it uses stranded instead of solid core copper wire (this greatly enhances durability.) In addition, cobalt connectors (and any connector that is not RJ45) can interfere with ethernet signals, reducing bandwidth.
Sorry for the news!
10Mbps does seem lower than I would expect for that short of a tether… You could try using a Fathom-X to have a single pair carry around 80Mbps, or other versions of the Lx200 that use more than one pair may achieve faster speeds. Gigabit over the tether may only be possible with a g.hn protocol solution - the Blue Robotics R&D team is working on such a solution that will upgrade tether communications offerings in the future!
