Lost CDI after 5.1.1 upgrade

[sposner]

Have D-100 + D-120 pair. After upgrading to 5.1.1 I lost the CDI display (checked setup and it should be displaying as always did). The bos IS still talking to the GPS - getting wind arrow and violet ground track marker etc. All other functions seem to be working.

Support have you seen this before? Any suggestions? Thanks.

 

[Brantel]

You did not mention your GPS type so this is just a guess...

If you are using a Garmin X96, go to the advanced NMEA settings and set the output to NORMAL instead of FAST.

 

[dynonsupport]

What kind of GPS?

When you were checking, did you have a waypoint programmed into your GPS?

 

[sposner]

Garmin 396. Waypoint was programmed in. This was in flight, same as I've done for the past year. Only difference was this was 1st flight after upgrading to 5.1.1.

The EFIS is displaying the violet ground track icon on the compass tape so must be talking successfully to the GPS.

 

[Brantel]

Did you check your advanced NMEA settings? Is yours set for fast or normal? It must be set to normal to work correctly....

 

[sposner]

Brantel - thanks for the suggestion. I've delayed responding because I haven't gotten out to the airport to check yet but I will today and report back. Whether this works or not I still appreciate the helpful input.

 

[sposner]

Brantel - You were right on!!! Thanks. In advanced NMEA switched to NORMAL from FAST and CDI reappeared. What is unusual is I've been operating on fast mode for the past year and previous Dynon software versions were perfectly happy with it. Only 5.1.1 didn't play with it nicely.

All is well now. Thanks.

 

[sposner]

Dynon, we really need you to look at the problem with 5.1.1 not displaying CDI when connected to a Garmin 396 or 496 GPS when set to FAST NMEA output (previous Dynon firmware versions did not have this problem).

Although setting the Garmin to "NORMAL" speed NMEA output seems to cure the lost CDI problem, this causes problems with other avionics that may be interfaced with the Garmin (like Tru-Trak autopilots) which require the "FAST" parameter to dependably communicate with the GPS.

I have had to rollback my Dynon to 5.0.0 in order to keep all my avionics talking to each other.

 

[dynonsupport]

We haven't heard of any issues with any other avionics not working when set to normal. We have lots of installs with TruTraks and our equipment and as far as we know it works fine. The x96 still sends out
all the data it would in FAST mode, it just sends out more data. Have you actually tested your other stuff when set to fast and are sure it stops working?

 

[sposner]

Thanks for your very quick response. The Tru-Trak is the only other box other than the Dynon pair that is interfaced with the GPS. The documentation for the Tru-Trak autopilot specifies the Garmin 396 be set to "FAST." When it's on NORMAL my autopilot occassionally drops the Garmin flight plan (i.e. I lose the "-F-" on the autopilot and it won't track the GPS). When set to FAST this doesn't happen.

In all previous Dynon firmware revisions the Dynon boxes were happy to play with Garmin in FAST mode and all was at peace. But it is clear that Dynon 5.1.1 won't display CDI now with Garmin in FAST mode. Something obviously has changed with the latest upgrade.

 

[dynonsupport]

The issue with fast output is that the GPS basically truncates some information in order to repeat the sentences often enough. In practice, this means that the course on our HSI display will always point to 360 because that info ends up not being broadcasted by the GPS. Unfortunately, due to this limitation, we aren't able to support the fast output because there's information there that the HSI needs.

A few things - make sure that you're choosing one of the NMEA options that has 9600 baud output. Also, you may or may not (haven't tested this) be able to get away with fast if you deselect some of the other sentences. We need the ones mentioned here, so you might try turning off GSA/GSV in the menu to see if that pares down the list so that the course information makes it through.

 

[PhantomPholly]

I don't know which TruTrak product you have, but the install manual for II VSGV says 4800 baud (9600 is "High").  I think it is for the reaon Dynon mentioned, that it truncates "sentances" at high speed.

 

[dynonsupport]

Also, just to be 100% clear, the "normal/fast" data rate option is different and separate from the baud rate 4800/9600 choice. Ideally, 9600 and normal are the two you want paired for best Dynon compatibility.

 

[sposner]

Just upgraded the Garmin 396 software to ver. 4.9 released in September and now the Tru-Trak autopilot locks onto the "normal" NMEA output which Dynon likes. I then re-upgraded the Dynons back to 5.1.1 and all boxes are now happy.

 

[dynonsupport]

Great! Thanks for the follow up and solution. Feedback is always very appreciated.

 

[almarton]

Hi, I think this solution here will solve the problem I am having describe on my post below:

http://dynonavionics.com/cgi-bin/yabb2/YaBB.pl?num=1255954910/3#3

I got GPS on HSI but can't access NAV function on AP74, it does not engage and the button does not come lit when pressed.

I think it has something to do with GPS baud rate as described, but please clarify if I should set as

GARMIN 296 to:

Aviation in / NMEA out
9600 baud rate
normal (on advanced NMEA setting , is that on GPS menu?)

EFIS to:
auto baud rate

Is that it? :-?
Thanks
Alex.

 

[dynonsupport]

Yes, that should do it.

 

[landwerlen]

i know this is an old thred, but im having the same problems with my garmin 296. after ugrading to 5.2 from 4.0 the course indicator is locked on 360 and the cdi is gone.

i have the latest 296 software 5.8, and there is no advanced NMEA setup on the 296.

aviation in/nmea and vhf out is the only option that has a nmea output at 9600.

does 5.3 resolve this? thanks for the help guys!!!!

 

[landwerlen]

Im sorry, there IS an advanced NMEA setup on the 296. its a little tricky to get into. with out the 296 manual i probably would have not stumbled into it. it was on fast. i've changed it to normal, and trust that will get things really back to normal.

 

[dynonsupport]

If it's like the 396/496, you highlight the mnea format then hit menu, then go to the advanced option. Then change output rate to normal.