ADS-B In offline alert (brief)

[swatson999]

Flying a short hop today, I got a very brief "Caution" notice that said "ADS-B In Offline"...it went away within a few seconds, and I checked and the ADS-B text area on the map said "Full" (before going to "Coast" when I left the coverage area for a while).

Is this something to check into, or just a momentary "glitch" of some kind? I only got the alert once...

 

[swatson999]

I've seen this once more, briefly. The manual says that

"The connected ADS-B traffic/weather receiver has not replied to a status query in the last 30 seconds."

What exactly does that mean? That it got a query but failed to reply? That it didn't get a query and so couldn't reply?

Is this a fault, or a normal condition which is expected occasionally?

 

[Dynon]

Fundamentally, that means that the ADS-B box has gone away for at least 30 seconds. I'd start by looking for an intermittent power or data wire. When you're looking at the serial port configuration page for the ADS-B module, the RX and good sentences activity will tell you when we're seeing data (rx) and whether it's intelligible (good sentences). Having that page up while you jostle the wiring is probably the least invasive way to start troubleshooting.

 

[swatson999]

OK, thanks...if I see it again, I'll start troubleshooting the wiring (it's so rapid that I doubt I'll be able to get to the correct page in flight before it goes away). It's happened twice in smooth conditions, and all crimps were made with a Daniels AFM-8 and pull-tested, so I'd be surprised at a loose connection, but you never know!

Will keep you advised of what I see/find...thanks for the help!

Steve

 

[swatson999]

Nearly 40 flight hours later, this occurred one more time, during a smooth portion of the trip from the west coast to OSH. One alert, then gone, never to return since (over 20-some hours now), despite getting knocked around in turbulence quite a bit at times.

I suspect this is not a wiring problem, but some process has hung and the WDT for it restarts it?

Sorry, but didn't remember the screen to go look at it as it had been so long since it occurred previously.

Not a major issue, certainly...it's only alerting for a few seconds then it comes right back, and apparently VERY intermittently, but something you may wish to look at.

My configuration is
SV1000
Both A/P servos
ADS-B
ARINC 429->430W
EMS 220
single ADAHRS
XPDR 261
Backup battery

Other than that one brief glitch, the system performed absolutely flawlessly and beautifully through 23 hours of flight to and from OSH...ADS-B weather and traffic were excellent tools! Thanks for a great product!

Steve

 

[Dynon]

It might be useful to get a diagnostics data log file within an hour of the event (it takes a bunch of minutes to dump to a usb stick via the load files menu, so you probably want to do that once back on the ground), but I'll check with our engineers whether it would be useful or not.

 

[swatson999]

Sure...just let me know and I can get that for you if you think it would help.

 

[Dynon]

Might help. PM'd instructions.

 

[Dynon]

So we think we understand what's going on here, and our 7.0 update - which comes out this month - should have a fix in for this behavior. Thanks for helping by sending your logs!