NMEA 2000 network

[Flyer5]

I need to have a long run from my engine room to my Garmin on the fly bridge. I assume I have to do it as a backbone cable. So am I correct that I can run it this way?

 

[ttmott]

I need to have a long run from my engine room to my Garmin on the fly bridge. I assume I have to do it as a backbone cable. So am I correct that I can run it this way?View attachment 151950

Perfect except for maybe cable length. Need to verify Load Equivalent Numbers on all of the devices to make sure you have enough juice (if you need it) at the other end from the power tap. If the Echomap has a LEN of 0 then you'll probably be ok until other devices are added.

 

[Flyer5]

Perfect except for maybe cable length. Need to verify Load Equivalent Numbers on all of the devices to make sure you have enough juice (if you need it) at the other end from the power tap. If the Echomap has a LEN of 0 then you'll probably be ok until other devices are added.

Would I be better off putting the 12v pwr at the tee closest to the garmin by adding another tee or possibly both ends? The backbone cable is the heavy wire.

 

[ttmott]

Would I be better off putting the 12v pwr at the tee closest to the garmin by adding another tee or possibly both ends? The backbone cable is the heavy wire.

Nah - you need to analyze using the LEN of each device. Everything that connects to a NMEA2000 network will have a LEN. I suspect the LEN of the Garmin will be zero so the power tap where you have it should be OK. But adding anything to the system may create issues - that is a long backbone.
Download Maretron's N2KBuilder and model your system there - it is free to download and use. Then save it and as you add devices modify the model. N2KBuilder will do the analysis for the system and let you know.

 

[Skybolt]

Would I be better off putting the 12v pwr at the tee closest to the garmin by adding another tee or possibly both ends? The backbone cable is the heavy wire.

Assuming your backbone isn't 20' long, it doesn't matter where it is powered, middle or either end, but NEVER more then one power input per segment. I use segment because I power mine in many places, but also use power block(s) to do so. They keep the backbone connected at all time, but keep the power to that segment that they control. Most if not all NMEA2000 device have a minimum of 1 len(50ma), that is used to power the devices network controller.

The Garmin GMI 20 is 6 len, the 1243 is 2 len, the 7608 is 2 len. Things that are separately powered from the N2K network are usually 2 len or 75ma.

 

[Flyer5]

Assuming your backbone isn't 20' long, it doesn't matter where it is powered, middle or either end, but NEVER more then one power input per segment. I use segment because I power mine in many places, but also use power block(s) to do so. They keep the backbone connected at all time, but keep the power to that segment that they control. Most if not all NMEA2000 device have a minimum of 1 len(50ma), that is used to power the devices network controller.

The Garmin GMI 20 is 6 len, the 1243 is 2 len, the 7608 is 2 len. Things that are separately powered from the N2K network are usually 2 len or 75ma.

Backbone is 32'

 

[Flyer5]

Nah - you need to analyze using the LEN of each device. Everything that connects to a NMEA2000 network will have a LEN. I suspect the LEN of the Garmin will be zero so the power tap where you have it should be OK. But adding anything to the system may create issues - that is a long backbone.
Download Maretron's N2KBuilder and model your system there - it is free to download and use. Then save it and as you add devices modify the model. N2KBuilder will do the analysis for the system and let you know.

Can't route it any other way unfortunately.

 

[Skybolt]

Backbone is 32'

Depending on how much is on it, that shouldn't be an issue. But if things can be segmented then that would be best. Still can't power one segment with more then one power input.

 

[ttmott]

GARMIN LEN data - https://support.garmin.com/en-US/?faq=2iIFYCV2zM7b0gCOxCfXq8

 

[Skybolt]

Here are the cable/device limitations published by Garmin: https://www8.garmin.com/manuals/web...UID-D30B8240-E352-4F53-89CD-3E7DFD78FCAF.html

 

[Stee6043]

I ran a 10m backbone from my helm to the engine room, powered at the helm, zero issues. At the helm I have two plotters and a VHF radio connected. In the engine room I have two Fox gateways connected. One power tap, good to go.

 

[Flyer5]

As a follow up this layout was a success. Thank you