Hi, i’m currently building an underwater ROV, and i’m planning to use around 40m of fathom tether to connect the blue robotic’s ethernet switch inside the ROV the to the laptop.
Since the fathom-X interface board are for long distance communication, can this setup work without the fathom-X interface, with just two rj45 connector at the ends?
If so, what bandwidth can I expect to get with this setup?
I would really appreciate any insights on this, thanks!
Hi @SmokeySalmon -
Welcome to the forums!
Because Fathom tether does not meet the cat-5 specification, a link at that distance using two twisted pairs and regular ethernet communications is not likely to succeed! Stranded wire is used for flexibility, instead of solid-core… The Fathom-X tether interface will provide ~70-80 Mbps over just a single twisted pair without issue!
I’d recommend trying regular ethernet, and if you have connection reliability / bandwidth issues, installing the tether adapters.
Thank you for your reply! In this case I’ll try a regular ethernet cable without the interface first.
But I’m also planning to use the Blue robotics ethernet switch to communicate with two microcontrollers over the tether and the Fathom spool for organisation. Then from what I’ve gathered, the ethernet switch uses only two twisted pairs inside the tether, and the spool has a slip ring core with binder 770 connectors.
Would any of these features affect the bandwidth over a regular ethernet cable?
Hi @SmokeySalmon -
You should be fine with a 40m cat5 or cat6 cable going from the ethernet switch to a topside ethernet connection, going through the slip ring and binder connector - maybe not to a full 100mbit, but likely very close!
Great! Thanks for you help : )