One N2k network or two (Yanmar LY3 network)

[codingparadox]

Our new-to-us boat has 2008 electronics on it, including a complete lack of an N2k network with any sensors or anything on it. What it DOES have, is Yanmar LY3 diesels, which apparently use its own N2k network to communicate between the motors, the displays, and, most importantly/scarily, the throttles.

So it has this nice N2k network conveniently plumbed through the boat to the helm and both engine rooms. However, I'm scared that dumping all the other N2k goodies on that I want to, I risk introducing enough spam on the system that maybe, someday, it'll cause something to happen and I lose engine control, even if briefly.

What are best practices in this scenario? Just suck it up, run a second parallel info/sensor network, and bridge the info packets off the engine network to the main info network, so that I always know my motors work?

[codingparadox]

Just poking more around on this tonight. The Yanmar manuals definitely describe the engine network as "NMEA 2000", but reading up more on J1939, it seems a lot more likely that it's actually J1939. If that's the case, I could just use my Garmin chartplotter to bridge the J1939 network into a primary N2k sensor/info network.

[smac999]

I highly doubt the engines are using "nmea 2000" data. it's probably it's own can bus but using simular hardware.

[codingparadox]

That's what I thought! But the manual very clearly spells out NMEA 2000 several times for the backbone. Maybe they simply mean "NMEA 2000 parts but we're doing custom PGNs across it" or something like that. Haven't hooked up any analysis tools to the network yet to check PGNs, been too busy installing the internet setup.

Maybe I'll just hook up my little test box tomorrow and fire up the engines to log some packets and see what comes out...

[OS2Dude]

If the manual states it is NMEA2000 (especially multiple times) I would think it is. (NMEA2000 covers both hardware and software protocols.) That does not mean your network devices are not using proprietary PGNs. (That is the great thing about standards, there are so many versions of them. . .) I can't image NMEA would not have a gaggle of lawyers on a manufacture who claimed to be NMEA2K compliant but was not. (Mainly because they wouldn't be getting the license fees.)

NMEA2K is designed for multiple devices. I doubt you could build a network of compliant devices that could overload it.

[Glasshopper]

I'd be thinking robustness ;
In the interest of reducing RISK of damage from lightning strike i would keep this network separate
anything atop the mast.
Rob.