NMEA networking between chartplotter and radio

S

Steve-in-SEA

New member
I thought I'd share my experience getting a Garmin chart plotter (ECHOMAP Plus 64cv) and Standard Horizon VHF (Standard Horizon GX2400) to talk to each other via NMEA, in the hopes it might save someone else some time.

I started by networking the two devices with a NMEA 2000 backbone kit from Ancor Marine, but neither device would see each other.

I called Standard Horizon support, who did the best they could given the situation... from their perspective, it could have been their radio... or the chart plotter, the backbone, lack of power to the backbone... or some other form of user user. In the end, things still weren't working.

I next called Garmin Marine support. Over the course of an hour-long call, the support person suggested a NMEA 0138 workaround (VHF blue -> chart plotter brown, high-speed), and suggested that I try a Garmin NMEA 2000 backbone kit to see if that would make a difference.

So I ordered the Garmin NMEA 2000 backbone, and it did work. Both devices see each other. I'm seeing AIS targets on the chart plotter, for instance.

One would think that one "standard" N2K network backbone would work just as well as the next, but unfortunately, that doesn't appear to be the case.

Unfortunately, I ran out of time with the boat and so was unable to swap out components (tee connectors, power injector, terminators) to narrow down the failure, which would have been an interesting experiment.

If anyone has ideas about what may have been the trouble here, would be interested in hearing/learning now. I'm new at this.

Thanks!

PS: props to Garmin marine technical support!

References:
 
Great on getting the systems to work together. Unfortunately not all "MNEA 2000" systems are the same. That was what the "Standard" was set for. But there are small differences which often make them incompatible . Been there and done that..with failures to "read" and "talk" between different brands.
 
I've set up a nmea 2000 net on Journey On. I'm not sure, but I'd bet that everything I added was passive: wires,resistors, etc. So I accept the fact that mixing different network components doesn't work but I'm not sure why, since the interconnections are only wires and terminating resistors. The line drivers and receivers are in the device. It looks like someone tried to cut costs with simple things (wires) that didn't meet specs. If the geniuses here have a better answer, I'd love to hear it.

I would agree that one should buy the networking components that are the same brand as the devices you're trying to connect, or as close as possible. If they don't work at least you're dealing with only one brand of customer service.

Boris
 
If the geniuses here have a better answer, I'd love to hear it.
Click to expand...

Not a geniuses. But my understanding it is proprietary sentencing which may not be recognized. I had the same problem with NMEA 0183 with Furuno and Signet Marine, Both blamed the other--I finally did a work around, and never did get a couple of pieces of information to read out on the displays. I wanted read outs of all of the information: wind speed, wind direction, boat speed made good to way point, compass heading all in a small instrument above the bunk, So I could monitor all functions as we ran at night and I awoke off watch and know instantly if we had a change in conditions and course/speed.
 
I have a total mix of brands, ICOM, RayMarine, Standard Horizon VHF's and a RayMarine Plotter, and RayMarine Auto Pilot. Also a Vesper Marine AIS transponder. They all talk together and show on the RayMarine 12 inch plotter but that is all done via a "Multiplexor". These were all in place prior to NMEA2000 came along. Rodger's Marine Electronics in Portland made it all work. Great place, good folks and always helpful.

Harvey
SleepyC :moon

1_Jan_From_Inside_the_Electronics.thumb.jpg
 
Hi Tom -

I like the radio a lot, but you should note that I'm still new to boating, and that I've only had the radio on the water a few times (with boat under it ;).

Some specifics:

- It fits pretty well (for me) below and to the right of the wheel in my C-Dory 16. (There's a photo showing this in the gallery for "Behemoth" in my profile).

- Overall volume seems adequate. Note that the microphone also features a small speaker. I mounted the microphone holder at window level; being that much closer to my ear, it helps me hear it when the motor is at speed w/o needing to keep the volume too high on the main speaker.

- The AIS feature is nice. It's fun to be able to learn about nearby AIS-transmitting boats... distance, bearing, speed. I haven't had the need to use the ability to direct-call feature any of those boats just yet ;). The display/menu/button arrangement is good enough for this kind of use.

- As noted earlier in this thread, I also have it N2K'd to the Garmin Chartplotter, and the AIS integration on that unit's larger screen is nice. But, to be honest, I find myself using the AIS function on the radio's screen at least 50% of the time (say, because I don't want to mess with a plot that's active on the Chartplotter, etc).

- The radio is mated to a Morad VHF-156HD antenna, based on good advice I read elsewhere on these forums. The antenna is mounted front and center atop the cabin, just behind the navigation light, on a swivel mount so that I can fold it down. The combo seems to work well, pulling in what *seems* like distant radio chatter. I don't have much of a feel just yet about how far it can transmit, though.

- You get used to the menu system. There are enough actual buttons to get you around the features/settings efficiently enough.

That's all that comes to mind now... if you have specific questions, I'd be happy to try to answer them...

Thanks!
 
I have been contemplating a new Standard Horizon radio to connect to a Garmin Multi Function Display. My 1989 ICON radio is so old that I don't know if I could even sell it on Ebay. The various features on new radios, mainly safety features, make upgrading the radio a no-brainer.

I've seen a few places where people have had difficulty connecting NMEA 2000 items to a Garmin without using the Garmin backbone. Kind of defeats the intended purpose but apparently there is no market place down side to Garmin having a kind-of sort-of proprietary backbone. It is a little irksome and feels like they are taking advantage.

The SH GX2400 radio appears to be the same as the SH GX2200 (which I have on the Limpet) with only the addition of being able to connect to NMEA 2000 (the GX2200 is only NMEA 0183). For the convenience of NMEA 2000, you pay $50. Then, instead of a standard $75 backbone, you pay an additional $10 for the Garmin product. So $125 for the convenience of plug and play (hopefully) instead of making electrical connections for maybe four wires. Again, feels like they are taking advantage.

Right now, I'm thinking of staying with NMEA 0183. If I were trying to merge other gadgets, I might think about NMEA 2000. The only gadget that comes to mind is an AIS transponder. I'm still not sure about that one.

Mark
 
Mark,
Here's the Garmin backbone for $75.60 with free shipping from BOEMarine.

https://www.boemarine.com/catalogsearch ... tarter+kit


I've become even more of a Garmin fan after my radar mount broke off while trailering, sending the entire out of warranty HDX24 dome crashing onto the boat roof, then over the side, bouncing down 200 miles of I-65 right shoulder, held on only by the network and power connectors. (What if they were 0183? ha, ha!).

I didn't have much hope, but when I put it on the new mount, it spun right up and works perfect!

How many other boaters have that experience with their delicate radar magnetrons?

What kind of $10 connectors would you be willing to pay for, if the stuff really hits your fan while boating?

I would invest in Garmin N2k for the future AIS, and future proof.

Put the ICOM on EBay, it's cheap. Some guy in CA paid me $700 for an ancient Garmin 4212 that I paid $750 for 5 years prior. I got $1,250 for an Adcom 750 preamp that I paid $750 for in 1997 (replaced it with a Yamaha receiver, of course!) You never know, but it's cheap to list for 10 days.

Best,
John
 
Getting ready to install a Garmin 94sv chartplotter with nmea 2000, and a SH gx2400 vhf with ais, also nmea 2000. I've been searching the internet trying to understand what a nmea network/backbone is, and I kept thinking I was missing some middle unit, or module, or something. Instead, it appears to just be a number of cables (like what appears in a nmea starter kit online).

Please excuse my ignorance, but am I right? I'm familiar with computer systems, which usually have some sort of interface between devices? Anyway...

If it's just cables, seems like a no brainer, especially if you want to later add motor sensors, etc. Anyway, looking for confirmation - thanks!

Wonder when wireless will kick in and eliminate some cables :)
 
zuunami":1e8w390e said:
Getting ready to install a Garmin 94sv chartplotter with nmea 2000, and a SH gx2400 vhf with ais, also nmea 2000. I've been searching the internet trying to understand what a nmea network/backbone is, and I kept thinking I was missing some middle unit, or module, or something. Instead, it appears to just be a number of cables (like what appears in a nmea starter kit online).

Please excuse my ignorance, but am I right? I'm familiar with computer systems, which usually have some sort of interface between devices? Anyway...

If it's just cables, seems like a no brainer, especially if you want to later add motor sensors, etc. Anyway, looking for confirmation - thanks!

Wonder when wireless will kick in and eliminate some cables :)
Click to expand...

2000backbone.sized.png

Nmea 2000 is a very simple and solid way for devices to talk to each other. It is a standard that uses sentences that manufactures share. However manufactures can use there own custom sentences that other manufactures equipment wouldn't understand and would ignored. Wireless systems would be more problematic and less reliable just as they are in the computer industry.
 
thanks so much Jody for the perfect diagram. I guess it's just simpler than I expected it to be :) Still not sure why those cables need a separate power source from the devices, but that's ok :)

i understand from a video I saw that the power cable needs to be as close to the middle of the array as possible -- wonder why this diagram shows an extension cable in the middle?

by the way, I agree about wireless, I have all of our computers wired, such a better connection - just wishful thinking :)

Once again, thanks so much!
 
zuunami":3h469kzt said:
thanks so much Jody for the perfect diagram. I guess it's just simpler than I expected it to be :) Still not sure why those cables need a separate power source from the devices, but that's ok :)

i understand from a video I saw that the power cable needs to be as close to the middle of the array as possible -- wonder why this diagram shows an extension cable in the middle?

by the way, I agree about wireless, I have all of our computers wired, such a better connection - just wishful thinking :)

Once again, thanks so much!
Click to expand...

Normally you would have a terminator at the stern of the boat with some tees and what ever devices would go back there. Then the extension would run to the helm and what ever tees and devices in that area and then the other terminator. My power for the network is at the helm. You could have one terminator at the Stern and the other at the bow and then devices all along the backbone. Right now my whole network is behind the helm with both terminators. Easy to change and modify.
 
It is suggested that the power tap be in the middle of the network. However, this applies more for larger, longer networks. In a C-Dory there is usually not that many NMEA devices nor are the cable runs that long. On my boat, the power tap is one one end of the string and a terminator on the other. Works fine.
 
However manufactures can use there own custom sentences that other manufactures equipment wouldn't understand and would ignored.
Click to expand...

I think that photo of the NMEA 2000 system Jody uploaded is a great explanation of the system, although very simplistic. There can be longer runs of cable (extension cable as you called it) between the numerous connection points. That extension is referred to as the backbone. Then there are the cables that run between the connectors and the various equipment. As far as the cable itself, I have found that Garmin, Lowrance, and many others use the same cabling. Rather or not they can communicate with each other may or may not be an issue. However, Ray Marine does have it's own system, called SeaTalk. That cabling IS different! And does require adapters when intermixed with other manufacturers. I guess they feel the need to be different from most the others... :( I too wonder why the need for the power supply on the system, but I do have at least one item on it that requires powering only from the NMEA2000 and perhaps other equipment on the line does not provide the necessary power. As with a lot of electronics, the acronym PFM, explains it for me. :mrgreen: Colby
 
There are many devices out there that get there power from the Nmea 2000 network so that you don't have to run more power wires to every device. Makes for a cleaner network. Lowrance is on there third generation of connectors the first two required adapters or making your on cables to make it work. I think Ray Marine is the only hold out now. If your going to use all Ray Marine products then it doesn't really matter.
 
C-Wolfe":36ns8t9j said:
Are both terminator necessary or can one end be use to connect a device or power cable instead?
Click to expand...

Yes both terminators are required. You would just add another tee and add the new device and leave the terminators at the ends of the cable.
 
We were thinking of having the primary backbone underneath the helm box (this is a 16' cruiser), and initially just connecting the chartplotter and a VHF. Then we could use an extension cable to add Ts to the stern of the boat for other sensors. My only remaining question is whether the backbone power supply can just be from the starting battery (through the switch), as that's the only battery we use - we don't have the need for a lot of power on the boat, so don't have the other battery hooked up, just onboard as a backup. Am I misreading the following, or are we fine just hooking up to the starting battery?

From a furuno backbone installation guide: The NMEA 2000 network is designed to be electrically isolated from other circuits to prevent radio interference, so a dedicated network power source is required. The range should be 9 -16V. The network power source should be either single-point connection of a battery or one or more isolated power supplies distributed along the network, but it should not be a combination of battery and power supply connections, and each power line should have
its own fuse.
 
colbysmith":3ocfbs4t said:
... I too wonder why the need for the power supply on the system, but I do have at least one item on it that requires powering only from the NMEA2000 and perhaps other equipment on the line does not provide the necessary power. As with a lot of electronics, the acronym PFM, explains it for me. :mrgreen: Colby
Click to expand...

Lots of the sensors attached to the NMEA network get their power from the backbone. The rest of the backbone is just passive wiring.

On my boat the external GPS receiver, the fuel flow sensor, and the fuel flow display are powered from the NMEA bus.
 
Back
Top