Autopilot issues when using TDS GTNXi

[NiklasL]

Hi,

when using the TDS GTNXi, I observe the following problematic behaviour of the autopilot throughout a range of compatible aircraft (Black square King Air, Baron, Bonanza, Flysimware C414, Milviz C310):

- Arming NAV and APPR mode is not possible, even when one is more than two dots away from the radial/localizer. The NAV mode immediately activazes when pressed and this can lead to some strange intercepts. According to the manuals of the respective autopilots, this is not how it is supposed to work. NAV or APPR should arm and should activate only when within 1.5 dots.
- Only observed in the King Air so far: The airplane drifts away from the glideslope in some cases, sometimes by more than one dot, although APR CPLD and GS are illuminated on the annunciator panel. I cannot imagine that this is realistic.
- I find that ALT HOLD can lead to some oscillations around the target altitude but this might be subjective.

Interestingly, I observe the same behaviour when using the stock Asobo KAP140 autopilot. However, it goes away when using the PMS50+WTT mod or the WTT GNS530W as primary GPS: arming modes is suddenly possible and tracking of the G/P is rock-solid. You can best test this when using the Black square aircraft with hot-swappable avionics where you can compare the autopilot basically side-to-side in the same situation. This is, what leads me to believe, that the TDS uses parts of the Asobo autopilot code which carries over some of the bugs. Is there a way to fix that in a future update?

[adminOwner2]

Hello,

Thank you for your message, most of this is feature requests and not actual bugs of the product, we are interested in revisiting this area in the future in order to improve the simulation, as much as it is possible.

[Truespirit]

Basically, what we need are WTT mods for the GTNXi like the PMS50 has. Perhaps you could make the GTNXi compatible with the WTT integration mods already available for numerous planes on the PMS50 site, or at least collaborate with PMS50 to make them universally compatible with either 750 unit.

I can see perhaps with AAU2 or AAU3, WTT autopilot becoming the simulator default maybe entirely replacing the buggy original Asobo autopilot. Hopefully when that happens, there will no longer be a need for any integration modules.

[adminOwner2]

Hello,

We thank you for your input, however, the TDS GTNXi is NOT using the default Asobo autopilot logic. This is a misconception that we want to clear up, we have our own, custom coding based on how the real unit behaves. We will definitely look into proving all logic where there is room for improvement.

[coldnebo]

Hello,

We thank you for your input, however, the TDS GTNXi is NOT using the default Asobo autopilot logic. This is a misconception that we want to clear up, we have our own, custom coding based on how the real unit behaves. We will definitely look into proving all logic where there is room for improvement.

I had a similar problem with the KAP140 autopilot and we traced to the TDS tray app. 

During the investigation I cleared my Community folder and uninstalled many mods from Marketplace. Not even the tds-gtnxi-gauge was installed.  But I forgot that I had added the TDS app to exe.xml startup, so the TDS tray app was running minimized.  When we finally saw that, I tried running without the TDS app and everything worked normally.  I then looked at the TDS Manager and saw that I was behind by a few updates.  I updated the TDS, renabled the mod, ran the tray, and then the Asobo C172 steamgauge KAP140 worked normally.

This issue was first tracked on the JustFlight support forums, then WBSim, then WorkingTitle, and finally the MSFS Forums. It has taken months of investigation and discussion to find this issue.


My guess is that the TDS tray app is using Simconnect events to establish a handshake or at least react to the tds-gtnxi-gauge mod being activated in the sim?  

For some reason the old tray app reacted to re-engaging the AP by (I think) sending a quick series of events that broke the KAP 140 in the Asobo C172 steamgauge aircraft.  I don't know the details of this, but we have a video recording showing how simply starting the TDS app breaks the KAP 140 reengage in a way that could only be cleared by restarting the flight.

But guesses aside, it would be nice to know what's really going on.

[adminOwner2]

Hello,

We thank you for your input, however, the TDS GTNXi is NOT using the default Asobo autopilot logic. This is a misconception that we want to clear up, we have our own, custom coding based on how the real unit behaves. We will definitely look into proving all logic where there is room for improvement.

I had a similar problem with the KAP140 autopilot and we traced to the TDS tray app. 

During the investigation I cleared my Community folder and uninstalled many mods from Marketplace. Not even the tds-gtnxi-gauge was installed.  But I forgot that I had added the TDS app to exe.xml startup, so the TDS tray app was running minimized.  When we finally saw that, I tried running without the TDS app and everything worked normally.  I then looked at the TDS Manager and saw that I was behind by a few updates.  I updated the TDS, renabled the mod, ran the tray, and then the Asobo C172 steamgauge KAP140 worked normally.

This issue was first tracked on the JustFlight support forums, then WBSim, then WorkingTitle, and finally the MSFS Forums. It has taken months of investigation and discussion to find this issue.


My guess is that the TDS tray app is using Simconnect events to establish a handshake or at least react to the tds-gtnxi-gauge mod being activated in the sim?  

For some reason the old tray app reacted to re-engaging the AP by (I think) sending a quick series of events that broke the KAP 140 in the Asobo C172 steamgauge aircraft.  I don't know the details of this, but we have a video recording showing how simply starting the TDS app breaks the KAP 140 reengage in a way that could only be cleared by restarting the flight.

But guesses aside, it would be nice to know what's really going on.

Hello,

The TDS GTNXi has been coded so it would not interfere with the KAP140 when it is not in use.
At any rate, the tds-gtnxi-gauge from the MSFS community folder does not do the autopilot interactions, the autopilot interactions are done only by the executable.

The JaveScrip part of the project is just there for backwards compatibility with add-ons which did not support the TDS GTNXi out of the box. This is not the case anymore and the file is not called by default, so this is nothing to worry about.


Let's look into what is going on with the TDS GTNXi, with hopes that we can fix it, if it is our bug.

As you have had this problem for quite some time, we strongly think that this is an issue with an outdated version which got resolved since then. The first step is to confirm the version number which you have experienced the problems. Lately we have performed many autopilot changes on our end, so we would advise to update to version 1.0.3.5, then let us know if you still experience the bug. This is very important and I think that the discussion must be started after this point.


We are fully committed to helping resolve any issues that are our own, as quickly as possible, so our software will not interfere with other projects and for us to adhere to industry standards in order for you, as a customer, to enjoy the general flight simulator experience.


If you would like to discuss this matter further, we invite you to our Discord (@TDSSim) or via email at: support@tdssim.com

Discord Link:
https://discord.gg/NupgPCUgsH

[coldnebo]

Hello,

We thank you for your input, however, the TDS GTNXi is NOT using the default Asobo autopilot logic. This is a misconception that we want to clear up, we have our own, custom coding based on how the real unit behaves. We will definitely look into proving all logic where there is room for improvement.

I had a similar problem with the KAP140 autopilot and we traced to the TDS tray app. 

During the investigation I cleared my Community folder and uninstalled many mods from Marketplace. Not even the tds-gtnxi-gauge was installed.  But I forgot that I had added the TDS app to exe.xml startup, so the TDS tray app was running minimized.  When we finally saw that, I tried running without the TDS app and everything worked normally.  I then looked at the TDS Manager and saw that I was behind by a few updates.  I updated the TDS, renabled the mod, ran the tray, and then the Asobo C172 steamgauge KAP140 worked normally.

This issue was first tracked on the JustFlight support forums, then WBSim, then WorkingTitle, and finally the MSFS Forums. It has taken months of investigation and discussion to find this issue.


My guess is that the TDS tray app is using Simconnect events to establish a handshake or at least react to the tds-gtnxi-gauge mod being activated in the sim?  

For some reason the old tray app reacted to re-engaging the AP by (I think) sending a quick series of events that broke the KAP 140 in the Asobo C172 steamgauge aircraft.  I don't know the details of this, but we have a video recording showing how simply starting the TDS app breaks the KAP 140 reengage in a way that could only be cleared by restarting the flight.

But guesses aside, it would be nice to know what's really going on.

Hello,

The TDS GTNXi has been coded so it would not interfere with the KAP140 when it is not in use.
At any rate, the tds-gtnxi-gauge from the MSFS community folder does not do the autopilot interactions, the autopilot interactions are done only by the executable.

The JaveScrip part of the project is just there for backwards compatibility with add-ons which did not support the TDS GTNXi out of the box. This is not the case anymore and the file is not called by default, so this is nothing to worry about.


Let's look into what is going on with the TDS GTNXi, with hopes that we can fix it, if it is our bug.

As you have had this problem for quite some time, we strongly think that this is an issue with an outdated version which got resolved since then. The first step is to confirm the version number which you have experienced the problems. Lately we have performed many autopilot changes on our end, so we would advise to update to version 1.0.3.5, then let us know if you still experience the bug. This is very important and I think that the discussion must be started after this point.


We are fully committed to helping resolve any issues that are our own, as quickly as possible, so our software will not interfere with other projects and for us to adhere to industry standards in order for you, as a customer, to enjoy the general flight simulator experience.


If you would like to discuss this matter further, we invite you to our Discord (@TDSSim) or via email at: support@tdssim.com

Discord Link:
https://discord.gg/NupgPCUgsH

yep, the latest update fixed the issue, sorry if that wasn't clear.

right now the workaround is simple, if you run TDS, check that you have the latest update.  I was just more curious about the action of the tray app and whether it sends sim events to "initialize" the AP systems a certain way for the 750 that might have caused issues.  Based on the investigation I would expect the simevents to be in the tray app code, not the js code.

[adminOwner2]

Hello,

Thank you for understanding us and for letting us know that updating solved the issue.

We are glad to hear this and we do hope that you will still enjoy the TDS GTNXi!