Lowrance NMEA 2000 Network Basics

For your viewing pleasure.

Thanks for the post! I’m planning on upgrading my boat by adding an Xi5 and an HDS 9 Gen 3, in addition to the HDS Gen2 I have already. I plan on putting the 8 up at the bow, so would my best networking setup be two T connectors at the bow for the 8 and the Motorguide, with one extension cable down to my console, which would have the HDS 9, the power cord (I imagine I want to hook the circuit into an accessories switch so it’s not running 24/7?), and two Ts, one for the 9 and one for the power cable? Thanks guys, excited to finally be able to utilize all this awesome technology!

Tmf, sounds like you got it. Just a heads up get the nmea 2000 network expansion/extension kit instead of the motorguide kit. The motorguide kit has a really short nmea cable. I found this out the hard way. Its only 5′ long. The lowrance one is 20. That will reach from your now unit to the console.

Thanks for the heads up, the Lowrance one looks like it comes with a 2′ and a 15′ cable, so that should be perfect for running the HDS to the junction at the bow, and then connecting that junction to the main hub at my console. I assume the Xi5 Gateway cable connects directly from the trolling motor to the T connector? I plan on hooking up the TM ducer to the HDS 8, and etherneting the two units so I can see the SS stuff on the 8 if I’m up front, and also be able to see both broadband ducer signals on either unit.

P.S. Brainfart question, but I forget, if I have the HDS 8 ethernet-ed to the SS module, as well as the 9, will that allow me to switch between broadband ducers, and share GPS waypoints/data as well? Or will I still need to connect the two units to the NMEA network?

Yep, the T connector and 2′ cable will go to your HDS 8, then another t connector and 15′ lead (sorry, I thought it was 20) will go to your HDS 9.

Ethernet will allow you to share waypoints between the two, Not trails (I realize you didn’t ask that, but thought I should point it out). You wont even have to do anything but power up both units and they will appear. Pretty slick.
You will also be able to “share” transducers with Ethernet, but you have to “network sonar”. I actually don’t like doing that because it was messing with some of my other settings, but give it a shot and see if you like it.

Just for reference as well the differences between the Ethernet and the NMEA2000

I have been reverted back to this PDF file for a while. Although the web site is in Denmark the information they have is very useful and in English.

http://lowranceprostaff.dk/download/lowrance_hds/HDSSystemOverview.pdf

Thanks for the help guys! If I’m following correctly, then: Ethernet allows me to do a little more than NMEA would, but I should probably just network the units together anyway, since it’s not that much more work? What about networking GPS antennaes? I plan on getting a Pinpoint puck for the transom so my waypoints/sonar are as accurate as possible, can I switch what antennaes the units are using at any given time? Say I want to mark sonar waypoints from the bow HDS, I would want it to use the Pinpoint puck, but then I would want to use the HDS built-in antennae at a later date to get on the spot.

Nmea actually does WAY more than you could even fathom than ethernet, but the secret is are those things that matter to you.nmea allows all sorts of radar, outboard diagnostics, sonic hub, etc.
Ethernet is essentially only for waypoints and sonar. More useful for me anyway…
Regarding the pinpoint gps, yes, you can share it with any networked unit but keep in mind if you are reading sonar on your front gps, but the pinpoint is mounted at the transom what you see on screen won’t really match up. I think it may be best to just dedicate one unit to using the pinpoint and make sure it’s mounted as close to your transducers as possible.
You might be over thinking it a bit since gps accuracy is often greater than the distance from now to stern of a typical boat so I don’t know how much it makes a difference. Obviously the closer the gps puck and transducer are to each other the better odds you have of match up what you see on sonar to gps chips and waypoints but it may still be off a bit.