EDC-D10A intermittent detection by EFIS-D10A

[Varso]

I just bought an airplane and I am trying to fix this annoying issue.  When I start the EFIS-D10A, it detects perfectly the EDC and the OAT for about 10 to 40 seconds then it displays Remote Compass not Detected and OAT not found. I turn the EFIS off and on, the same thing happens again.  If I disconnect and reconnect the EDC's DB9, I get the same result.  Just short connection time. Removing the OAT gave the same result.

This is the setup:
EFIS Firmware to V4.04 (I do not upgrade as I read I should have EDC communication first)
Harness is from Dynon.
All connections looks good and works for few seconds.

Has anyone have any insight? I suspect the EFIS or the EDC is damaged.

Thanks.

 

[Varso]

After some reading, I found out that the following information is relevant.

Once the few seconds when everything works ok is passed, the Efis display alternates from Remote Compass not Detected to a wrong compass reading every second or so. The OAT will always indicate OAT not found.

 

[Dynon]

Haven't seen this in a looong while, but, if the EFIS flashes back and forth between the "Remote Compass not Detected" message and an actual heading, it usually means that the EDC-D10A and EFIS are running different versions of firmware. The fix for this problem is to to update the firmware on the EFIS with the EDC-D10A connected. This should bring them both up to date and in sync. Before you do that, though, confirm that they're on different versions of software by using the "detect firmware version" in the support program.

 

[Varso]

First, sorry for the long delay.  i did not have a chance to go back to the aircraft before today.

Today, I brought in a computer and tried to get the firmware versions of both the EFIS and EDC with the support program.  Unfortunately, the support program found the EFIS but not the EDC.  I tried about 30 times.  If I pressed the go button within 2 seconds from booting the EFIS I got the message could not communicate with chip #4. Past the 2 seconds boot window, I always got the EFIS SN plus the firmware version with a no EDC detected message.

I also borrowed another EDC today and when connected, the EFIS and the support program reported no remote compass detected.  I found this strange as the EFIS detects my EDC for few seconds on start-up although the support program never detected it.  I know for a fact that my EDC version is not in sync with the EFIS.  As for the borrowed EDC, I do not know it's firmware version.

This week-end, I will remove the EFIS and check the cable pin by pin.

I will post my findings by Monday but if anyone has any suggestions, Please reply.

 

[Varso]

Well, I did check the cable pin by pin today and did find that the Data A and the Ground wires were crossed.  I guess that the former owner did cut the main wire in the past and fail to differentiate the W/G and W wires when repairing it.

I am surprised to see that the EFIS was able to partially detect the remote compass with the Data A and Ground wires crossed.

Please consider this topic as resolved.  If the EFIS still do not see the remote compass after the repair, I will reopen a new one.

Many thanks to the Dynon Support staff for their advice,  Great after-sale support does matter to me.

Varso

 

[Dynon]

What version is the EFIS on? You might try (after you've verified the wiring, particularly between the EDC and the EFIS) updating the EFIS firmware anyway. It might drag the EDC along. Or, after it's been updated, it may be able to see the EDC again. But there's a fair chance we may need to see your EFIS and EDC here. There could be something up with one of them.

 

[Varso]

Well I did repair the wire and the EFIS always detects and displays the compass and the OAT. The OAT is working perfectly however, I just noticed that the reading from the compass is not good.

I calibrated the EFIS/Remote compass last week and the EFIS was reporting accurate readings after the calibration (EFIS not turned off after calibration). This week, I noticed that the compass is stuck on a reading and if I rotate the aircraft by 180° or in any other directions, the compass will move by about 20° and slowly return to its original reading. I could turn the aircraft anywhere within a circle and the compass will still show the same reading.

First, now that I have a different problem, should I start another topic?

I know my EFIS is at version 5.5 and the remote compass is unknow but as my EFIS was previously at 4.04 so it could be at 4.04. Once I repaired my connection, I have tried to re-sync the compass/EFIS to 5.5 but my PC was detecting the EFIS but not the remote compass. I have tried to see the remote compass about 50 times and I gave up.

Could this problem be related to a different firmware version in the EFIS and remote compass?

Varso