Version 6 killed the track output to my Tru Trak

[BMW_X6M]

Background: I was using a skyview serial port output to supply basic NMEA data to my Tru Trak digital AP controller. Once on a flight plan, the Tru Trak would track the magenta line on the sky view. I only have a dynon pitch servo. The Tru Trak servos are installed in the wings from years ago. This has worked great, and I like the fact that the Tru Trak is stand alone, and easy to operate for basic heading hold mode. It will also do a standard rate turn on its own.

After the version 6 update, I am no longer able to get the Tru Trak to lock onto the signal as it had before. The Tru Trak is showing it is receiving a GPS signal, but will not track the magenta line! I tried several times. Maybe I need to set up that port again?

Also, I only have the pitch servo buttons, and no way to enable the HSI buttons, due to the lack of the roll servos recognized by sky view. I am stuck in the basic mode also! I would hope I am not the only one with this predicament. I want the ability for two axis control, without being married to dynon servos.

At this point I will be forced to go back to 5.1, to have my autopilot function to follow a flight plan. Is this an oversight? Or an attempt to force us to install only dynon servos?

 

[dynonsupport]

There was no active change to the NMEA output which is what drives the TruTrak. It should work the way it used to. If we broke it, it's a bug. However, I bet the issue is that your serial ports got changed somehow on the update and you just need to set it right again. If not, let us know and we can see if anything happened accidentally.

Advanced AP mode (and thus VNAV) is only available with two servos. There's a huge bunch of reasons that is true, and it's pretty industry standard that an IFR autopilot includes both axes, not just the pitch. It also would have been far from free for us to implement because of UI issues.

 

[BMW_X6M]

I have checked the serial port, and it was set correctly. I experimented with changing it to none, and the data stopped flowing, and the Tru Trak display changed to reflect this.  I enabled the serial port again, the data started flowing, and the Tru Trak display again changed to reflect this. I tried both 4800 and 9600 baud on the Tru Trak with no change.  It appears that the data stream has lost the navigation information?

Nothing will make it work as it had before, and I am unable to downgrade to 5.1 because the software comes up with a message saying the 5.1 I am trying to reload, is older than what is currently installed, and stops at that point.

I have decided I will probably be forced to change to the Dynon Roll Servo now, and remove the Tru Trak.  I will probably wait until the condition inspection to tackle that job. In the mean time I will connect my GTN-650 directly to the Tru Trak and see if I can make things work that way for now.

 

[Dynon]

We don't believe it to have changed, but we'll look into it.

 

[BMW_X6M]

Update: I connected a serial output from my GTN-650 through a switch to the TruTrak. With this connection, I was able to track a flight plan from the Garmin. Switching back to the SkyView serial output is the same, no flight plan tracking.

This seems to confirm that what was working before, the NMEA data on the serial output from the SkyView, is no longer functioning. I have dual SkyView's and they are connected in parallel for this serial output.

 

[dynonsupport]

Thanks for the report. We're looking into it.

As an FYI, the GTN-650 out is Aviation format, not NMEA, so it tests that your TruTrak input still works, but it's not a perfect test since it's a totally different communication protocol.

 

[dynonsupport]

So we did look into it, and between a 5.1 and a 6.0 system, we can't find any difference in the NMEA out string. In the same setup, the data output is identical.

I think something in your system changed with the update. The most obvious is that the 6.0 update makes all your serial ports be configured the same between multiple screens. If you had NMEA out on serial port 2 on one screen and port 3 on the other, this will no longer work.

One thing to test is if the TruTrak works when only one SkyView is on, and try both SkyViews.

You mention the TruTrak says it's getting "GPS data". Does this go away when you power off the SkyView screen(s)? If not, that data is not quite telling us what we expect.

 

[BMW_X6M]

I have both screens connected in parallel using serial port one. This has not changed AND It worked before the software update to 6.0. I will double check the wire colors, and attempt to fly with one screen off to test again. I had a working situation until after the update.  The Tru Trak is receiving rs-232 data, and indicates "OFF" as it should. When using a flight plan, the OFF should briefly change to a "F", indicating the data received has the flight plan information. This does not happen any more. Once it indicates the "F" you enable the autopilot, and it will then follow the magenta line, and indicate a "0" to show it is on the line, or zero error. This works using the Garmin. It worked before using the SkyView serial output set to NMEA basic. Is there a way to reload 5.1? I could try that also to aid in solving this apparent bug.

 

[Dynon]

Our systems do not have a "downgrading" mechanism to get back to older versions of software, unfortunately.

To deal with the other obvious things - on the mapping side, you definitely have a flightplan or direct-to active, correct? The NMEA output only ever outputs SkyView's navigation, but, you might try cycling through the HSI SRC to make sure that's not affecting things. It shouldn't.

 

[dynonsupport]

Is there a reason that you are using BASIC instead of FULL? I would have thought the TruTrak needed FULL. In any case, it's worth trying FULL.

 

[Dynon]

If that doesn't work, shoot us a PM with your email and phone number. We have some other things for you to try but we'll want to work with you offline.

 

[BMW_X6M]

I sent the PM, and got no response. I still have this problem.
I have been flying using the GTN-650 serial output data to the Tru Trak, and this works just as well as the Dynon USED TO. :'(

 

[Dynon]

Sorry about that. We missed your PM accidentally. I've forwarded your more detailed data to our engineering team. I'm surprised that FULL has never worked, but BASIC did. Anyway, more to come...

 

[BMW_X6M]

Version 6.2 did nothing to fix my problem of no navigation data on the RS-232 signal feeding my Tru Trak roll servo controller. THIS WORKED BEFORE the 6.0 series of updates.
I am left with using my Garmin GTN-650 to drive the roll servo controller for now. I eventually will need to replace the Tru Trak with a Dynon servo, but in the meantime, I wish this nagging problem would get fixed.

 

[dynonsupport]

We have looked at this issue multiple times and spent a few hours on it but cannot find any changes in the output between 5.0, 6.0, or 6.2. Since we can't re-create the issue and we didn't make any known changes to the output, we can't really do anything to fix it.

We're happy to keep working with you on this. Shoot us an email at support at dynonavionics.com with a reference to this thread and we can work through some things.

 

[BMW_X6M]

My theory is this. Because I do not have the Dynon roll servo, I also do not have the roll autopilot buttons. (TRK+ALT or HSI+ALT) As far as the software knows, I only have the pitch servo, so it never goes into the roll tracking mode. This was changed with the 6.0 software revision. Prior to that these button/mode features did not exist. It seems that prior to 6.0, as long as you had a flight plan described with the magenta line, it was in the tracking mode. Now, it seems, it does not go into that mode, unless you push (TRK+ALT or HSI+ALT) which I cannot do.

My thought is that the software could be modified to allow dual axis operation, with this combination of servos.

In my case, I could actually have two roll servos because the Tru Track is located in the left wing, and the Dynon would install in the right wing. It might be time to bite the bullet and upgrade to the Dynon roll servo. I was hoping there may be others in my situation that would benefit from more flexibility in the software to talk to third party devices.

 

[Dynon]

The NMEA serial output actually doesn't change with different autopilot mode engagements, or whether you have any autopilot servo - Dynon or otherwise - installed at all. It's always outputting position, speed, where you're going (according to SV's map), waypoint (according to SV's map), and other information that's useful for navigation in general.

The fact that we changed our Autopilot modes has no bearing on the information that's coming out of the serial port that's available for other devices.

 

[Dynon]

By the way, did you ever try using the NMEA FULL setting? That's the one that we'd expect would work with third party products (it's designed to be identical to the output from most portable GPS units)

 

[BMW_X6M]

I had tried that setting way back with version 4 I believe when I initially connected the Skyview to the Tru Trak.  It did not work then. I can try it again, but the Basic setting had been working before, and now will not. I now use the Skyview just to follow along, while using the GTN-650 for the actual data signal feeding the Tru Trak for roll. I use the Skyview for the altitude hold,climb,descend functions. I just flew two 210 nautical mile legs over the weekend this way. I was on autopilot for several hours.  I will be upgrading to the Skyview servo in the right wing, sometime soon. I will probably keep the Tru Trak in the left wing, unless weight starts to become an issue.

 

[BMW_X6M]

Good News! Today I installed version 7, and also changed the serial port setting to NMEA FULL. To my utter surprise, the Tru Trak was now happy with the data stream! I was able to track the magenta line. When I got back I realized I was so excited I only tested using the Skyview GPS source to the HSI. I still need to test using the Garmin GTN-650 as the source to the HSI. I have already purchased the Dynon roll servo, but have not had the time to get it installed yet. My goal is to work on my IFR rating once I have the complete Dynon package installed and working. Thank you Dynon for continuing to upgrade this product line.