This may be a dumb question, but it’s not actually mentioned anywhere that I can see.
Since the Fathom-X is designed as a power-line interface, it there any reason I can’t use the same two tether lines to feed DC power to my ROV? (power and data just like the original purpose of this IF chip)
If so, assuming it’s designed to be compatible with 110 VAC power, then I can probably run 52V DC down the tether, yes?
Phil.
Hi Phil,
The Fathom-X board is not actually capable of functioning with an AC current of any voltage along its data lines, this will defintely fry it. However, DC current should not be a problem, and we have tested it at up to 48v with no issues.
-Adam
Cool. Another Fathom-X question.
Your page (and the specs) say we can have multiple power-line interfaces on one pair of lines.
How do these multiple access points appear the connected ethernet devices?
Is it just like a dumb hub where the IP’s of the connected devices provide the addressability, or do the Fathom-X boards themselves need to be configured with unique addresses?
On a short tether (100ft) how many of these devices do you think are “practical” to co-exist on the ROV (independant of total data-rates) ?
Have you tried AC power line? Why do you think it will fry the board? You have the high voltage blocking cap, so I was hoping to use it for power line networking. What would I have to change on the PCB design to make it work?
Hi Jarrod,
Its true we have the high voltage blocking circuitry on the Fathom-X, but we removed the zero point crossing detection module necessary for transmission over AC current. We haven’t tested the Fathom-X module over AC, so we’re not sure exactly what would happen, but you would need to add this component for proper operation. We do have some old development boards with this capability, if you’re interested you can email me at adam@bluerobotics.com for more information.
-Adam
How data is transmitted between two Fathom-x using two wires, is it synchronous data transmission, and why one board’s tether input + and - connect to another board’s tether input + and -.
Hi @590,
I myself am not intimately familiar with the inner working of the HomePlug technology. If you are interested in specific details, I recommend you take a look at Qualcomm/HomePlug Powerline technical documents such as this that describe the standard and how it works to gain a thorough understanding.
-Adam