Topic: Helix 10 CHIRP MEGA DI+ G3N GPS to NMEA2000 (newly updated)

[jolebra]

This matter might need someone with insight of previous experience of a direct connection to a NMEA2000 backbone with exactly the same head from Humminbird without using its Ethernet port. The goal is to have AIS information on the head, coming from the Garmin 215i AIS already connected to the NMEA2000 backbone. Any comments or clarification on this and below would be greatly appreciated!

Everywhere I look at, there's info that we need an AS ETH NMEA2K - NMEA 2000 Black Box Adapter and an AS EC QDE cable to connect one side to the Ethernet port in the head and the other to the Black Box Adapter. Then, the adapter brings with it a common micro NMEA2000 5 pin drop cable to connect to a NMEA2000 T in a backbone.

However, a country technical representative of Humminbird I phoned to (not the UK Humminbird people), said between a number of comments, that there's no difference in what regards NMEA2000 connectivity between the Helix 10 CHIRP MEGA DI+ G3N GPS and the Helix 10 CHIRP MEGA DI+ G4N GPS. This statement either is untrue or there's a catch that is escaping me and maybe other users. The guy didn't want to explain anything more, just told me to go to the local Humminbird reseller in the country where the boat is moored, which of course, will request a payment just to look at the boat's wiring. What I know is that the G4N already has a NMEA2000 port with 5 female pins, while the G3N as what seems to be a similar port, but it just has 4 female pins and not the center one. If I'm right, the center pin in a 5 pin NEMA2000 backbone is used for the screen (shield) or is even not connected in some pin-outs visible in the web. Maybe the guy is right, and the trick we need to make is done by eliminating the center pin from the Humminbird 720114-1 Helix G4N NMEA2000 drop cable. And connect it to the G3N 4-pin port that looks de same as in the G4N except for the center pin as said.

Something is telling me that the country technical representative either knows nothing about the two (G3N and G4N) heads' NMEA2000 connection requirements or he is right and there's a simpler (and a lot cheaper) way of connecting this G3N to a NMEA2000 backbone. Otherwise the expensive black box and the QDE cable need to be used. Its an 'investment' that will be to me like taking a teeth off.

Any help or comments please, anybody?

[oschi]

G3N and less exchange NMEA2000 data over the ethernet port.
Ethernet uses twisted pair cable for rx/tx - NMEA2000 too. But slightly different. Especially the protocol that they are speaking. Therefore you need that cable which will convert ethernet layer/protocol to CAN-Bus equivalent, which NMEA2000 is using as physical layer.
The G4N has that CAN-Bus connectivity already build in as separate connector.
The 4-pin connector you mentioned is for the external speed & temp sensor HB offers. Nothing else.

[jolebra]

Hi Oschi, many thanks for your reply with the precise information that I needed regarding the NMEA2000 in a G3N.

It looks like won't escape the need for the AS QDE cable and the AS Eth to NMEA2000 black box. What an expense!

May I ask please if you can confirm that once the G3N head is connected to the NMEA2000 backbone, will I have AIS indications of every vessel sending its AIS data that would be in the VHF reception range displayed on the chart (e.g. in the Birds Eye View) that the already connected to the backbone Garmin VHF 215i AIS can provide?

[jolebra]

Ok, after Oschi's reply which was quite an eye opener, the conclusions were:
- The NMEA2K Black box provides input NMEA 2000 for engine data from a NMEA2000 backbone, provided you've got engine data arriving as output to the NMEA2000 backbone. Apparently the G3N can't input anything else, e.g. AIS data through the NMEA2K Black Box.

- The Communications Port of the Helix is a rectangle with one of the corners angled instead, and has 4 connectors. Their pin-out is down.

- To connect the Communications Port of an Helix, G3N we need an  AS NMEA 12 cable Humminbird ref. 720093-1.

Connections between G3N  AS NMEA 12 and a VHF Garmin 215i AIS can be done as in the attached picture. I used good old shielded RS-232 computer cable from my junk box.