Connection Stratux to 4500s

[jwyatt]

Any receiver with the GDL-90 protocol can be used with the AF-4500 using Serial #1 or 3, and 115.2k baud.

I'm trying to feed ADS-B data to my 4500s as described on port 3, 115.2k. The source is a Stratux receiver, whose output format is supposed to be GDL-90 compliant. I get the green ADS-B tower count annunciator on the map screen, and see the traffic and ownship messages counters incrementing in the Maint->About screen, but I don't see the traffic targets displayed on the map. Is there a setting I'm missing somewhere to enable display, or is there a sample known-working traffic message somewhere, that I can compare with what is being sent to the EFIS?

[jwyatt]

The source is a Stratux receiver, whose output format is supposed to be GDL-90 compliant.

If it helps, the attached is a log of serial data sent from the RS232 port of the Stratux. Serial comms aren't my area, but it appears to be formatted according to the GDL-90 spec when viewed with a hex editor.

Hex snippet (ownship + 6 traffic)

FS MI st aa aa aa ll ll ll nn nn nn dd dm ia hh hv vv tt ee cc cc cc cc cc cc cc cc px CR CR FE

7E 0A 01 A8 30 9E 1F 92 39 BE 09 1E 05 59 8A 00 08 00 93 01 53 74 72 61 74 75 78 00 00 30 5A 7E
7E 14 16 FF 00 01 1F B0 9B BD E3 81 11 A9 88 1A 40 00 22 01 44 45 4D 4F 31 00 00 00 00 39 39 7E 
7E 14 12 FF 00 0A 1F 91 94 BD D5 5C 53 79 88 17 F0 00 FF 01 44 45 4D 4F 31 30 00 00 00 69 16 7E 
7E 14 16 FF 00 05 1F 87 EC BD CD 0E 2E E9 88 1C 90 00 F6 01 44 45 4D 4F 35 00 00 00 00 18 6F 7E 
7E 14 16 FF 00 15 1F 9E 11 BE 0B 99 26 E9 88 07 C0 00 45 01 44 45 4D 4F 32 31 00 00 00 BF 57 7E 
7E 14 10 FF 00 1C 1F AF 9D BE 01 DE 5A 19 88 13 50 00 38 01 44 45 4D 4F 32 38 00 00 00 6A A2 7E 
7E 14 12 FF 00 06 1F AF 73 BD F2 72 36 39 88 15 A0 00 2B 01 44 45 4D 4F 36 00 00 00 00 62 93 7E

EDIT:
I have now tried both 115.2k and 56.7k port options (and matching baud on the Stratux), giving the same results.
Added another attachment in case it helps, some data captured to the SD card from Serial 3 using the 4500's diagnostic menu serial logger.

[Shawn McGinnis]

That stratux-gdl90.txt data file worked well for me. The traffic is around KSYN.

[Shawn McGinnis]

This is running from SERIAL_3RX.ASR.txt on an AF-4500s S8.8.35-MV16 Serial #1 ADSB 115K centered at DOKTR.

[jwyatt]

Shawn, thanks for testing those files. The traffic is appearing where it should on those screens. I'm also on S8.8.35-MV16, updated last week from the website -- I had been on 8.8.28 prior.

I notice that the ADSB:# counter in the lower left on your screenshots indicates a number which appears to be the target count. This appears on my screen but it always at 0, so I was wrongly assuming it was # of towers. I still see the ownship & traffic counters incrementing in the about page, so it seems like the messages are decoding, but something's inhibiting them being drawn on the map.

Anything I should be checking in config settings or elsewhere? I'll have some more time this evening to play with it.
Should it matter if I have GPS and/or magnetometer connected? (I have the screen on my desk at home trying to test this before rewiring the connectors in the plane).
Does having the ADS-B NEXRAD display on/off affect traffic display? (I believe it's enabled on my screen).

I know it's near impossible to troubleshoot a problem you can't reproduce, so thanks for any pointers. I'll be happy to send along any other info that might be helpful as well.

[Shawn McGinnis]

It could be a distance, where is the GPS location of the aircraft located? I only get 2 of the three targets of the SERIAL_3RX sitting at KRGK.

[jwyatt]

Sitting on my desk it doesn't have a GPS signal connected, so it has the aircraft located at KRGK but annunciates "no gps". I can hook up a gps tonight and see if that allows it to display.

[jwyatt]

Success! I fed the 4500 a generated GPS signal, and once it had a position, it is displaying traffic as expected. Thanks for your help testing the files and getting me going. I generated some additional test traffic from the Stratux to test the various traffic alert states, as well.

What are the thresholds (relative altitude & distance) for normal/proximity/advisory target states in the current software? Testing generated data, I'm not certain they match what is in the v7.4 manual available online.