NMEA Interface: Radio to Chartplotter

Electrical and electronic topics for small boats
Sticky
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Joined: Mon Mar 19, 2018 3:43 pm

NMEA Interface: Radio to Chartplotter

Postby Sticky » Mon Mar 19, 2018 4:15 pm

I am new to the forum and have already found various invaluable resources that have answered most of my questions here, thank you for that.

I do have a couple of remaining questions though that are still haunting me. I am helping a friend with a small craft (center console fishing boat) that has an existing Garmin chartplotter (GPS4210) and we are adding a new chartplotter (Garmin 94sv) (in addition to the original one) and a new VHF radio (Icom M330). The original Garmin is using an NMEA-2000 network connection to interface to either the radar or transducer. (I don't remember offhand which was the second networked device). He was told by Garmin a couple of times, that the older unit (4210) would not interface to the new one (94sv) (I think primarily due to the age of the older Garmin and its associated radar dome). The new Garmin does have both NMEA-0183 and NMEA-2000 capabilities, and the ICOM VHR has NMEA0-183 interconnectivity.

We are planning to use the NMEA-0183 to tie the new Garmin 94 to the new ICOM M300 to enable the GPS to share location information with the radio. That seems simple enough and thanks to the resources here, I think I know how to wire that up, which brings me to my real question.

Is it possible to use both NMEA-0183 and NMEA200 on the new Garmin 94?

If we use the NMEA-0183 to connect the GPS and radio, is there any benefit, or is it even possible to connect the Garmin 94 to the NMEA-2000 network?

Would the Garmin 94 and the older Garmin 4210 be able to share any beneficial information?

I do understand what is needed if we were to tie the Garmin 94 into the existing NMEA-200 network as far as hardware is concerned, that part is simple.

As for my wiring, here is what I propose to interface the Icom to the Garmin 94..

ICOM Radio           <-->       GARMIN Chartplotter

WHITE (Talker A) ---> (Listener A) BROWN
BROWN (Talker B) ---> Not connected

GREEN (Listener B) <--- Ground or 12 Volt negative
YELLOW (Listener A) <--- (Talker A) BLUE


Thanks in advance for any guidance and suggestions.

jimh
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Re: NMEA Interface: Radio to Chartplotter

Postby jimh » Mon Mar 19, 2018 6:27 pm

Hi--your interface of NMEA-0183 between a balanced device (both A and B signala) and an unbalanced device (only A signals) looks correct.

Both NMEA-0183 and NMEA-2000 can be used, but you should realize that a typical device will not be performing any protocol translation between the two protocols. By that I mean, for example, if DEVICE A sends some data via NMEA-0183 to DEVICE B, and if DEVICE B also has a NMEA-2000 interface, you SHOULD NOT anticipate that DEVICE B is going to perform any sort of protocol translation of the data it received from its NMEA-0183 input and pass that data onto its NMEA-2000 network.

Sticky
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Re: NMEA Interface: Radio to Chartplotter

Postby Sticky » Mon Mar 19, 2018 7:51 pm

Understood Jim, thanks for clarifying that. I understand the info would not be exchangeable across the two networks and I don't think that is a problem. I'm not sure if we are even going to tie the new chart plotter into the NMEA network. but we will go ahead and do the NMEA0183 connection between the vhf and the new chart plotter so we can get location information on the vhf from the gps. Thanks again for confirming my wiring as well.

conch
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Re: Garmin 94v lacks NMEA-2000

Postby conch » Sat Mar 24, 2018 1:24 pm

Sticky wrote:...if we were to tie the Garmin 94 into the existing NMEA-200 network...


I do not believe the discontinued Garmin 94sv has NMEA-2000.

The Garmin 4210 may be using its NMEA-2000 input port for a external GPS receiver on the network as it needs an external one, or using it for something else, perhaps a NMEA-2000 fuel sensor, or engine data.

The Garmin 4210 [supports RADAR and SONAR via black box devices that send] info via the Garmin Marine Network (GMN). The GMN ports are totally different ports on the back of the Garmin 4210, distinct from the NMEA-2000 port.

NEMA 0183 can be connected to the Garmin 4210.
--

Chuck
Last edited by conch on Sat Mar 24, 2018 8:55 pm, edited 1 time in total.

Sticky
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Re: Garmin 94v lacks NMEA-2000

Postby Sticky » Sat Mar 24, 2018 2:01 pm

Chuck, you may be correct about the 94sv only having NMEA-0183 ports, but I thought it had a port labeled NMEA-2000--could be wrong on that though. I will be over on the boat tomorrow and I'll verify that.

I need to see what is connected to the network for the 4210. I know it uses a thru-hull transducer for the SONAR input, a RADAR dome for RADAR, and a GPS receiver. I will check those all out. There are two ethernet cable connections from input devices on that unit, I do remember that, probably radar and transducer or antenna..

We don't really need the VHF to network to the 4210, as long as the NMEA-0183 network to the 94sv takes care of business, which I think it will do just fine. We'll see soon!

Thanks again to everyone for helping me on the networking. I have a much better understanding of networked marine electronics now!

conch
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Re: Number of Garmine Marine Network Ports on Model 4210

Postby conch » Sat Mar 24, 2018 2:23 pm

Sticky --I believe you will find three ports on the back of the 4210 for the Garmin Marine Network and a network port expander (GMS 10) is available should you need more. Good luck with your connections.
Chuck

Sticky
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Re: NMEA Interface: Radio to Chartplotter

Postby Sticky » Sun Mar 25, 2018 4:37 pm

An update: the NEMA-0183 connections were successful, the VHF now communicates with the Garmin 94, and the VHF display updated when we powered everything up and now displays GPS coordinates and also time of day from the shared GPS data. The VHF can also send distress vessel information to the GPS, once we get all of that setup on the VHF (it was a bit cold and flurrying today, so we cut it a bit short).

The Garmin 94 model used does have an NMEA-2000 connection, so in theory we can tie that into the present NMEA-2000 network, but that only includes the older 4210 and the GPS receiver on the T-top. The sonar transducer and radar dome for the 4210 are using the Garmin network connections, which for all intents and purposes, sure does look like standard ethernet connections to me. I don't know that we will ever tie the new chartplotter into the network, other than perhaps to share waypoints and data as such, but that can be done easily with a memory card between the two units as well, we'll see.

The good news is that everything works exactly as planned, no problem, and thank you to all who helped me to get a firm understanding of marine networking, which I had no experience with previously. All of my previous marine instrumentation work was done before GPS was even available to us laymen--the days of Loran for close to shore navigation, or a Sextant for offshore navigation. Man this new technology is some good stuff compared to the ways of old!

jimh
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Re: NMEA Interface: Radio to Chartplotter

Postby jimh » Sun Mar 25, 2018 5:42 pm

Thanks for the update on the interconnection of radio and chartplotter-GNSS receiver with NMEA-0183. I believe the NMEA-0183 standard has been around since '83 (as in 1983) and would be a mature 35-year-old standard supported by almost all marine electronics that have some data to send or receive. It can be a bit tedious and confusing to figure out the interconnections with some gear. It's good to hear you got the radio and 'plotter connected and talking to each other.