06 May 2010

Lowrance yellow Ethernet cabling

The Navico 'yellow' ethernet connector used on new Lowrance devices such as the HDS series has the advantage of being watertight and easy to make a reliable twist-on connection:

Navico Yellow Ethernet connector

In case you want to use a standard Ethernet switch, or have guys lay ethernet cabling through some narrow ducting you cannot use the normal Lowrance Ethernet cabling and have to crimp an RJ-45 jack onto the Lowrance cable.

On opening up the cable I found two twisted pairs of cable, as expected, plus a shield:

Navico Ethernet cable pairs exposed

The pairs are blue and orange. I connected those the same way as a 3 Com sourced very thin Ethernet cable I had lying around: blue to pins 1+2 and orange to pins 3+6 of the RJ-45 jack. This isn't according to either T568A or T568B, but that cannot be helped when the cable pairs are blue and orange. In practice the cable works fine, both when wired directly and when wired to a switch. I don't know whether the is actually a cross over cable or direct through though, so if you use a switch that doesn't do auto MDI-X you may have to swap the pairs.

Here's the crimped connector:

Navico cable to RJ-45 jack

and the final cable:

Finished Navico to RJ-45 Ethernet cable

Once plugged in a quick run of tcpdump revealed the IP address of the Lowrance HDS and a ping proves that my Mac and HDS are able to talk to each other:

PING 169.254.17.126 (169.254.17.126): 56 data bytes
64 bytes from 169.254.17.126: icmp_seq=0 ttl=64 time=0.788 ms
64 bytes from 169.254.17.126: icmp_seq=1 ttl=64 time=0.405 ms
64 bytes from 169.254.17.126: icmp_seq=2 ttl=64 time=0.480 ms

Hurrah, one more item from my to-do list done!

Update


May 2010: Commenters have asked me whether this means they can now interface a HDS or Broadband Radar to their PC. Alas, no. The test done above was just a convenient way for me to test that the munged cable works.June 22, 2010: Yes, you can! Navico has released a SDK that allows navigation software providers to interface with the Broadband Radar. As far as I know, only Expedition has released the necessary software so far (August 2010). For more information see Simrad BR24PC, Free Range BroadBand Radar #2 at Panbo.

6 comments:

  1. Pardon my ignorance but why are you connecting the HDS to you PC/Mac? Is there PC software (i.e. Navionics) that ”just works?”

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  2. Do you know how much data the Lowrance HDS transmits per sec (mbps e.g) I'm interested in logging the data to a computer.

    Thanks,

    Ash

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  3. @Mic: No, and if you read carefully I never said that this was going to be the permanent setup. I want to be able to have freedom to wire up Ethernet cabling the way I want it with the connectors that I choose (standard RJ-45).

    However, I'd be surprised if Simrad/Navico doesn't come up with a software package interface sometime.

    @Ashley J: I'll know in about a month or two. At the moment we're wiring the boat up but the systems aren't live yet, and the interesting data will be how much the BB24 transmits. That will have to wait until the mast is installed.

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  4. This comment has been removed by the author.

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  5. It seems that pins in 5-pin Navico 'yellow' ethernet connector carry following signals:

    1. Tx+ - blue/white
    2. Tx- - blue
    3. Rx+ - orange/whit
    4. Rx- - orange

    You can make cable with connectors at one side and rj45 on the other, where rj45 is connected as written above (1+2 blue/white and blue, 3+6 orange/white and orange).
    Using two such cables I was able to connect LSS and HDS via ethernet switch and some length of cable.
    It worked fine.
    The point was to test ethernet connection and to not to cut Navico cable.

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  6. I will like to make my own cables: where can I buy the ethernet yellow connectors?

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