Cerbo gx crashing garmin network

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screwdriversteve asked Jun 22, '24

Cerbo gx crashing garmin network

Hello all

I've been struggling for some time now trying to get my GX device connected to my Garmin Network. I think I have read all of the other posts around this question so forgive me if I miss the answer in another thread. If I plug my GX device into my Marine Network I can see it on one helm and everything appears to be working fine. I can see the GX device on active captain connected to the Wi-Fi on the boat as well as when I connect to the Garmin Wi-Fi. When I power down the Garmin equipment after leaving the boat and return the system will not boot up and I get a Garmin Network recovery screen. I have to power down the system disconnect the GX device and boot it back up to get it to work.

I have 3x 8600 series displays along with one 7-in display networked together. Using both the Garmin Network and nmea2000.

connected to the GX device

- Quattro inverter charger

- 2 victron solar controllers

- Smart shunt

- NMEA2000 Network

The GX device is connected to the Wi-Fi network on the boat and is communicating out onto the internet just fine. I have tried this configuration using the Garmin Poe isolator and the results are the same. I have a little bit of network experience but this level of troubleshooting is beyond me. It seems to be that there is a conflict in how the network addressing is being done when the system is booted.

When the GX device is independent from the Garmin Network both Networks perform flawlessly.

Any assistance would be greatly appreciated

cerbo gx marine mfd app garmin

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mvader (Victron Energy) answered · Jul 01 at 03:08 PM

Hi,

We spoke to Garmin Support:

The recovery loader typically is shown if pin 4, 5, 7 and 8 of the Ethernet cable are used.

Garmin uses these pins for internal purposes. The PoE isolator terminates those pins. Could you double check if those pins are used?

Or perhaps the cable is not properly crimped? At least if you are using self made cables.

Have you also tried to replace the cable from the GX to the Garmin network?

https://www.garmin.com/en-US/p/782081/pn/010-10580-10

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Answer 1 · 2024-06-22T18:52:12Z

mvader (Victron Energy) answered · Jun 22 at 06:52 PM

Hi,

That must be annoying!

Though I’m not a Garmin networking expert - I don’t know what could cause them to not boot, and haven’t heard about this issue before, herewith some tips and ideas that might help someone with more Garmin experience to sort this out with you.

I checked our notes, and last time we checked, the Garmins run their own DHCP server. Meaning that it should not be in a network with its own DHCP server: are you really connecting only the Cerbo into the network? Or is there then also a router connected (with dhcp service).

Perhaps a drawing helps.

And can you share screenshots or photos of the Ethernet menu page in the Cerbo, both when working OK and when not working OK; as well as a photo of the error on the Garmins. Does it give any details?

Ps. GX devices do not have a built in DHCP server.

6

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screwdriversteve commented · Jun 30 at 03:44 PM

Hello Mvader

I replied a couple of days ago but I see my comment didn't stick. Apologies I knew to the layout and hopefully this one sticks around. Your idea of DHCP made me think my GX device is connected to my starlink via Wi-Fi so I'm wondering if the GX is bridging the networks and the DHCP server in the starlink is fighting with the Garmin. I shut down the starlink and was able to repeat the error. So this is not the issue.

When the error occurs the GX shows the ethernet as unplugged so it's not even getting any messaging at all. It's like the Garmin unit completely misses booting it's OS and is sitting at a before the OS is loaded.

This is the GX ethernet screen when I plug it in after the Garmin has been booted and everything functions.

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mvader (Victron Energy) ♦♦ screwdriversteve commented · Jun 30 at 06:08 PM

Hey, thanks at helps.

The GX doesn’t do any network bridging. It looks to me like the GX inadvertedly sends some message causing the Garmin to think a recovery is wanted.

I’ll post this link to our Garmin contacts and see what they think.

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mvader (Victron Energy) ♦♦ mvader (Victron Energy) ♦♦ commented · Jun 30 at 06:09 PM

One more question, can you post a drawing of how it is all connected?

Picture of pencil drawing also helps.

Include the gx, all garmin equipment connected in ethernet, ethernet, wifi, starlink, anything else related.

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mvader (Victron Energy) ♦♦ mvader (Victron Energy) ♦♦ commented · Jun 30 at 06:15 PM

And have you already searched the internet? I found this:

https://support.garmin.com/en-US/?faq=r05l5kMTHn8nt03GhO3XY8

And this: https://community.victronenergy.com/questions/58725/cerbo-gx-and-garmin-8617-via-garmin-gms-10.html

(Unsolved)

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screwdriversteve mvader (Victron Energy) ♦♦ commented · Jul 01 at 06:05 PM

I have replaced the cable to no avail however I am thinking that it is entirely possible that there is a ground Loop between the GX and the Garmin devices. The GX device is fed from a dedicated 24 volt breaker and one of my Garmin units is being fed from a 12 volt source and the rest are being fed from a 24 volt source. All the equipment is bonded together however I suspect now there may be ground looping. I will rewire the Garmin display from the 12 volt source and get it on the same bus as the rest of the Garmin equipment. I will also rewire the GX to come from the same bus. I will report back ASAP I will update soon with a sketch of the network. Thank you

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screwdriversteve screwdriversteve commented · Jul 06 at 08:07 PM

Okay so I've had some time to get down to the boat and I made a new network cable omitting pins 4,5,7 and 8 and the network has stabilized and it seems to be functioning fine. All of the information that I was able to find on the internet regarding connecting the GX device to a Garmin chartplotter did not use the poe isolator. I have since ordered one and will replace the cable with a standard cable as to not create any future difficulties. I think this is case closed thank you very much for your assistance.

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Answer 2 · 2024-07-11T21:40:49Z

jay-1 answered · 4 days ago

No thanks to Garmin tech suppiort, I finally found a solution to the "discovery loader ready" message during boot up of my GPSMAP 1243 and 743 on the garmin marine network with CerboGX connecrted through GMS10 network switch.

The message is indeed caused by Garmin's use of pins 4,5,7 and 8 for device powerup in a way that conflicts with the CerboGX. If I cut the network wires to these pins, no error during bootup. (alternatively Garmin says using their $63 POE blocker adapter would block these pins.)

The second thing I painfully discovered is the cable connecting the CerboGX and the Garmin network needs to a straight patch ethernet cable. All my Garmin cables were "crossover cables" which would not work with the CerboGX. The message said "searching for device". So I just used a regular ethernet cable instead.

Finally everything works.

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