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G3X ARINC issues with GNX375 and GNC255

Hello,

I recently did a full panel upgrade to add a dual G3X (460, 470), GNC255, GNX375, GMC307, GEA24, GAD29, and G5.

My system powers up, but after a couple minutes gives me errors:
"Not receiving data on ARINC 429 channel 1" and
"Not receiving data on ARINC 429 channel 2".

The GNX 375 is connected to GAD29 via Channel 1 for GPS.
The GNC 255 NAV is connected to GAD29 via Channel 2 for VOR/ILS.
Pictures and video below...

(All of the equipment was purchased new from Stein with the exception of the GNX375 which was purchased new from SarasotaAvionics.)

Install was done by a local shop wiring has been checked, and checked again.

Software is most recent versions for G3X and LRUs (8.72) and GNX375 (3.10).

I have been in contact with g3xpert since July, and the avionics shop has been talking with them since before that. Still no resolution to date although g3xpert is still trying to help...

- Wiring has been repeatedly checked.
- Most recent software installed.
- Configuration verified on G3X, GNX, and GNC.

Has anyone else experienced anything similar? Resolved the situation?

Video of Issue: https://www.youtube.com/watch?v=B3TTDZudsZg (everything appears to be functioning until the ARINC 1&2 message appears at 2:00 into the video)

Configuration Pictures:
3V61XV1.png
 
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Hello,

Forget the normal mode operation for now. Bring up the PFD in configuration mode, go to the ARINC 429 Configuration page, then power up the GNX 375 and GNC 255.

If you don't get a green check mark next to each of the 2 A429 inputs, the GAD 29 is either not operating or is not properly connected to the GNX/GNC.

Also, view the status of your GAD 29 on the main PFD system information page and verify it is operating and communicating with the system.

I have a G3X Touch system with a GNX 375, and if I just turn off either the GNX 375 or the GAD 29, I receive the same error message about not receiving A429 data from the GNX.

Steve
 
Thanks, Steve.

Talked with Garmin and they wanted me to look at the config page also this time.

I went out to the airport and looked at things in configuration mode. Here is what I saw (video below). Generally:
- GAD 29 appears to be talking on the CAN bus, green check and 0% network errors in config mode device details.
- After a couple minutes, the A429 In Channel 1 and Channel 2 go from NO CHECK to RED X.
- Avionics shop has been over these A429 Channel 1 and Channel 2 connections over and over and has verified them. Unless they are making the same mistake over and over again ... could this be a strange failure mode of the GAD 29?

2020-09-27-N858SB-ARINC Issues (7)
https://www.youtube.com/watch?v=XUt53kTMxgI
a. Starting the system up again from scratch into Config Mode.
b. 00:27 – G5 HSI showing the test signal from the GNX 375 but also has a VFR annunciator.
c. 00:29 – G5 HSI test pattern gone and VFR annunciator is gone. There is a flight plan in the GNX 375 but it does not show up on the G5 HSI.
d. 00:43 – G3X Config Mode Device List A429 shows with green check and detail page shows 0% Network Error Rate
e. 00:46 – G3X Config Mode Device List GPS1 shows green check in device list but A429 on detail page shows no check mark for ARINC 429 in 1.
f. 00:49 – G3X Config Mode Device List VLOC2 shows no check mark in device list and in detail page shows no check mark for the ARINC 429 in 2.
g. 01:16 – GNX 375 has a flight plan loaded, but it is not showing on the G5 HSI display.
h. 01:32 – GNX375 gets a “3D Fix” as shown on the G3X Device List detail page and the G5 HSI simultaneously displays the flight plan but has a VFR annunciator.
i. 01:55 – G3X Configuration Mode ARINC 429 Configuration page has no check marks at all next to either input.
j. 02:08 – Back to system information and A429 still shows green check with 0% network error rate.
k. 02:13 – GPS1 GNX375 still shows green check on device list but no checkmark at all next to ARINC 429 in 1
l. 02:18 – VLOC2 GNC255 still shows no checkmark in the device list and no check mark next to ARINC 429 in 2 in the details tab.
m. 02:20 – VLOC2 and GPS1 simultaneously show a red X in the device list. The details page for VLOC2 shows a red X on the ARINC 429 input 2 and added a blank active frequency line.
n. 02:26 – GPS1 now shows as a red X on the device list. On the details page the ARINC 429 input 1 is also showing a red X.
o. 02:32 – Back on ARINC 429 Configuration page. Red Xs show for the 429 Input 1 and 429 Input 2 lines.
p. 02:47 – A429 still shows as a green checkmark in the device list and has a 0% network error rate.
q. 02:50 – I scroll through each device and each device detail page in the G3X config mode system information section. All devices appear to be good on the CAN BUS with a 0% network error rate.
r. 03:27 – GPS1 red X with detail page showing red X on ARINC 429 in 1
s. 03:30 – VLOC2 red X with detail page showing red X on ARINC 429 in 2
 
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A429 Loopback Testing

Hello James,

Thanks for taking the new video in configuration mode. This confirms that the GAD 29 is alive and communicating just fine on the CAN bus and has the correct software.

Are you sure the 25 pin connector is plugged into the GAD 29? It looks like that none of the A429 inputs/outputs are working, and having the J292 connector removed from the GAD 29 would cause what you are seeing.

It is quite likely a wiring issue and not a GAD 29 issue, but it is easy to test the GAD 29 using a simple loopback connector. Just get a spare 25 pin connector, and install 2 wires between pins 11,12 and 23,24.

This will loop the EFIS/Airdata transmissions coming out of the GAD 29 back into the #1 A429 receive port and put a green check mark on that receiver on the A429 configuration page. This will verify that both the #1 transmitter and receiver are operating correctly. You could add 2 more wires to test the #2 transmitter/receiver if you wished, but that is probably not necessary.

A429_Loopback_Wiring.png

A429_Loopback.png

One additional thing to check. Verify that the pin numbers on your 25 pin connector match the numbers on my connector shown above. I believe that one connector vendor made a batch of bad connectors with the numbers reversed, so someone using one of those connectors would put the wires/pins in the wrong holes and nothing would work.

Steve
 
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Ryan,

Let's make a pact that we will post the solution to our problem once we have them sorted - ok?

I'm hitting this now too :(
 
similar issue on a 430 was upgrade

Ryan, try changing the Arinc 2 in on the Navcom from low to high and see if that doesn't fix the arinc 2 issue. On Arinc 429 1in select mapmx on the configuration page of the G3X and select the same on the navcom.
This was what Garmin had me change on my 430 waas. Not saying it's your problem but worth a try. be sure to take pictures of your original configurations before making any changes if you haven't already. Good luck!
 
This may or may not help others, but tonight I upgraded the firmware on my GTN650 and after rebooting that, my problem disappeared.
 
To throw my $0.02 in - I jumped to conclusions too quickly since I have the same set up and I was receiving ARINC errors on my G3X.

I suppose this is the KISS principle in full effect:

The ARINC error I was receiving was because I was in my hangar and did not have a GPS signal. :eek:

I assumed the GNC was part of the problem because I was getting an RS232 error as well on my G5. I assumed this was an issue of receiving nav data to the G5, but then I realized it was receiving data via CAN. I disabled the RS232 on the G5 and all is well now. :rolleyes:
 
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