I knew there was a catch!

[Tally Ho]

I have been trying to interface my Lowrance Link-8 AIS/DSC VHF Radio with my Garmin 740 Chartplotter using NMEA2000.

This boat is fairly new to me, and I just started trying to figure out some of the electronics the PO had installed.

Despite having a NMEA 2000 backbone, and both of the devices connected, neither could "see" the other. Finally realized that there was no power input to the NMEA network.

Ordered a Garmin NMEA2k power cord, wired it in, and viola! The Chartplotter suddenly had access to AIS data from the radio. And the radio shows the Garmin 740 on the list of GPS sources....Success!

Well, not so fast....

Still had that *^%}|€££| alarm from the radio and an error saying that it had no GPS data. Checked all of the connections, checked all of the settings on both devices, but still no GPS data on the radio.

Today I was searching the web for more help, and found articles that say that there is a known issue with the Link-8, and that it won't (despite supporting NMEA2k), read the GPS data from a chart plotter.

But wait! They released a software patch that can be downloaded to an SD card, loaded in an MFD connected to the network, and upgrade the radio.

THE "CATCH"------The instructions say "a compatible Lowrance MFD".

I have a feeling the upgrade won't work from my Garmin 740, but I have the software patch loaded on an SD card to try the patch tomorrow.

Here is a link to the Lowrance Link-8 upgrade site if anyone is in the same boat. The update was released in November 2015.

http://www.lowrance.com/en-US/Software-Updates/Link-8-Software/

If anyone else is using a Link-8 with a Garmin chart plotter successfully, I would love to hear how you did it.

Greg

 

[Allan12210]

At least for the short term until you figure out how to get the Chart Plotter data to the VHF, can you run a single NEMA 0183 wire back to the VHF? I know that's the purpose of the network system, but for now, perhaps a parallel approach might get you what you want for the short term. My new Garmin 547xs GPS/Chartplotter and B&G V50 VHF/AIS have provision for both 0183 and 2000. Since I don't have much else than those two devices I'm still using the 0183 communication.

 

[Allan12210]

I just thought of something else. Do you have an autopilot that follows instructions from the plotter as well? Is that working on the 2000 backbone? Will the autopilot follow a track you input on the plotter (go to...)? If that isn't working either then something in the plotter doesn't seem to be switched on to provide the necessary signal out. Again, you could try the NEMA 0183, even temporarily to see if any data comes from the plotter. The appropriate data input choice has to be selected on your receiving device menu (in this case NEMA 0183).

 

[Tally Ho]

Hi Allan,

I have thought about the NMEA 0183 connection. The VHF and Chartplotter both support 0183, but I think the 0183 connection on the Chartplotter is connected to other transducers. Honestly, I am not sure how you "tie in" to the existing wiring. At least with N2K, it is sorta "plug and play" for us non-electrical people.

The AP is not connected to anything as it is an older Raymarine with Seatalk.

I tried to upgrade the software on the VHF today, plugging the CF card with the upgrade file into the Garmin CP. As I suspected, it does not work. Must need a Lowrance MFD.

Thanks for the tips and ideas.

Happy 4th!

Greg

 

[Allan12210]

Hi Greg,
Well that is a shame that the software update did not work. I checked the schematic on your radio and the 0183 input wires you would look for are the green (-) and yellow (+). Since everything is on a common ground, you probably only need to connect to your yellow wire on the back of the radio (if you can get to it). The nice thing about 0183 is that it is "one talk, many listen". So even if the chartplotter 0183 output goes to a different transducer, it can be daisy-chained to your radio and it should show position data on its display. That's how I did my autopilot. The wire went from my gps/plotter to the screw terminal on the Raymarine autopilot circuit board. Then I ran a second wire from that same screw terminal to my VHF/AIS. The autopilot gets its instructions from the gps and the position data shows up on the vhf display. I did not use SeaTalk as I have nothing else to connect it to. In your case, either the blue (port 1) or the gray (port 2) wires on the chartplotter will work as you have two 0183 transmitting and receiving ports on that device. Those two wires are the transmitting half of each port. You seem to have taken care of the receive requirements with the 2000 network. Usually one 0183 port is used to send position data to the radio and its receive counterpart brings DSC info back to the plotter at low speed (4800 baud). The other port can be used to bring AIS info to the plotter at high data speed (38,400 baud) when not using 2000. The transmit side of that port can not be used then for position as the data rate is too high. But if its not being used for AIS as in your case, it can be set in the menu for low speed as well. If you can get to the connections from the plotter easily (maybe under your compass) you should find those blue and gray wires, and one may just not be used. Even if it is, just share the connection . Run a wire through the companionway to the yellow radio wire and see what happens. You will have to go into the setup menu and make sure the port you are trying to use is set for low speed communications (4800). I don't know what other transducers you may have that would require high speed communications, so you may be already set up on both 0183 ports.

Alternatively, if you have an old hand held GPS with the data out pins, you can just use that to feed position info into the radio. Just use a jumper with alligator clips on both ends to connect the correct pin to the yellow wire. Schematic should be on line. You may have to connect the handheld gps ground pin to the radio green as well.

Hope this wasn't too confusing. It took me a little while to get mine running a couple of months ago. The worst was fishing wires from one end of the boat to another. Best of luck trying to sort it out.

Allan

 

[Tally Ho]

Thanks Allan,

Let me digest this. I think my challenge will be to tie in to the 0183 input for the CP.

I will be out at the boat later today and will take a look at the 0183 wiring.
But I think you are right...this is the only way to get them networked. Or I need to buy a new radio. I have an old VHF in the cabin at the nav station that barely works, so maybe I will move the Link-8 there, and buy a N2K compatible for the helm.

Greg

 

[Joe]

If you have your vhf on the n2k network, as long with the chartplotter, you must instruct it to choose the chartplotterm as its GPS source. You will find this option in the "menu" under "radio setup". Going to the "GPS source" box you will find "0183" and the name of your chartplotter....which is the n2k backbone. Simply chose your cp and you're good to go.

If you don't find your cp unit noted...it is not connected to the backbone.

If discover that your cp is not n2k compatible, you may go the nm0183 route. You can also try an adapter cord, I used one for my tiller pilot....or install an n2k GPS antenna..
Ps..
I re read your thread and looks like I'm telling you something you already know. My apologies if this is old news. Good luck. Hope you get it sorted out. Joe

 

[Davidasailor26]

One other option you could try - if you find someone around with a Navico chart plotter (Simrad/Lowrance/B&G) you could carry your radio to their boat and tie into their network to do the update.

 

[Tally Ho]

If you have your vhf on the n2k network, as long with the chartplotter, you must instruct it to choose the chartplotterm as its GPS source. You will find this option in the "menu" under "radio setup". Going to the "GPS source" box you will find "0183" and the name of your chartplotter....which is the n2k backbone. Simply chose your cp and you're good to go.

If you don't find your cp unit noted...it is not connected to the backbone.

If discover that your cp is not n2k compatible, you may go the nm0183 route. You can also try an adapter cord, I used one for my tiller pilot....or install an n2k GPS antenna..
Ps..
I re read your thread and looks like I'm telling you something you already know. My apologies if this is old news. Good luck. Hope you get it sorted out. Joe

Thanks Joe. I found out that themPO never hooked a power supply into the N2K backbone, so neither device could see the other. Fixed that, and both devices "see" each other, but GPS data from CP not showing up on the VHF.

Turns out there is a software bug with the VHF.

Will have to try to use 0183 connection for the GPS data.

Greg

 

[Tally Ho]

One other option you could try - if you find someone around with a Navico chart plotter (Simrad/Lowrance/B&G) you could carry your radio to their boat and tie into their network to do the update.

Yes. I thought of that too. Will start checking with my slip-mates to,see if anyone has the correct MFD.

Great suggestion.

Greg

 

[wolfpv]

Tally Ho,
Sorry to resurrect an old thread...but...
I recently bought a Link 8 and HDS 7 Carbon, plus a Point 1 GPS antenna and a 3G radar (completely renewing all the ancient electronics on my sailboat). Everything is fine, except that I can't get AIS over NMEA 2K to display on the HDS. Everything else is fine, and the HDS recognizes the Link 8 on its device list... just on AIS. The radio sees the GPS antenna and gets its position. Lowrance tech support wasn't very helpful, but they seem to think the radio only sends AIS over NMEA 0183, but your comments above certainly seem to indicate that the radio can communicate AIS over NMEA 2000. Is there some secret to setting this up?

 

[jssailem]

Hello @wolfpv and welcome to the forum. It makes sense to try an old thread but sometimes the existing subject heading is not enough to attract the eye of the members to help solve your problem.

If I understand your query you are trying to get the AIS info from the receiver in your new VHF radio (Link-8) to show on a plotter (the HDS Carbon7)?

WOW... Well based on my limited reading of the specs of your parts online (ripping sound as I yank the bandaid off)

I do not think you can.
The features on the radio state:

NMEA 2000 ® (micro-C connector) NMEA0183 (cable included) in for GPS Position (RMC,GGA,GLL,GNS); out for DSC messages to GPS/Plotter (for DSC call), DSE (enhanced position), 4800 Baud​

It says nothing about transmitting AIS signal to the NMEA 2000 backbone. I would call Lorance support and ask if the radio outputs the AIS signal to the NMEA 2000 network.
Second the HDS Carbon7 is a Fishfinder with a chartplotter. It says it connects to the NMEA 2000 network but no info is provided about networking. There needs to be the circuitry to read the NMEA signal and then display the info. Again Lorance Support. Or a manual that is more in-depth than the one on line that I found.

You might also try to post a question on the forum. Subject. “Connecting Lorance HDS Carbon7 to VHF Link-8 radio to get AIS - HELP.”

Maybe someone has done it. I am not to hopeful but then sometimes things happen.
Best of luck.

 

[Tally Ho]

I did not see that @wolfpv resurrected this thread, but he did PM me.

My problem was that I could not get my GPS coordinates shared between the CP and the Lunk 8. I was able to get the AIS targets shared to the CP just fine via NMEA2000.

I believe the issue was a software issue in the Link 8, but I did not have an easy way to update the software. I also think that if I had a separate GPS antenna, I would have been Ok. But I did not want to purchase one.

In the end, my Link 8 died, as did the ancient VHF I had at the nav station. So I upgraded to a B&G V50 (with AIS) and it communicates with my CP as intended. With the H50 handheld in the cockpit and V50 base station at the nav station, I have a very workable communication solution.

@wolfpv PM’d me that he now has all of his instruments talking to each other, so a happy resolution to his problem.


Greg

 

[jssailem]

Thanks Greg. Perhaps he can share his resolution. The support online did not look positive.

 

[Tally Ho]

Sounded like he directed his VHF to use his external GPS for coordinates, and then switched it to use the CP for coordinates, and it started working.

My understanding was that there was a software glitch in early versions of the Link 8 that caused the GPS interface issue. I didn’t have a Lowrance CP, so could not flash the software. It may have been fixed in the unit @wolfpv is using. I seem to recall that the glitch was specific to interfacing with a Garmin CP.

Greg

 

[jssailem]

So AIS signal is produced by his radio receiver and broadcast in the seatalkng backbone? The limited online feature description did not include that as being output from the VHF Radio.

 

[wolfpv]

Yes, I was trying to get the AIS information (packets) from the radio to be recognized by the chartplotter. Nothing worked, and then it started working...beautifully. The only thing I did was change the radio's GPS input to the chartplotter's built-in (which might have gotten them talking) - but I then changed it back to the Point-1 antenna and it continued to work. I may have hit it once or twice, which is (as we know) the idiot's solution to all technical problems. My goal in all of this was to have a simple setup with radar, charts, and AIS all overlaid on the chartplotter, and also shared via wifi with a tablet at the nav station. It all works now, and as a sextant-and-RDF navigator (on my last extended cruise) I'm in tech heaven.

 

[jssailem]

Good news. It is interesting that the VHF manufacturer would not include such a neat feature in their promotional material.

Thank you for providing the rest of the story.

Never discount the value of giving your electronic equipment a good wack. If it doesn’t fix the unit it (as it occasionally solved the problem) it will sometimes stop you from throwing the equipment overboard.