Helllo,
The Blue Robotics site said that the Tether has a maximum distance of 300m for a good signal to handle video and cmd send to the ROV and a depth rated of 950m.
I see some people trying the depth but there is no information on the cable.
If I only want to take pictures with a 100 to 200Kbit rate one way, will the cable support that distance? In fact will it goes to 950m?
Thank you,
Pierre
Hi @Pierre021 -
Welcome to the forums!
The BROV2 can only be configured for a maximum depth rating of 300m. However, many of our enclosures and penetrators are rated to 950m! The limiting factor for the BlueROV2 is the dome, currently.
The 900m depth ROV was a resident, cabled system, not deployed from the surface! It was connected at the seafloor to a system that provided it with power over tether and a network connection all the way to shore - likely using fiber optics!
The Fathom-X tether interface will not work beyond 200-300m, depending on the twisted pair used. Newer versions may manage farther, but generally to reach that distance fiber-optics are required - at least as far as I know! For only 100-200kbit, it may be possible to use other protocols to cover the distance, like RS485. It’s equally about the type of communications, as well as the conductors used!
Yes, I am using RS485. I used 300m of CAT6, not in water, this is working fine of course. I am not using with a ROV, just the enclosure, sensors, camera for pictures.
Now I want to test more distance but doubling it with CAT6 which is 24AWG will not make much sense for the goal just above 1000psi. I will be surprised that these cables take that pressure and I am not sure about the connection even if HDpt is selling 5000psi marine epoxy.
The CAT6 I am using is 24AWG and the tether, more like CAT5, is 26AWG and I wonder how will this handle the distance.
The real question then is can I send data to a distance of 750m using BlueRobotics tether but not your interface?
I started as well to look at fiber optics, most quickly available are 50m in length. Longer than that and it is the magic expre$$ion of “request for quote”… Then I have to link all of them and maybe splice some.
For the dome, yes, 3" is rated 750m and the 2" will go the length of the depth rated cable 950m. I choose the 3" since this is what the depth I have available and I can reach it without using a Falkor (too).
Now of course there is another way to reach that depth. I was thinking about this waiting for input to my question. I can use 3 enclosures, sitting near the fiber optics, which will be the solution of last resort. This solution allows me to de-risk the spending on the cable and based on a maximum of 300m, between enclosures, a guaranty of getting data.
This was the first choice: If the 750m length cable cable can pass data than I only have to use wetlink cable splice kit. Can 750m tether pass data?
Thank you for helping to think harder and get a solution.
Pierre