NMEA2k backbone location

[ClarkGriswold]

This will be my first foray into a NMEA2k network on a boat. Wondering if there is a location you suggest for the first piece of the backbone as it relates to powering it? My first thought was under the helm and connected to a switch since that’s where a bulk of the connections will be located but open to other suggestions. In the future I would like to add the engine monitoring gateways so obviously will need a run from the ER as well.

 

[stg099]

I just setup my first network this off season and powered it under the helm as most connections were located there. With the center of the network there, I extended with backbone cables to the cabin and the ER for future expansion

 

[Stee6043]

+2 at the helm. It's where my power and switch is located. Located at the helm makes it easy to power on/power off the network when you're also likely doing the same with your MFD's, VHF, etc.

 

[RollerCoastr]

The put the power T near the middle of the device T’s.

When you’re just starting out, the backbone doesn’t even need to include an actual cable - it can be made up of only T’s and terminators. (think of it as a direction instead of an object. The backbone is the horizontal and the devices and power (drops) are vertical, or the backbone is the X axis and drops are the Y)

 

[ClarkGriswold]

The put the power T near the middle of the device T’s.

When you’re just starting out, the backbone doesn’t even need to include an actual cable - it can be made up of only T’s and terminators. (think of it as a direction instead of an object. The backbone is the horizontal and the devices and power (drops) are vertical, or the backbone is the X axis and drops are the Y)

Right on. Good info there. Thanks!

 

[Chris-380]

I powered mine from the “ELECT” switch on the helm, which worked out good.

 

[ClarkGriswold]

I powered mine from the “ELECT” switch on the helm, which worked out good.

Yeah, I was thinking of just using the AP switch on mine as we do not have AP.

 

[ttmott]

You will probably be OK for the size of the system to put the power tap anywhere. But to do it right you will want to balance the loads. Each NMEA 2000 device has a Load Equivalency Number (LEN) which is the amperage demand; that is provided in the documentation of the device. With that LEN data you can then locate the backbone tees for each device in conjunction with the power tap. Download the Maretron N2K Builder, it's free, and start your system design on that with thoughts on growth. The program has features to show voltage drop, current, and NMEA 2000 violations. Here is an example of the N2K Builder design output for my system (yellow are the power taps) -

 

[ClarkGriswold]

You will probably be OK for the size of the system to put the power tap anywhere. But to do it right you will want to balance the loads. Each NMEA 2000 device has a Load Equivalency Number (LEN) which is the amperage demand; that is provided in the documentation of the device. With that LEN data you can then locate the backbone tees for each device in conjunction with the power tap. Download the Maretron N2K Builder, it's free, and start your system design on that with thoughts on growth. The program has features to show voltage drop, current, and NMEA 2000 violations. Here is an example of the N2K Builder design output for my system (yellow are the power taps) -
View attachment 124422

Outstanding, thank you!

 

[mdolesh]

Following. Please take pictures and update us on your installation. I aim to do that same project one day.

 

[ClarkGriswold]

You will probably be underwhelmed as my electronics needs on the Upper Miss pale in comparison to those of you on the coasts and big lakes. I know my stretch of the river pretty well, but AIS would be SO helpful for timing lock arrivals. That's my #1 want/need aside from updated VHF and new transducer.

 

[ttmott]

You will probably be underwhelmed as my electronics needs on the Upper Miss pale in comparison to those of you on the coasts and big lakes. I know my stretch of the river pretty well, but AIS would be SO helpful for timing lock arrivals. That's my #1 want/need aside from updated VHF and new transducer.

I thought I'd throw this out there also if it helps - If all of your devices have a LEN of 0 then the network may not need a power tap. The devices have their own power supply and only use the data wires in the network. However, some devices that are self powered use the NMEA 2000 power to trigger data transmission but then some do not. For a simple system you may not need power - I'd set up a mock system at the house to find out. You can always add the power later.

 

[markrsimon]

You will probably be underwhelmed as my electronics needs on the Upper Miss pale in comparison to those of you on the coasts and big lakes. I know my stretch of the river pretty well, but AIS would be SO helpful for timing lock arrivals. That's my #1 want/need aside from updated VHF and new transducer.

I’ve never had to deal with locks yet - so I’m curious.. how does AIS help with locks? Is it so they know your heading that way and can be prepared? Or do the locks transmit AIS with info regarding next opening?

 

[ClarkGriswold]

Just timing to get there before a tow…or delay your departure if you can’t beat one to the lock. It can make 90-120min difference depending on if you get there before a tow or not.

I also like to see the traffic and be able to communicate with the tow if needed.

Im a river geek and come by it honestly.