Garmin NMEA 2000 set up and two confused engineers

[[70521]]

I've finally got all of the bits for my new Garmin NMEA 2000 set up in place: the whirry thing is spinning round at the top of the mast; the lead is correctly attached to the plug; the plug is correctly connected to the black box and it is flashing green lights at us; the black box is connected to the backbone and is flashing green lights at us; the backbone has power and a wind instrument is connected and the set up menus have been gone through, BUT on the wind read out all we have is a set of dashes.

Is there anything that two rather confused and highly qualified engineers have missed?

And if anybody has any tricks for removing new VERY stiff through hull blanking plates I'd love to hear them as I'd quite like to get the water sensor in place. Three different people heaved and heaved, and closely avoided a hernia!

 

[knuterikt]

Make sure the threads on the blanking plug is completely disengaged.
You might need to select the source for wind data on your display.

 

[neil1967]

Is the NMEA2000 network otherwise complete? I added an AIS transceiver when on the hard a few years ago and tested it without powering up all the instruments, sensors, etc - it worked fine, but when I launched and powered everything up I found that some of the instruments, which had been getting their data from the chartplotter had auto selected the AIS as a data source - I had to go and manually change the sources. Come to think of it, that might have been the wind instruments. I think a methodical check through the settings and data sources might reveal the problem.

 

[david_bagshaw]

I have been helping out a club member, with his NMEA 2000, he was missing the resistors at each end of the backbone, and the network power connection was there physically, but not turned on!

 

[richardbrennan]

If you can dry the boat out, try tapping the blanking plate with a well padded hammer from underneath.

 

[pvb]

I've finally got all of the bits for my new Garmin NMEA 2000 set up in place: the whirry thing is spinning round at the top of the mast; the lead is correctly attached to the plug; the plug is correctly connected to the black box and it is flashing green lights at us; the black box is connected to the backbone and is flashing green lights at us; the backbone has power and a wind instrument is connected and the set up menus have been gone through, BUT on the wind read out all we have is a set of dashes.

Is there anything that two rather confused and highly qualified engineers have missed?

It would be useful if you said which specific devices you have in the network. When you say "wind read out" are you talking about an instrument head or a field on the plotter screen?

And if anybody has any tricks for removing new VERY stiff through hull blanking plates I'd love to hear them as I'd quite like to get the water sensor in place. Three different people heaved and heaved, and closely avoided a hernia!

You should always smear the O-rings with silicone grease before fitting either the transducer or the blanking plug. As knuterikt said, you need to ensure the threaded collar is completely unscrewed (it usually "jacks up" the plug slightly). You can grip the top of the plug with adjustable pliers and wiggle it to help free it.

 

[ghostlymoron]

Your two engineers are obviously well qualified in the wrong branch of engineering. I'm a chartered civil and structural engineering but it doesn't help with marine electronics!

 

[ghostlymoron]

Your two engineers are obviously well qualified in the wrong branch of engineering. I'm a chartered civil and structural engineer but it doesn't help with marine electronics!

 

[[70521]]

Make sure the threads on the blanking plug is completely disengaged.
You might need to select the source for wind data on your display.

Thanks knuterikt, I can confirm that the threads were completely disengaged and we could pull the blanking plug about 20 mm. The instrument was set to auto but I'll have play with the settings.

Is the NMEA2000 network otherwise complete? I added an AIS transceiver when on the hard a few years ago and tested it without powering up all the instruments, sensors, etc - it worked fine, but when I launched and powered everything up I found that some of the instruments, which had been getting their data from the chartplotter had auto selected the AIS as a data source - I had to go and manually change the sources. Come to think of it, that might have been the wind instruments. I think a methodical check through the settings and data sources might reveal the problem.

Thanks Neil, all that we have on at the moment is the wind sensor and one instrument, the backbone is set up with power and the two end resistors.

I have been helping out a club member, with his NMEA 2000, he was missing the resistors at each end of the backbone, and the network power connection was there physically, but not turned on!

Cheers David, resistors are in.

If you can dry the boat out, try tapping the blanking plate with a well padded hammer from underneath.

Cheers Ricard, we are rapidly coming to that conclusion

It would be useful if you said which specific devices you have in the network. When you say "wind read out" are you talking about an instrument head or a field on the plotter screen?

You should always smear the O-rings with silicone grease before fitting either the transducer or the blanking plug. As knuterikt said, you need to ensure the threaded collar is completely unscrewed (it usually "jacks up" the plug slightly). You can grip the top of the plug with adjustable pliers and wiggle it to help free it.

Its just the wind instrument head, the plotter will be added in later once we have the system up and running

Your two engineers are obviously well qualified in the wrong branch of engineering. I'm a chartered civil and structural engineer but it doesn't help with marine electronics!

ghostlymoron, to our embarrassment my first degree has an extremely high amount of electronic engineering including CAN networks and my crew member has a PhD in electronics, so we were hoping that the skill mix was about right.

Thanks all for your comments, I am sure we will get it sorted when we get down to the boat again and can spent more time with the configuration and have done some research on the web.

 

[mlines]

Is the NMEA2000 power budget correct?

 

[[70521]]

Is the NMEA2000 power budget correct?

Can you expand what you mean mlines? The network is set up exactly as specified in the manual.

 

[cobolt]

He means if you have too many NMEA2K devices on the network (too high LEN ratings), then the power available to devices towards either "end" of the network might be too low and prevent those devices working properly.

Can be managed by having an additional power insertion point if required...sounds like your network is quite small though so can't imagine it is the issue.

 

[[70521]]

He means if you have too many NMEA2K devices on the network (too high LEN ratings), then the power available to devices towards either "end" of the network might be too low and prevent those devices working properly.

Can be managed by having an additional power insertion point if required...sounds like your network is quite small though so can't imagine it is the issue.

Currently, we have the wind sensor and one display. The final configuration will have wind and water sensors, wind and water display instruments plus a chart plotter. Should be well within the "power budget", length of runs are well under 10 meters.

 

[cobolt]

Yes, won't be that then.

Is it the wired Gwind you have at masthead, wired down to a GND10 conversion box that is connected to the N2K bus?

If so, do you see not only green flashing lights to indicate the GND10 box is working on the bus, but also very small flashing light next to the plug/socket where your masthead sensor is connected into the box?

We have same set up, and the plug from masthead needs to be very firmly pushed into the socket, and the collar tightened down, otherwise it looks and feels connected but there is no data coming from masthead to the GND10 box.

 

[skipmac]

Not sure if Garmin is the same but in my mixed manufacturer network (Garmin plotter, Raymarine speed/depth, B&G AP/compass/heading/wind) the B&G wind, I think due to the length of the cable, replaces the terminator resistor on one end of the backbone.

 

[cobolt]

Not sure if Garmin is the same but in my mixed manufacturer network (Garmin plotter, Raymarine speed/depth, B&G AP/compass/heading/wind) the B&G wind, I think due to the length of the cable, replaces the terminator resistor on one end of the backbone.

No it's different in this case, the GND10 conversion box is the NMEA2K network element. The Wind transducer is essentially a re-branded piece of NEXUS gear, with the GND10 acting as a NMEA2K translator, so the transducer is not considered part of the N2K network itself.

 

[[70521]]

Yes, won't be that then.

Is it the wired Gwind you have at masthead, wired down to a GND10 conversion box that is connected to the N2K bus?

If so, do you see not only green flashing lights to indicate the GND10 box is working on the bus, but also very small flashing light next to the plug/socket where your masthead sensor is connected into the box?

We have same set up, and the plug from masthead needs to be very firmly pushed into the socket, and the collar tightened down, otherwise it looks and feels connected but there is no data coming from masthead to the GND10 box.

Thanks colbot, that makes sense, we have not screwed things down tightly, as we are just testing at the moment.

Both wee green LEDs are flashing happily.

 

[Moonbeam]

Did you get this sorted out?

If you have no GPS connected to the NMEA 2000 network (as you seem to indicate in your original post) and your wind display is showing 'true' wind speed, it will not show any data. It will if you toggle the wind speed to 'apparent'. This also happens even if you have a GPS connected, but you are not moving (GPS has no speed to calculate true wind speed)

 

[[70521]]

Did you get this sorted out?

If you have no GPS connected to the NMEA 2000 network (as you seem to indicate in your original post) and your wind display is showing 'true' wind speed, it will not show any data. It will if you toggle the wind speed to 'apparent'. This also happens even if you have a GPS connected, but you are not moving (GPS has no speed to calculate true wind speed)

Thanks Telstarr

Popped down to the boat at the weekend and all sorted, after sitting quietly and working through the system. A small issue of some connectors.

I am looking forward to seeing true wind, saves doing some sums.

 

[Moonbeam]

Thanks Telstarr

Popped down to the boat at the weekend and all sorted, after sitting quietly and working through the system. A small issue of some connectors.

I am looking forward to seeing true wind, saves doing some sums.

Glad you have it all working. Amazing what taking a break and then looking at something afresh can achieve.