AFS A/P and GNS430W

[jrouault]

It is a bit disconcerting to me that after upgrading my II VSGV to an AFS pilot that the GNS430W WILL NO LONGER direct the auto-pilot without the EFIS in the picture. The autopilot only allows one to manually enter a bank angle and climb/descent rate (without gps signal) and manually enter a track (with gps signal). This worked before the upgrade and I would think it would be basic functionality.... if I have an EFIS failure, I would like to be able to drive the autopilot directly from the GNS430W. In my opinion, not having this capability is a software 'bug'. Trutrak, can you please fix this?

Thanks,

Jason

[TrutrakTech]

Hi Jason,

It's not a software bug, but the way the unit was designed. There really isn't a way to add the capability you're talking about without adding more buttons to the unit, which would require a massive hardware redesign. As Rob stated on his forum, you'll still get GPS ground track from the 430 RS232 output. Once in approach mode, you can press the EFIS button and the unit will follow the approach as normal.

The product is designed to be integrated with the AFS EFIS system, not a stand alone unit.

Please let me know if you have any questions. Thanks!

[jrouault]

Lucas

My AFS autopilot does not get ground track fed into it from the GNS430W. This is the functionality I would desire... As Rob stated on the AFS forum, you need to manually look at the ground track on the GNS430W and then enter it manually into the AFS pilot. This is not optimal and really sounds like a software design issue. Lateral navigation is being output by the GNS430 and the autopilot should be able to receive it directly without the EFIS unit having to be in the picture.

Jason

[TrutrakTech]

Lucas

My AFS autopilot does not get ground track fed into it from the GNS430W. This is the functionality I would desire... As Rob stated on the AFS forum, you need to manually look at the ground track on the GNS430W and then enter it manually into the AFS pilot. This is not optimal and really sounds like a software design issue. Lateral navigation is being output by the GNS430 and the autopilot should be able to receive it directly without the EFIS unit having to be in the picture.

Jason

I misunderstood what you meant. Your AP is functioning as designed. When in "AP" mode, you have access to the GPS track, Alt hold, and vertical speed select. There is not a way to add a GPS Nav feature without adding a complex set of button press delays or extra buttons.

If you're getting the bank angle mode with the EFIS shut off, you need to check your RS232 connection. That should still be connected to the AP as that's where it gets ground track. I hope this helps. Thanks!

[jrouault]

It would seem that the A/P should be able to be sourced from either the EFIS or the GNS430W with out additional buttons or button clicks on the A/P. (the software needs to be able to deal with the flagged vs. unflagged signal) I, like many have a source switch on the panel to select EFIS or 430 as the source... this was useful when I had the standard II VSGV autopilot, and I would like it to also work now that I paid for the upgrade to the AFS pilot. Myself, and Rob at AFS both believe this is something that can be solved simply in the software.

[TrutrakTech]

I have already spoken to the engineer about this previously. As I said, without adding complex button layering or button delays that greatly reduce the simplicity of the system, it just can't be done with the current hardware configuration. We already use button press delays for the setup menus. We can't add any more complexity there.

I will be happy to broach the subject again next week when I speak to him. I will post back with any updates/results. Thanks!

[flyvans.com]

totally agree with jason!

unnecessary limitation!
reminds me of shareware with nag-screens and "pro" versions...

i paid for the "pro"-version by getting the IIVSGV but now i should exchange some wanted features for some i wouldn't want to lose and even pay for it? c'mon you can do better.

monitor the incoming serial stream and decide whatever source / format the ap gets fed/wheter the efis is feeding or not. no need for any hardware changes nor buttons!

simple toggle switch in the wiring harness by the builder if he desires.

rgds bernie

p.s. glad i didn't send out the ap already for the upgrade... would hate to require a third roundtrip since purchase mainly for software upgrades & bugfixes. you definitely need a field upgrade capability for the firmware!

[TrutrakTech]

Let me see if I can put out some of these fires.

First, software updates in the field. Yes, we wish we had done this initially. However, the Digiflight II series and Sorcerer series autopilot core hardwares were designed 5-6 years ago. At that time we didn't think it would be necessary or prudent to add that capability. If you're at all familiar with our EFIS, you'll notice we rectified that previous mistake. Future products will be able to have the software updated in the field.
COMPLETELY redesigning the hardware in 90% of our product line is not an option as redesigning the hardware would also require an entire rewrite of the software. The code is developed to work with the hardware currently in the unit.

Second, the AFS Pilot is designed for full integration with the AFS EFIS, NOT a 430W. In the event of an EFIS failure, you still retain the basic AP modes, i.e. track mode, alt hold, and vertical speed select. There are only three buttons on the unit and a lot of features to get done with those buttons. Button layering with varying degrees of time delays is not something we want to include in the unit as it will GREATLY decrease the ease of use. It is still important to add an RS232 connection to the AP. That gives the track mode its info so that the bank angle backup mode will never even be seen.

Third, removal of the magnetometer. Bill is correct. We removed the magnetometer because we found it to be unreliable in too many uncontrollable conditions. The bank angle mode gives VERY reliable performance for a backup mode. It's much more stable at keeping you on course than the magnetic backup mode was. While we aren't retrofitting units that have the magnetometer free of charge anymore, we are no longer using it in DII units.

I will bring this subject up with the engineer when I talk to him next week. I will gladly post up with any info I gather from that conversation.

I hope I've answered at least SOME of the questions here. One thing I must mention is that I've never been dishonest about the features, functions, and capabilities of either unit. I've been up front with everyone who has inquired.

If anyone would like to discuss anything with me one on one, please feel free to PM me. Thanks!

[flyvans.com]

hi lucas,

you do a good job of extinguishing fires ;-)

and thanks for the explanation.

to me this solution is acceptable (solid track, altitude and vs in the backup mode). still if you have more info coming in on the serial stream, why not use it?
i was under the impression, that even the lateral track mode was gone. sorry if i misread.

and regarding the field updates:
i see why you don't want to (and shouldn't) change anything on the hardware.

sorry if i came across too harsh.

rgds, bernie

[jrouault]

Let me see if I can put out some of these fires.


I will bring this subject up with the engineer when I talk to him next week. I will gladly post up with any info I gather from that conversation.



Any thing come of this discussion?

Thanks,

Jason

[TrutrakTech]

Hi Jason,

At this time there are no plans to make any changes. However, we are going to explore options for implementing a change to allow this capability. It will take some time to test different methods with the available buttons. As soon as anything else materializes, I will put it here. Thanks!

[PhantomPholly]

FWIW, on my original TruTrak I had "off" switches for BOTH data streams (ARINC and Serial) so that I could invoke "failure modes" at will intentionally.

By turning off the ARINC, I could cause my handheld to provide course info. By turning off the Serial too, I could force the unit to fly magnetic headings (older version, and I didn't have the mag heading problems some reported). This was convenient when being vectored as they would always assign mag headings, and it also helped me to understand and prepare for failure modes.

My flight instructor was briefed on each of those switches, too...

:D