Why do I see "ADS-B Degraded" in my traffic displa

Two AXP340s. Both are set for UAT=Yes and I have experimented with one set for 1090=Yes and one with 1090=No.  No matter which Txpdr is active, I get "ADS-B Degraded" on my traffic thumbnail and I don't see traffic displayed on my IFD.

I do not see it listed on the Avidyne website either a Service Bulletin or a Service Information Letter.

Where can I get the document?

On the "Main RS232 Config" setup page, Channel 4 Input and Output are both set to "SkyTrax Trfc+Wx".

This is with 10.2.2.0(.A) on the IFD, and whatever the latest MLB software is.

IIRC, older versions of the MLB and/or IFD install manuals specified using ARINC429 data for traffic.  That part of the setup changed somewhere along the line (maybe with 10.2?).

I spoke with tech support and it's not actually as simple as it might seem.  Your MLB100 and IFD are just not configured the same way.  If it was just the IFD, we could walk you through the settings in maintenance mode.  But since it affects the MLB100, you'll need to hook up to a separate configuration tool that your avionics shop should have.  Tell them to follow Service Bulletin 601-00000-004.

FWIW - this is my experience going through this process almost two years ago. BTW - I posted detailed info regarding this to this forum at the time.

Prior to IFD software version 10.2.0.0, the IFD / MLB100 installation required four wires (input / outputs) for proper Skywatch operation; one ARINC 429 high speed input to the IFD for MLB100 Traffic, one RS232 output from the IFD for GPS data to the MLB100 set to Aviation, and two RS232 (one in and one out) for MLB100 Weather.

Starting with IFD software version 10.2.0.0, the above configuration still works for the Skypath traffic display; however, I believe the RS232 weather input and output settings were renamed Skytrax 100 weather.

IFD software version 10.2.0.0 also introduced the ADS-B traffic display with a different three wire configuration to the MLB100. In my case, for proper ADSB traffic display, the ARINC 429 input was turned off and no longer used. The GPS data RS232 out from the IFD now became ADS-B (+G), and the IFD RS232 in and out (now for traffic and weather) was set to Skytrax weather & traffic. There was also a corresponding MLB100 upgrade to version 4.10 as well as configuration change to accept the IFD ADS-B (+G) format output format per Avidyne SB 601-00000-002.

Now for the issues I encountered that may or may not apply to your situation:

Prior to IFD software release 10.2.0.0, the MLB100 had to use the Aviation RS232 GPS format from the IFD. I also have an engine monitor and ELT that used the same Aviation RS232 output from the IFD. This was necessary because the IFD could only output Aviation format on one RS232 channel; so all three devices were tied to the same RS232 output. Simply changing the Aviation format to ADS-B (+G) (along with the corresponding MLB100 configuration changes) would have worked for my IFD and MLB; however, would have caused my engine monitor and ELT to not have the correct GPS inputs.

With the IFD RS232 GPS and MLB100 configuration format set to Aviation, the IFD RS232 to MLB100 in/out set to Skytrax weather & traffic, and the ARINC 429 input from the MLB100 set to OFF, I had a constant ADSB Degraded message in my IFD's traffic thumbnail. Avidyne Tech support explained that the reason for the ADSB Degraded message was because Aviation format did not include a necessary time stamp in its data stream that is included with ADSB (+G) format; hence the ADSB Degraded message. Avidyne Tech support also stated that the display was fully functional under this scenario albeit with an ever present ADSB Degraded message.

The fix to get rid of the ADSB Degraded message in my case involved a trip to my Avionics shop to have my MLB100 GPS data RS232 wire untied from the other two devices and moved its own RS232 out channel in the back of the IFD. Now its data format could be set to ADSB (+G) without affecting any other connected devices and and the MLB100 configuration set to accept ADSB (+G).

Avidyne Tech Support was great help in resolving this issue for me. Unfortunately, it took my avionics shop a little while to figure out that I knew what I was talking about with my wiring change request. Once that was resolved, everything has worked since.

Lastly, after the fix, my ADSB Degraded message was replaced with a Track Degraded message in the traffic thumbnail during ground operations. This message disappears during the takeoff roll and is addressed as normal in the Avidyne IFD PG.

There is a lot of information above and I hope at least some of it is helpful in your situation. I cannot stress enough to keep Avidyne Tech Support involved with your questions.