Garmin 740s Network Connectivity

[SHASA III]

OK -- I've been searching the forum for specifics, to no avail.

I'm replacing my Garmin 740xs, on the bridge, with a Garmin 942xs. The 942xs has both the Garmin Marine Network port in addition to the NMEA 2000 port. My 740xs does not have the Garmin port, just the NMEA 2000 port.

I'd like to relocate the 740xs to the lower helm station, but I will need to see the depth reading from the transducer attached to the 942xs. Will that info be available via the NMEA 2000 bus or is it only available for units connected through the Garmin Network? I haven't received the 942 yet, nor have I installed the NMEA bus, until I know if I'm just spinning my wheels.

Anyone have experience with this specific situation?

Thanks.

 

[Bob Cofer]

I have networked 740S's (NMEA 2K) and can read depth on both units.

 

[Donsan]

My understanding is you can pass the numerical data (depth) on NMEA 2000 but not the video data from the sonar capability of the 942XS.

 

[rwidman]

Garmin tech support could probably answer your question best.

 

[SHASA III]

I appreciate the responses...Bob appears to have confirmed that the NMEA 2K network would meet my needs for the digital read-out; I wasn't interested the sonar video capability.

Yeah, I tried Tech Support, but gave up due the long wait times, on the phone. And, I'm guessing that there is more actual experience right here on this forum.

Once I get the 942xs, I'll bread-board a 2K network before I widen the opening in my lower helm panel. Presently, there is an old Datamarine Dart depth display in that spot, which the relocated 740 will replace.

Glad I'll be able to utilize the 740, rather than sell it at a fire sale price!

Thanks, guys.

 

[LarryM]

My understanding is you can pass the numerical data (depth) on NMEA 2000 but not the video data from the sonar capability of the 942XS.

That is correct. You can also synchronize/merge user data (waypoints and routes) between devices over N2K, but no radar or sonar video as the 7xx devices are stand-alone, and can only display the video data from devices connected directly to them, ie. radar and sounder.

 

[SHASA III]

Resurrecting this thread...

I recently installed antennas & cables for my Kenwood 2 Meter radio and a new Digital Yacht AIS, and yesterday I installed the NMEA 2000 network. The AIS is active on both the 942 & 740 chart plotters, and both Garmins can see each other on the network. The digital depth info from the 942 is not, however, visible on the 740. Since they can both see each other on the configuration page, connectivity is not an issue. So, it might not be possible to share data, as I hoped.

 

[LarryM]

Vic,

You definitely need to give Garmin a call on this one. The 740 is talking and listening on the N2K network, while the 942 is sharing sonar information over the Garmin network. This was a significant difference between the two generations. That said, I would have definitely thought the digital depth would be visible on the 740.

When I contacted Garmin a couple of months ago about connecting the two generations on the same N2K network, I was told that some of the 942's information was now communicated over the Garmin network so the 'synchronization' of data was not as 'tight' as between devices in the same generation. The Garmin network is faster etc.

Good luck

 

[O C Diver]

You could always add another transducer that connects to the N2K back bone. I have 2 depth transducers on my N2K network. You simply manually select which one you want each display to use.

Ted

 

[SHASA III]

Here's the response I received from Garmin. Looks like a no-go. Oh, well...maybe I can find a network transducer that also includes the speed feature, for the N2K bus.

I'd be happy to help. In the GPSMAP 740s go to Configure>Communications>Preferred Sources. Select the type of data then select data source. Unfortunately the two cannot share user data over NMEA 2000. To share data between the two, you will need to use an SD card.

Thank you for choosing Garmin,

Jeffrey

 

[LarryM]

Vic,

That being the case, why not just install a Garmin 010-10327-00, P79 6-pin plastic shoot thru-hull transducer connected directly to the sounder pigtail on the 740S. That way, you have a fully featured sonar and display on the 740S, and a redundant source of depth information. The 740s will also output the digital depth information over the N2K network.

They are not expensive and you won't have to make any more holes in the hull.

 

[Maerin]

When Garmin refers to "user data", that would mean routes, waypoints, marks etc. that are created via the user interface, would it not?

Depth is not user data, it's system data. It sounds like Garmin tech support is speaking geek, you're listening in ungeek. I'd get clarification and make sure you're on the same page. N2K data should flow between any N2K compatible devices. If each device has an N2K port, it's logical that any data on the N2K network would be available to any other device that's on the same network. That's the whole purpose of N2K. Depth is pretty basic standardized N2K/NMEA format; routes and waypoints tend to be proprietary formats, and that they're not shared on N2K is not remarkable, particularly considering Garmin's (or any other manufacturers') proprietary approach to that data. That's why you need software that's capable of formatting waypoint/route data before it can share it with a Garmin or nearly any other system that uses a proprietary format.

I think you need to go back to Garmin and have them clarify in easily understood terms what you are asking about, their reply doesn't make sense. My bet is that if it's N2K data, any device with an N2K port will see it and use if when the cable is plugged in. Persist.

 

[SHASA III]

I sent a reply back to Garmin...the menu item Jeffery mentioned does not appear on the 740xs configuration pages. I've also looked at all the menu items on the 942xs...nothing about sharing depth info on the network. So, I might have to add a network transducer, as previously noted, although I dislike the thru-hull units and would like to add one with a speed transducer. More boat units...

 

[SHASA III]

Last update...

After numerous email exchanges and diagnosing with Garmin support, I updated the 740s software to Ver. 4.3 and the 942xs to Ver. 8.7. Updating the 740s from 4.1 to 4.3 didn't do it -- the 942xs came from the factory with Ver. 8.6 -- the update to Ver 8.7 did the trick. The 740s now properly displays the digital depth info from the 942xs over the NMEA2000 bus.

Kudos to Tim, at Garmin support, for staying with this until a happy resolution...great support!