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A little Auto Pilot Help Please

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Dave12

Well Known Member
This pains me to admit, but I can't get the AP74 to take it's orders from the 496. I have spoken with Dynon and the 180 appears to be set properly. I got into the 496 manual and followed the Advanced NMEA output set-up with negative results. The AP74 works fine on heading and works pretty good on altitude, but does hunt more than I would like for altitude. I feel it in my bones that I have missed something stupid. The 496 and the 180 are just not communicating on track or nav modes. I will admit that this programming stuff is not my passion. Thanks in advance for any help you can be.
 
Well Mr. Gores, once again, you nailed it. One butt connector later my HSI is working like a champ. I departed Cecil Co. A/P this morning and it took me direct to Smoketown, Pa. for their annual fly-in. The Dynon did lose the nav source several times, but each time i got the message, I pressed the nav button and got it right back. Again, many thanks. I still want one of your tanks!
 
It still pains me that Van's has not put the suggested note in the plans to ensure the shield and the center conductor of the coaxial cable going to the ELT MUST be separated. I submitted this suggestion long ago. The plans should state that the wire is indeed a coaxial cable and should indicate what the builder is to do with the center conductor and the shield.

Please let me know if I missed this item in one of the plans revisions.

Will send this item again via e-mail to Van's, if the plans has not yet been corrected/revised.
 
Autopilot loses nav source

Dynon did lose the nav source several times, but each time i got the message, I pressed the nav button and got it right back.
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My autopilot does the same thing. Evidently it is a software issue that Dynon has been unable to solve so far.
I still want one of your tanks!
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I do not intend to make or sell the seat-back tank. If enough builders ask Van's Aircraft to make it, they might do it. You can call them or post on this thread: http://www.vansairforce.com/community/showthread.php?t=75042
Joe Gores
 
Autopilot switches from NAV to TRK problem

Dave12 said:
The Dynon did lose the nav source several times, but each time i got the message, I pressed the nav button and got it right back.
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There is an article in the December 2011 Kitplanes Magazine about the RV-12. On page 14, Mark Cook said:
I also tried the Dynon autopilot for a bit. Martin confessed that he did not have the latest software in the system, so the dropped GPS signal didn't surprise me (that was a problem fixed with new firmware for the 496 some time ago).
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I have had this same problem and assumed that it was a Dynon problem and there was nothing that I could do about it, since I had the latest Dynon firmware. After reading what Mark Cook said, I decided to upgrade the Garmin 496 firmware from my 4.20 to version 4.50. I downloaded the update from Garmin's website and ran the program. The first attempt failed. After plugging into another USB port on the computer, the second attempt was a success. It might be some time before I go on another cross country trip to see if the problem is solved.
Joe Gores
 
Joe, recently I spoke with Dynon regarding this issue and was told that the latest programming update addressed the problem. I checked my D180 and it has the latest update. I still lose the nav signal. It will be interesting to see if this Garmin download helps.
 
Having the same issue

I have had the same issue-happens nearly every time I use the autopilot. I was not sure if it was a GPS issue, Dynon issue, connection issue. What I do know is that the GPS is not losing its satellite signal when this occurs. Sounds from the above posts as though this is a Dynon glitch. I have the latest firmware installed on both the Dynon and the 496 so that clearly does not cure the problem.

Are others seeing this as well?

Jeff
 
Nav Source Lost - Me too

I too get the Nav Source Lost alarm occasionally. The AP goes to Track, and simply pressing Nav puts it back to Nav. It doesn't cause me any real trouble, but would be nice to fix.

I spoke with Dynon about this sometime ago. I was told this had to do with the amount of time elapsed since the D180 had received valid data from the Garmin GPS and that Dynon had lengthened the wait time for valid data from the GPS to as long a period as they felt was safe for autopilot operation. They believed the trouble was with the data coming from the Garmin GPS.

I am thinking it may have to do with the data out setting on the GPS that includes the VHF Comm data(For the SL40). Perhaps this extra data inserted in the serial data stream for the VHF Comm is overly extending the amount of time that is expected by the D180. I don't know if there is a data out setting on the Garmin GPS (mine is a 495) that excludes the VHF Comm data to test my theory. I was planning to look in the 495 settings and see what other data out choices I have.
 
I'm running the lastest firmware version on the 180 and the Garmin 296 and the
AP drops out of Nav into TRK frequently.
 
Andy J said:
I am thinking it may have to do with the data out setting on the GPS that includes the VHF Comm data(For the SL40). Perhaps this extra data inserted in the serial data stream for the VHF Comm is overly extending the amount of time that is expected by the D180. I don't know if there is a data out setting on the Garmin GPS (mine is a 495) that excludes the VHF Comm data to test my theory. I was planning to look in the 495 settings and see what other data out choices I have.
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I tried the AP with the D180 and GPS data setting set to NMEA 4800(No VHF Comm) and had the same "Nav Source Lost" alarm. I spoke to Dynon again and they sound like they aren't going to work on the issue anymore, and that the trouble is with the Garmin(Mine is a 495). Van's suggested the latest Garmin firmware may be the fix, but I am at the most current versions already. Sounds like this little glitch is not going away.
 
I don't know who you talked to at Dynon but you have bad information.

Dynon knows about this glitch, it is well known by them, their beta testers and the end users.

To my knowledge Dynon has not given up on fixing this glitch. This glitch exist with many different brands of GPS's when using a NMEA connection not just Garmin so they know it is a problem on their side.

Dynon's priority has been on the Skyview system lately and there has not been any recent work on the legacy series (at least not at the beta level) but it is my understanding that a new cycle is going to start soon and I will bet my pants that this issue will at least be addressed in that cycle.

Live with the bug for now, it is slightly annoying but not a show stopper...
 
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I just installed a replacement D-180 and went through the set-up from the Dynon Manual. Now I can't seem to get the 496 and the Dynon to talk again. Prior to replacement, no problems other than the occasional "lost nav. source". On the HSI screen I have no info coming from the Garmin. I can't seem to find this issue in the manuals. Any Ideas? Thanks in advance.
 
If you have an autopilot with frequent "Nav Source Lost" errors, consider trying firmware beta version 5.5.A0 from Dynon:
http://dynonavionics.com/downloads/Software/Dynon%20Support%205.5.A0.exe
I had to re-calibrate the AOA but the other settings seemed to have been copied automatically to the new version.
I have only used the autopilot for 2 hours since upgrading to version 5.5.A0, but so far so good. According to Dynon at OSH, the new firmware cured the Nav Source Lost problem for some but not for others.
Joe Gores
 
5.5.A0 does not fix this issue. It has been reported many times now by people that tried it.

The problem with intermittent issues that cannot be replicated on demand is that you never truly know if the issue is solved or not.

This particular issue has a history of being dormant for hours at a time and then reappearing without warning both frequently and infrequently.
 
Did you use Vans locked files?

Joe, did you have to use Vans locked settings files when you did the software update?
 
Not saying Trio is any better of an auto pilot, but I have never had a communication problem with my 496 (with 5 of the last updates) or my GNC 250. Have you tried shielding the RS 232 wires (gps to a/p)?
 
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