NMEA2000/Maretron Powertap Connection

[colemj]

Originally Posted by delmarrey

That would be fun.

I may just settle for the in-line tee's with terminators...........

The mast is already back on the boat.

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You can't use the mast cable as a drop cable on the network. It is too long. No way around it - you will have to terminate the end of that cable.

Mark

[Lake-Effect]

Slight derail - if you're working with an N2K system, or even just contemplating one for your boat, get Maretron's free N2KBuilder software. It's very useful for planning the network and getting the terminations right. Also, it's cool.

This system seems it was designed to be installed by a contractor with a huge inventory in a van that could be drawn from, and charged out for labor and parts. Anyone want to start a business?

Um, yup I'm working part-time for a busy marine electrician and one of the projects is a complete Maretron/Furuno system (instruments, autopilot, radar) in a lovely old cutter. The total job is over $30k. Job was recently held up for over a week because a local distributor didn't stock the necessary part, but wouldn't expedite either.

(Hey manufacturers/distributors, if you want us to sell and install $70 cables, the least you could do is have stock... )

[goboatingnow]

If its one device just connected to the other , just connect them together. You don't actually need the tees, if you need termination add it later ( solder in 1-2 120 ohm resistors. )
Can bus is much more topology tolerant then the specs suggest.

I have a can A device connected to a can B device with just 30m twisted cable on the bench


The purpose of the termination resistors is to prevent ringing ( ie under /over shoot ) due to the inductance of the long cable. However most modern driver ICs are fairly tolerant ( check your data rate errors )

With two devices there's F -all collisions going on Anyway.

Power can be injected using a snips and a soldering iron if you feel so inclined.

Pick up a good can bus book for background info

Dave

[colemj]

Originally Posted by goboatingnow

If its one device just connected to the other , just connect them together. You don't actually need the tees, if you need termination add it later ( solder in 1-2 120 ohm resistors. )
Can bus is much more topology tolerant then the specs suggest.

How are the devices to be powered that way? You can't just connect them together without also supplying power someway.

Mark

[Lake-Effect]

Originally Posted by goboatingnow

If its one device just connected to the other , just connect them together. You don't actually need the tees, if you need termination add it later ( solder in 1-2 120 ohm resistors. )
Can bus is much more topology tolerant then the specs suggest.

...

Power can be injected using a snips and a soldering iron if you feel so inclined.

woo, that sounds dangerously close to hacking to me.

The main arguments for doing the N2K network 'by the book' with the official hardware are:
- expandability: official connectors make it much easier to add/replace tees and other devices at a later date. The bigger the network, the more important proper termination becomes
- serviceability: if you have a home-spliced, improperly-terminated network and then have problems down the road, few serviceman will touch it. They can't even couple their network analyzer (assuming they have one) to the system without having to cut one of their precious cables and clip in.

[delmarrey]

Originally Posted by Lake-Effect

Slight derail - if you're working with an N2K system, or even just contemplating one for your boat, get Maretron's free N2KBuilder software. It's very useful for planning the network and getting the terminations right. Also, it's cool.

Originally Posted by Maretron

N2KBuilder™ software is a powerful, free PC-based tool for designing and verifying the integrity of NMEA 2000® networks. The N2KBuilder™ software, when installed on a Windows PC

I woulda if I coulda. But I run Mac and don't have access to PC anymore (work).

Anyway, I called the man himself and he tells me it's what Mark suggested;

Originally Posted by colemj

DSM150 -> inline terminator -> powertap -> inline terminator ->WSO100

The terminators are ~$16 and the powertap ~$36. The cables will depend on how far apart you want things.

The powertap has two wires that go to +12V and three that go to -12V. It is this way so it can supply power down both sides of the trunk.

Mark

The parts are coming and I just need to break out the rock climbing gear for this one.
Thanks for all the help!


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