ADS-B In Offline (for just a moment)

[krw5927]

Dynon replied to my case (still haven't installed 12.2) and said that I lost GPS lock momentarily. I certainly don't recall ever losing Skyview GPS during the flight, but the diagnostic file apparently said it did. Is it a case of losing lock so briefly that it's not noticeable to the pilot, but the system throws the ADS-B offline caution instantly?

Is the system possibly "wrong" about having lost GPS lock at all, and throws a caution as if that's what happened?

 

[rtairey]

I may have a related issue. I have the SV GPS and xpdr but not the 470 unit. Once every hour or so, my map screen goes blink for less than a Nano second and I get a caution that GPS signal is lost. Comes back up and all is fine for an hour or for ten hours. Again, think the wiring is fine. If I am losing GPS "lock". How can this be fixed?

 

[Dynon]

krw5927 - Different events in the system sometimes have different "time-outs" before alerts are triggered. It's possible that losing GPS momentarily does not immediately warn about itself, but does about the ADS-B that is unavailable because of that event.

rtairey - That's definitely not exactly normal, although if your GPS puck was occluded that might cause it to not get stellar GPS reception. Where is your SV-GPS-250 mounted?

 

[swatson999]

I never saw a loss of GPS on the SV GPS (navigation was from the 430 via the ARINC box...I don't know *which* one this new GPS gating for ADS-B messages is using), but here is the Alert Log around the time of the most recent event:

6/20/2015 15:23 34.45893 -118.58524 8509 118.1 333.1 -12.4 15:23:41 AUDIO PLAY AA_ALT_APCHING
6/20/2015 15:23 34.45893 -118.58524 8509 118.1 333.1 -12.4 15:23:41 AUDIO PLAY AA_ALT_APCHING
6/20/2015 15:30 34.73069 -118.78004 9208 162.2 328.9 -12.5 15:30:58 TEXT SHOW ADS-B IN OFFLINE
6/20/2015 15:30 34.73069 -118.78004 9208 162.2 328.9 -12.5 15:30:58 AUDIO PLAY SYS_CAUTION
6/20/2015 15:30 34.73069 -118.78004 9208 162.2 328.9 -12.5 15:30:58 AUDIO PLAY SYS_CAUTION
6/20/2015 15:30 34.73212 -118.78108 9198 163.1 328.9 -12.5 15:31:00 TEXT ACK ADS-B IN OFFLINE
6/20/2015 15:31 34.73788 -118.78526 9170 165.4 329 -12.5 15:31:09 TEXT HIDE ADS-B IN OFFLINE
6/20/2015 15:31 34.77062 -118.80923 9093 164.7 329 -12.5 15:31:59 TEXT SHOW CHECK BARO SETTING


No GPS messages in there...

 

[rtairey]

rtairey - That's definitely not exactly normal, although if your GPS puck was occluded that might cause it to not get stellar GPS reception. Where is your SV-GPS-250 mounted?


Puck is under the rear stationary canopy of a tip up RV9A, sitting on a brkt attached to the roll bar brace. Full view of the sky. The momentary blackouts occur in straight and level flight. And just started about a year ago. Before I added a GTN650, would only get the quick blackout. Now that I have the GTN hooked up, I get an audible "cautionary" warning.

 

[Dynon]

Hmm - how do you have your Position/gps roles assigned? In each device's setup in SkyView, they can be set to one of

POS 1, GPS 1, GPS 2, GPS 3, GPS 4, POS 2, POS 3, POS 4

In your setup, you want the SV-GPS-250 as POS 1 and the GTN650 as GPS 1. Is that how they're setup?

 

[rtairey]

Yes, that is the setup protocol. Also, the "blips" started well before addition of the GTN.

 

[Dynon]

It may be that your actual receiver is having a hardware issue. Follow up with our tech support team directly at 425-402-0433 or support at dynonavionics dot com for additional one on one help here.

 

[kurtfly]

I flew about 10 hours over the 4th holiday and experienced about 5 or 6 incidents of "Caution" ADS-B offline.  The ADS-B status line shows "Offline" (or wording like that). These all happened in flight with good GPS coverage.  I too am flying with SV touch at 12.2.  My GNS-430 is the primary GPS source.  In all cases the alarm self clears in about 10 seconds.
Is this the known 12.2 issue?

 

[Jonas]

I get the same warning too, once in a while it shows up when pulling over 3 g, sometimes I'll get it right off the bat on start up. Very random that way.

 

[Jonas]

I get the same warning too, once in a while it shows up when pulling over 3 g, sometimes I'll get it right off the bat on start up.  Very random that way.

I should also add that I'm up in Canada, where ADSB doesn't even work, so I'm always not getting any signal from the stations, until I cross the border. (so I don't think it's a signal strength issue)

 

[kurtfly]

I would like Dynon confirm these are nuisance warnings and fix is in work.  This problem just started since upgrading to 12.2.

I would like to add that I do not believe the ADS-B service deserves a "Caution" audio warning either. Maybe a "Message" but I would reserve "Cautions", and "Warnings" to potential safety of flight, actual safety issues. I don't think I would divert or land short of destination due to ADS-B offline.

 

[swatson999]

Happened twice today on a one-hour flight. Same symptoms. Running the latest firmware.

This time, my primary GPS was not the 430W, but the Dynon puck (Garmin box was out of the tray, so there was no data at all from it), unlike previous times where that's the primary source for navigation data.

 

[krw5927]

Interesting timing, Steve.  Happened to me on a 1.0 hr flight the same day (sat the 7th).  Sure hope Dynon can get a handle on this.  I'm a bit tired of hearing the "Caution" annunciation in flight.

 

[swatson999]

Again, last night, for about 10-15 seconds, one time only, in straight and level flight.

I can send the diagnostic file if requested.

 

[krw5927]

Steve, thank you for posting. It's comforting to know I'm not the only one having this problem.

In my emails with Dynon, I sent a diagnostic and they suggested that I had an installation problem or GPS reception issue. I don't believe that to be true, and there doesn't seem to be much traction toward fixing or even further investigating the issue.

 

[swatson999]

I sent a diagnostic a while back, too...I also don't believe this to be an installation or GPS reception issue.

 

[jabarr]

Just as another data point, I've had the ADSB box for quite a while now and have never had the offline occurance that you have experienced.  I have the Dynon gps puck only--no 430 installed.  I have the latest firmware (13.0.3).  All of my flying has been in the southeast US.  My gps puck is located on top of the fuselage behind the canopy. My ADSB box and antenna are in the aft fuselage with the antenna mounted on the belly well away from other antennas. Again this is just another data point.

 

[krw5927]

On a half hour flight this morning my Skyview showed the caution message and ADS-B offline the entire time. Shut down for about an hour, and upon re-start everything was fine for the entire flight home.

I wonder if Dynon is reading this thread any more.

 

[dynonsupport]

Normally, customers that experience a hardware failure such as you're now reporting, and feel a sense of urgency to get the issue corrected, contact Dynon Avionics Technical Support for direct assistance. That number again is 425-402-0433, or email directly to them support AT dynonavionics DOT com. If you do contact TS, please reference this thread.

The discussions here on the forum are more conversational, mostly between customers, with Dynon personnel chiming in from time to time to answer questions and explain issues that are more general interest.

For a specific issue, with a specific aircraft / customer / installation, the most efficient, fastest way to get assistance is to contact Dynon Avionics Technical Support:
phone 425-402-0433
email support AT dynonavionics DOT com

On a half hour flight this morning my Skyview showed the caution message and ADS-B offline the entire time.  Shut down for about an hour, and upon re-start everything was fine for the entire flight home.

I wonder if Dynon is reading this thread any more.