NMEA 2000 questions

[Boatagain]

I'm currently installing an AIS and it requires a connection to the N2K network. I don't know a lot about N2K so I have some questions:

Is it ok to connect to the end of the chain as opposed to using a T connector?

Any precautions concerning plugging and unplugging connectors? Does the network need to be shut-down when fiddling with the connectors?

Thanks in advance!

 

[Kevin Lamont]

I'm currently installing an AIS and it requires a connection to the N2K network. I don't know a lot about N2K so I have some questions:

Is it ok to connect to the end of the chain as opposed to using a T connector?

Any precautions concerning plugging and unplugging connectors? Does the network need to be shut-down when fiddling with the connectors?

Thanks in advance!

You can connect to the end of a chain (backbone) but you need a T connector as there always has to be a "terminator" at the end which is just a single dead end plug, if you dont you will have issues either in the future or right away. You will see it at the end of the backbone. Also depending on if you have a command bridge or not there would be a wire coming from one end headed up to the command bridge.

I always shut down all N2K components then turn the house and engine switches off, just as a precaution. Also when disconnecting and connecting connectors both sides spin so you do have to hold one and loosen/tighten the other, otherwise you will just get frustrated by it not coming apart. There is only one way they go together as it is keyed and there is a female and male end.

Hope this helps.

 

[Boatagain]

Thank you Kevin, that helps a lot!

 

[Kevin Lamont]

Your welcome, let us know if you have any more questions.

 

[Chimo]

Your welcome, let us know if you have any more questions.

Very Timely!

Background: Last month I updated the software on the Garmin GPSMAP 7610xsv on our 2017 R25SC without any apparent issues. Last week I was on day three of a trip and tried to use the Autoguidance for the next leg , something I had been doing regularly. The route was created as usual but the pop-up window to engage the autopilot was missing. On the autopilot screen there was no option to 'Follow route'. Obviously the two units had stopped talking. Fast forward to yesterday where after an hour or so on the phone with Garmin support (very helpful people) the autopilot tech. deduced that unit had got a bit confused (my words) during the software update. Apparently it's happened before. The solution, "Go to your NEMA 2000 backbone".

So: First question, on this boat where is the NEMA 2000 backbone located? I couldn't find it.

No problem, "Turn off your plotter and then turn off all your DC breakers. Turn off the DC master breaker." Did this only to find that the GC20 autopilot display is still powered. "Turn off your house battery." OK, that done the GC20 shut down. Waited the required 10 seconds and then powered everything back up. Result: Autoguidance working fine, happy customer 🙂 . If anyone else has this issue I hope the above may be helpful.

So: Second question, where's the best place to install a power switch for the NEMA 2000 backbone? Can it easily go through a spare 'Accessory' breaker on the DC panel? As the Garmin tech. pointed out, if the backbone is continuously powered and there's no shorepower available then all the sensors etc. are still draining the battery. A user may think he is only powering the fridge and calculate battery use on that basis alone but there's actually an additional, presumably small, load on the house batteries.

 

[Boatagain]

On my former boat, a 2014 R25SC, there was a dedicated breaker on the DC panel labeled NMEA 2000. Not so on yours?

 

[Chimo]

On my former boat, a 2014 R25SC, there was a dedicated breaker on the DC panel labeled NMEA 2000. Not so on yours?

Not so. I had all the breakers off and the autopilot was still powered, screen on.

 

[Chimo]

Should I be moving my questions to "Ask the factory?"

 

[Bruce Moore]

Should I be moving my questions to "Ask the factory?"

Ask the Factory forum posts are monitored by the factory. That's the best place if you want their attention on Tugnuts. Or, email or call the factory directly.

Cheers,

Bruce

 

[Kevin Lamont]

Your welcome, let us know if you have any more questions.

Very Timely!

Background: Last month I updated the software on the Garmin GPSMAP 7610xsv on our 2017 R25SC without any apparent issues. Last week I was on day three of a trip and tried to use the Autoguidance for the next leg , something I had been doing regularly. The route was created as usual but the pop-up window to engage the autopilot was missing. On the autopilot screen there was no option to 'Follow route'. Obviously the two units had stopped talking. Fast forward to yesterday where after an hour or so on the phone with Garmin support (very helpful people) the autopilot tech. deduced that unit had got a bit confused (my words) during the software update. Apparently it's happened before. The solution, "Go to your NEMA 2000 backbone".

So: First question, on this boat where is the NEMA 2000 backbone located? I couldn't find it.

No problem, "Turn off your plotter and then turn off all your DC breakers. Turn off the DC master breaker." Did this only to find that the GC20 autopilot display is still powered. "Turn off your house battery." OK, that done the GC20 shut down. Waited the required 10 seconds and then powered everything back up. Result: Autoguidance working fine, happy customer 🙂 . If anyone else has this issue I hope the above may be helpful.

So: Second question, where's the best place to install a power switch for the NEMA 2000 backbone? Can it easily go through a spare 'Accessory' breaker on the DC panel? As the Garmin tech. pointed out, if the backbone is continuously powered and there's no shorepower available then all the sensors etc. are still draining the battery. A user may think he is only powering the fridge and calculate battery use on that basis alone but there's actually an additional, presumably small, load on the house batteries.

Sorry for the delayed response, we are currently super busy!! Good problem to have.

The N2K backbone I believe is behind the fridge, there are four screws holding the fridge in, remove them and pull out the fridge. I always put a towel down so once out I can slide it around without scratching the floor. Once out you should be able to see it right there hanging down a bit. You should have one "T" with a yellow wire coming from it, that is your N2K power.

When the boat is not being used and not on shorepower I would always turn off all my battery switches. Also you can turn on/off the autopilot screen by pressing the power button on the panel, if you are worried about voltage loss. Not exactly sure why we no longer put the N2K power on a switch but we haven't had any issues without having it, I like the fact that it is one less thing to remember when leaving, also if the switch goes bad then you have no N2K power all together. I would recommend leaving it how its wired currently, we had a few where it was powered through the Fusion radio so if you don't have the yellow wire I am describing I would recommend wiring the N2K power direct to the dash fuse block. I have done a few of these now and fixes a lot of weird issues from Autopilot to not being able to control the Fusion radio (locked startup screen).

Let me know if you have any questions and I will try and get back to you asap.

 

[Chimo]

Hi Kevin. Thanks for the full response. I had actually shifted this to "Ask the factory" and got an answer from Andrew. (Don't worry, they match). You added good info. about removing the fridge and I may need to access the backbone at some other point to tie in another piece of equipment. You also mentioned the stereo and that was a good reminder of something I was told during orientation.

Much appreciated