NMEA 4 way T

[Saltyone]

Starting to build my network, was curious if you can connect two 4-way NMEA connectors directly together? Tried google searching, but havent found anything with my searches

If so, I assume just make the power connection in one of the center 2 ports?

Thanks

 

[wspitler]

The simple answer is yes. It does not matter where you place the power onto the Nema bus. There are limitations on the length of runs but they are typically not an issue for our size boats. You can actually place T (drop down) connectors in various places by running lines between them so they do not have to be connected directly in series. Both ends of the bus require terminating resistors.

 

[SkunkBoat]

Starting to build my network, was curious if you can connect two 4-way NMEA connectors directly together? Tried google searching, but havent found anything with my searches

If so, I assume just make the power connection in one of the center 2 ports?

Thanks

Connecting two 4 way together directly to get 8 ports all right next to each other? with a male and female terminator on the backbone(yellow) ends and on any unused ports? Not realistic.

You will need to separate them with a backbone cable because you need to isolate the Suzuki Gauge N2k power from the house powered N2k. There is a special backbone N2k power isolator connector. It passes the data but not the 12v power.

You need 2 power isolated ports for the gauges and a port for the keyed power feed. The motors will share data over the N2k but power up with the key.

You probably need ports up in the hardtop. Better to send a single backbone up there than multiple drop cables.

So, Power is connected on any drop port but...you need two separate power feeds.


here's some pix of mine.

 

[Saltyone]

Thanks Skunk

 

[Saltyone]

So when I explained this setup to the installer, he mentioned the 2 power T's aren't necessary. That the gauges don't get their power from the NMEA network. So he wired it basically the same as you, but only the single house T. He left the isolator in there though?

The MFDs power up with the key, but I'm not seeing any engine data displayed on the MFDs, so I'm wondering if it's because he didn't put the ignition power T in there?

 

[SkunkBoat]

So when I explained this setup to the installer, he mentioned the 2 power T's aren't necessary. That the gauges don't get their power from the NMEA network. So he wired it basically the same as you, but only the single house T. He left the isolator in there though?

The MFDs power up with the key, but I'm not seeing any engine data displayed on the MFDs, so I'm wondering if it's because he didn't put the ignition power T in there?

Need some clarification...
MFDs? You mean the gauges or your Raymarine MFD? The motors are on and he gave you back the boat and you run the motors and don't see engine data?
That can't be right...


I can't find the diagram I'm looking for that shows the isolator and separate power for the "Keyed" side and the "House" side. I know there is one on the web but I can't find it.

This is a Suzuki diagram that shows only what you get from Suzuki assuming you have no other electronics. Notice there is a power T with NMEA Power connected. That power is keyed by the Suzuki switch.
The 2 Multi gauges are connected to the NMEA backbone using drops. They include a GPS puck so the gauge can display speed and calculate mpg.
This is the minimum setup for the gauges to give you everything.
The gauges might work without N2Kpower but you would not get any mpg or speed.
I don't know if the gauges will be recognized on the network or output data to the network without a power T on their side of the isolator. idk.

In my setup there is no GPS puck because there are already multiple gps sources on the rest of my network.
My network isolates the gauge side power from the rest of the network because I don't want to need the key on to use the electronics AND
I don't want the gauges to be powered unless the key is on. FYI, the fuel pumps run when the key is on.
You COULD connect everything to this setup without an isolator and everything would require the key to be on.


To understand what my setup is like, look at the diagram below. Substitute an isolator where #10 is and connect a backbone to the rest of your network, powered by a T with House power.
I switch off my House power before leaving the boat. Thats important. You don't want to leave the N2K network powered as it could run down batteries over a long time (days/weeks).

 

[Saltyone]

Need some clarification...
MFDs? You mean the gauges or your Raymarine MFD? The motors are on and he gave you back the boat and you run the motors and don't see engine data?
That can't be right...


I can't find the diagram I'm looking for that shows the isolator and separate power for the "Keyed" side and the "House" side. I know there is one on the web but I can't find it.

This is a Suzuki diagram that shows only what you get from Suzuki assuming you have no other electronics. Notice there is a power T with NMEA Power connected. That power is keyed by the Suzuki switch.
The 2 Multi gauges are connected to the NMEA backbone using drops. They include a GPS puck so the gauge can display speed and calculate mpg.
This is the minimum setup for the gauges to give you everything.
The gauges might work without N2Kpower but you would not get any mpg or speed.
I don't know if the gauges will be recognized on the network or output data to the network without a power T on their side of the isolator. idk.

In my setup there is no GPS puck because there are already multiple gps sources on the rest of my network.
My network isolates the gauge side power from the rest of the network because I don't want to need the key on to use the electronics AND
I don't want the gauges to be powered unless the key is on. FYI, the fuel pumps run when the key is on.
You COULD connect everything to this setup without an isolator and everything would require the key to be on.


To understand what my setup is like, look at the diagram below. Substitute an isolator where #10 is and connect a backbone to the rest of your network, powered by a T with House power.
I switch off my House power before leaving the boat. Thats important. You don't want to leave the N2K network powered as it could run down batteries over a long time (days/weeks).




View attachment 28276

The suzuki gauges display engine data, but the Raymarine displays don't. I'm going to install the Keyed power T and see if anything changes.

 

[SkunkBoat]

By engine data you mean Tach, trim, Fuel Tank Levels (This is put on the N2k by the gauges if the fuel senders are connected to the Suzuki harness)?

On N2K not all engine data is in the "Engine Parameters" PGN on the network. You won't see error codes and oil pressure and things like that. Its not like having J1939 engine data

 

[Saltyone]

By engine data you mean Tach, trim, Fuel Tank Levels (This is put on the N2k by the gauges if the fuel senders are connected to the Suzuki harness)?

On N2K not all engine data is in the "Engine Parameters" PGN on the network. You won't see error codes and oil pressure and things like that. Its not like having J1939 engine data

Yeah, i dont see any of that. The fuel senders are connected, as i can see the level on the suzuki gauges.

 

[Saltyone]

Also when I go into the "Display Network" on the Raymarines, I see both Raymarine displays on the network, but dont see the Suzuki gauges

 

[SkunkBoat]

hehehe I was just going to ask if you see the gauges on the network.

I would connect the keyed N2k power using a power T. Make sure the zuke stuff is on one side of the isolator and the rest of the network on the other.

 

[SkunkBoat]

It might be that the N2k circuitry inside the gauges does not work without n2k power. That would kind of make sense.

 

[Saltyone]

It might be that the N2k circuitry inside the gauges does not work without n2k power. That would kind of make sense.

yeah, that does make sense. I'll get that wired in and see what happens. It looks like from the wiring diagram I've found there is a gray wire I can use for Ignition power.

 

[SkunkBoat]

Yes, there is a Gray & Black pair labeled specifically for N2k power. They have bullet connectors. The diagram doesn't show it but there should be a fuse on the Power T red wire. Put a male bullet on that and a female on the black.

 

[wspitler]

Yeah, i dont see any of that. The fuel senders are connected, as i can see the level on the suzuki gauges.

For my Yamaha‘s, all of that data is in fact on N2K. The software in the Garmin can pick it all up and it does not need to be a J 1939. The Garmins will display essentially all data. I initially had 2006 F250 and Garmin 5212s and now 2022 F300s and Garmin 1243s. It is a CAN bus to N2K. I am not familiar with the data produced by Suzukis so it could be different.

 

[Saltyone]

Yes, there is a Gray & Black pair labeled specifically for N2k power. They have bullet connectors. The diagram doesn't show it but there should be a fuse on the Power T red wire. Put a male bullet on that and a female on the black.

The gray and black are on the back side of the ignition switch correct?

 

[SkunkBoat]

The gray and black are on the back side of the ignition switch correct?

no. In the wire harness from the motors. They are tagged NMEA PWR

 

[Saltyone]

It's wired with the NMEA pwr from the suzuki harness and now I can see data on the Raymarine displays.