N2K device drop outs and Maretron Multiports

[Wdeertz]

I am having intermittent drop outs with two Yacht Devices unit (YDWG-02 WiFi gateway and YDEG-04 J1939 gateway) on my N2K network. The WiFi gateway drops out way more frequently than the J1939 gateway but the persistent problem is annoying. I’ve been working with the Yacht Devices technical support to try and rectify these drop outs. I sent technical support my N2K network schematic which I put together using the Maretron tool. They indicated that the multiport device is not in accordance with the N2K standard.

I have several Maretron multiport’s on my network and it’s only these 2 devices which are causing me grief. No drop is over 6m and the cumulative total is less than 78m, all connections are tight, good power, properly terminated. I ran my Maretron network meter and everything checks out ok, except occasionally my network utilization will go above 90% as I have a lot of devices.

I’ve reached out to Maretron technical support on the multiport device but haven’t heard back. Does anyone know if the multiport device is electrically equivalent to having each device on its own tee?

 

[wkearney99]

90%? Might be worth looking into separating out what's causing so much traffic. It's not like "all" of your devices on the network need to hear everything. A bridge between N2K segments could be configured to pass only what's needed on either side.

 

[bkcorwin]

I've been warned by several people that I should avoid yacht devices products as they have all seen various compatibility issues with their products. It may be that the yacht devices parts are causing the trouble.

Brian

 

[wkearney99]

I have several YD interfaces and have had zero problems with them.

I did, however, stop using the WiFi interface as there are more complex networking issues to consider and didn't find their unit up to my requirements.

 

[twistedtree]

I don't think the Maretron expanders are the problem, and they are allowed in N2K. But you could eliminate it as an excuse by at least temporarily plugging those devices directly into backbone Tee connections.

 

[Wdeertz]

90%? Might be worth looking into separating out what's causing so much traffic. It's not like "all" of your devices on the network need to hear everything. A bridge between N2K segments could be configured to pass only what's needed on either side.

Thanks for the input. At your suggestion I deep drilled into my N2K data stream and discovered I had 5 devices sending rapid position updates and rapid heading updates every 100ms. Needless to say this was bogging down the network. I eliminated 3 of these data streams and now my network utilization is peaking at 50%. I’m going to attribute the intermittent yacht device drop outs due to them being unable to handle the high network load. I won’t know for sure until my next long run as the J1939 wouldn’t usually drop out until 2-3 hours underway.

 

[wkearney99]

The network uses collision avoidance so in the more traffic you have blasting away at it the more trouble you'll have with messages trying to get through.

I find with any kind of networking the best plan is strict configuration that limits what can be sent. And consumers of the data the being configured to use only specific sources. Configure everything so that nothing is left to chance.

There's a temptation to use multiple active devices as some sort of redundancy scheme. This is not a great plan.. This isn't to say you shouldn't have multiple devices on board that could be used. Rather backup things should be configured to only be brought online because of failures. Letting them all shout their messages all the time is what gets you into the trouble you've got.

And for situations that genuinely need nonstop redundancy, you'd really have to use separate networks and bridges with configurations designed designed to be brought into play when failures occur. And this isn't going to happen with recreational grade equipment.

 

[Wdeertz]

The network uses collision avoidance so in the more traffic you have blasting away at it the more trouble you'll have with messages trying to get through.

I find with any kind of networking the best plan is strict configuration that limits what can be sent. And consumers of the data the being configured to use only specific sources. Configure everything so that nothing is left to chance.

There's a temptation to use multiple active devices as some sort of redundancy scheme. This is not a great plan.. This isn't to say you shouldn't have multiple devices on board that could be used. Rather backup things should be configured to only be brought online because of failures. Letting them all shout their messages all the time is what gets you into the trouble you've got.

And for situations that genuinely need nonstop redundancy, you'd really have to use separate networks and bridges with configurations designed designed to be brought into play when failures occur. And this isn't going to happen with recreational grade equipment.

Agree, I’ve disconnected redundant devices from the network to lessen network load. Now I need to figure out how to disable PGN’s on my airmar weather station that overlap with my SCX20 satellite compass.