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What's required for GPSS & GPSV

rracer10

Member
I've been to the TT website to determine what is required to drive the DigiFlight II with GPSS & GPSV and all I can find is "when coupled to certain EFIS systems or a GPS with vertical GPS steering outputs." :confused:

Does the Garmin GPS 696 have what it takes to drive the GPSS & GPSV on the TT? What output is the TT looking for ?
 
You need a source that supports GPSS and or GPSV and in 99% of the cases, that device must support ARINC 429 interfaces for the connection method. Most modern panel mount GPS's will output GPSS. A few early panel mounts had the ability to output GPSS over serial but this was not widely accepted or supported by AP makers.

For GPSV, the GPS most likely will need to be a WAAS enabled panel mount GPS like the 430W or an EFIS that generates GPSV signals.

The 696 cannot output GPSS or GPSV and does not have ARINC 429 interfaces. It can only provide NMEA data for GPS Nav over serial RS232.
 
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ARINC 429

Yeah, I found the ARINC A & B requirement for the GPSS & GPSV. The 696 does have WAAS which is required for the GPSV but it lacks the ARINC output.

Thanks ! :)
 
Big difference in how the 696 uses WAAS vs how a panel mounted IFR GPS does. The 696 has limited ability to provide vertical steering signals....

Yeah, I found the ARINC A & B requirement for the GPSS & GPSV. The 696 does have WAAS which is required for the GPSV but it lacks the ARINC output.

Thanks ! :)
 
EFIS ?

So, certainly as you mentioned the 430W GPS would provide the ARINC stream required, but how about EFIS systems (ex. GRT, Dynon, MGL, AFS, etc.). Could you have the GPS 696 connected to a EFIS then from the EFIS have ARINC output to drive the GPSS & GPSV for the TT.
 
Yes, some EFIS's have the ability to transfigure data sources and create ARINC 429 commands for driving the AP's....GRT, MGL, AFS all do this in some way or the other...Dynon's legacy systems do not. The new Skyview may do it in the future but I don't know for sure and for that you need to talk to Dynon.

So, certainly as you mentioned the 430W GPS would provide the ARINC stream required, but how about EFIS systems (ex. GRT, Dynon, MGL, AFS, etc.). Could you have the GPS 696 connected to a EFIS then from the EFIS have ARINC output to drive the GPSS & GPSV for the TT.
 
If we're talking about TruTrak (or Trio) A/P's with ARINC then the well proven EFISes that provide this functionality (of ARINC output driving the appropriate A/P) are GRT, AFS, Garmin, & Chelton. All of the aformentioned companies have put a ton of R&D support into very tight interfaces with a good A/P. Blue Mountain kinda/sort went their own way, Dynon is going their own way, MGL is going their own way, and OP kinds/sorta has an interface...each with differing levels of success and proven functionality/reliability. AFS has it's own branded A/P that is tightly integrated, the new G3X has a fantastic A/P integration, and so do the GRT horizon's.

Even if you do feed these boxes with a 696, it won't matter much because the 696 isn't feeding GPSV. The EFISes themselves (again to differing levels of functionality) will generate their own signals to drive the A/P's regardless of input. At the moment the only good boxes with solid GPSV to drive said EFISes are the 430/530's, 480's, the Chelton/Freeflight GPS, and a select few other boxes that are not particularly popular amongst GA users. In contrast, if you purchase a Garmin GDU instead of the 696, the GDU has the capability to be expanded into a full blown EFIS with ARINC ports, etc..

My 2 cents as usual.

Cheers,
Stein
 
Yes, some EFIS's have the ability to transfigure data sources and create ARINC 429 commands for driving the AP's....GRT, MGL, AFS all do this in some way or the other...Dynon's legacy systems do not. The new Skyview may do it in the future but I don't know for sure and for that you need to talk to Dynon.

I talked to a Dynon rep at a show this last weekend. He said that ARINC-429 to drive an autopilot was very low on Dynon's list, as in they probably won't do it any time soon or at all. The reason is because they would rather spend time on their own autopilot.

I guess that makes sense, but it does mean that the dynon stuff doesn't really integrate with other vendors, so be sure you like what dynon will give you before you go that route.
 
Will an SL30 and a GX autopilot with a G3X EFIS allow for coupled VOR/LOC/ILS approaches with lateral and vertical guidance?
 
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