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Putting payload data on the tether

(Jesper Christensen) #1

We are wondering if it would be possible (and easy) to simply put the tether on the vehicle side into a switch which then also could be used for ethernet payload data stream to the surface and remain with 1 tether instead of multiple?

(Njål B.) #2

Hi Jesper,

Yes, no issue at all, you have plenty of space for it. I just threw it in, but you can find other spots for it which are better. Mini ethernet switch

You have to terminate the RJ45 connection to the Rpi and BR-2-wire communcation, but you get the connectors with pigtail for the switch ethernet and power connectors included.

(Jesper Christensen) #3

Hi Njål,

Thanks for your reply!
So no other modifications needed? Just put on a switch, and everything still works with QGroundControl as per usual and along with whatever data may be streamed from e.g. ethernet camera or sonar viewed in separate software?

(Njål B.) #4

Thats correct. I actually have two of them subsea, one in a extra bottle and one as in the picture with no compromise on the data transfer rate.

(Jesper Christensen) #5

Thank you very much. Will try that out :slight_smile:

(Njål B.) #6

Cool, hope it all works out!

The switch comes with chinese imprint so you have to look at the pictures for Tx and Rx configuration and the same for the 4-pin power. I used the 5V going to the Rpi for powering the switch.

I have put it on a 6 pin pigtail. Pin 1-4 ethernet and pin 5-6 with power. Really handy to be able to disconnect the external stuff in the secondary pod quickly and just blank the pigtail end if diving without the extra bottle.

1 Like
(Jacob) #7

As @Bragstad pointed out, you can do this! The system works like any other normal Local Area Network.

(Jesper Christensen) #8

@jwalser I have successfully tested with a different variety of sonars. I am however having issue with a GigE camera from FLIR. When I connect the camera and the laptop through the Chinese switch (100mbit) we installed I have no issues at all. When it then connects through the tether and Fathom box it does not work. I can see the camera and connect to it, but it cannot push any data through.
Any advise for this?

(Marcus) #9

I think most GigE cameras exceed 100 mbps (???). You might be getting lucky with it working via ethernet through the switch (are you sure it’s only a 100mbps switch?), but you are probably getting much less bandwidth using the homeplug (Fathom) system (test it via Even with the shortest of cable lengths, I’ve never seen in excess of 80mbps available bandwidth which is probably not sufficient for a GigE camera.

(Jacob) #10

We need more information about the situation. If you are talking to the camera, then the network connection is working. What program are you using, how are you determining there is no data being ‘pushed through’, have you seen any error messages? Also, @spotxuv is right, the fathom X is only 10/100 ethernet.

(Jesper Christensen) #11

@jwalser @spotxuv the camera supports 10/100/1000mbps.
I am using FLIR spinview to connect to the camera and grab images. When connected through the tether, packages are dropped, connection falls out and once in a while when an image comes through it is just a few lines of the image. Connecting the laptop and camera directly through the 100mbps switch non of these issues arises.