Trig TN22 compatibility

Would the G3X or Skyview be able to control the remote TT22 transponder? Obviously both companies want you to buy their product but the TT22 is the best deal and functionally, they're all the same thing. They all talk over RS232 so I can't see why one would work and another wouldn't.

Furthermore, would either EFIS pass on GPS data back to the TT22 given they're connected to a WAAS GPS source into the ARINC module?

First, did you mean a Trig TT22 transponder, or a Trig TN72 gps? I’ll assume you meant the TT22 transponder.
The TT22 is interfaced via RS432, not RS232, so it’s a bit unusual. It will read Garmin’s ‘ADSB+’ adsb format, so if you have a 430W, 650, etc., with newer software, you can use the TT22 in stand-alone fashion for adsb-out. Or buy the TN72 or other adsb approved gps. EDIT. Note not all waas gps boxes are approved for adsb use. Many used in efis’s are not.
Garmin and Dynon want you to buy their transponders, so I do not know if the G3X or Skyview can control the TT22. OTOH, GRT efis units will interface with it. The mini boxes have a direct rs432 output; the HX and HXr efis units can control it thru a 232 to 432 adaptor. GRT will sell you a TT22 without the control head, but with the adaptor, for using it with an HX or HXr. I doubt, but do not know, that this is compatible with a Skyview or G3X.
For the record, I use a GRT HX/232 to 432 adaptor/remote mounted TT22. The HX passes thru ground-airborn switching commands. Passed the adsb flight test and got my $500 reward.

Gotcha. It seems like its clearly made for the GRT. I just wonder how the Dynon and Garmin transponders would be any different on the inside.

My own typo: Trig uses RS485 protocol.
What I have heard is that the Dynon hardware is the same, but different software, from standard Trig.
Edit. BTW, I’m not sure any adsb boxes can be fed gps data that has passed thru an efis. The internal delays need to be very small, to keep the position accuracy within spec.
Edit #2. Biggest problem I had was getting into the connector pins on the back of my 420W. Sure wish I had thought ahead, and asked Stein to run an unconnected wire from an unused RS232 port when the harness was first built.

Welcome to VAF

Scott, welcome aboard the good ship VAF

Saguaro said:

Gotcha. It seems like its clearly made for the GRT.

Click to expand...

I doubt it was made for GRT-----but suspect that GRT is the only one of the ones mentioned willing to work with folks to share software protocols.

Dynon and Garmin seem to keep their codes secret, making it so you must buy their products.

Only one of the reasons I prefer GRT.

http://grtavionics.com/home/compatible-equipment/

A slightly different twist...
I installed a TT22 with its dedicated TC20 control head. The TC20 is not only the control head but also the altitude encoder so it has a static air pressure connection.

This pairing has worked flawlessly.

While I have GRT equipment I thought I wanted a fully stand-alone transponder system. I still think that's my preference.

BUT I find the off-axis viewing angle of the TC20 control head is relatively poor. I love the fact that it has a "VFR" button and integral IDENT button, and that I can see the pressure altitude and aircraft ID I'm sending over the 1090ES signal.

Still, I find myself wondering if I wouldn't rather control the transponder from my GRT Mini-X just to get the fantastic readability of the GRT glass rather than the so-so readability of the TC20's screen. Before I go this route I'm going to give consideration to relocating the TC20 to where it will be more directly visible.

As a follow-up and to reply more directly to the OP's question...
Ain't no way Garmin will allow their G3X to work with any other manufacturer's transponder in a seamless fashion. They want you to buy Garmin so they ensure they engineer their equipment to only work with Garmin equipment to the greatest extent possible. I know that sounds like sour grapes however it is an accurate reflection of the Garmin business model.

Both Dynon and Avidyne use their own branded versions of the TT22 transponder. Nobody will say just how different those units are from the Trig-branded product, so we don't have any way of knowing whether the Trig-branded unit will work with either Dynon or Avidyne controllers.

Mark, like you, I wasn?t sure I liked losing transponder control should I lose the #1 EFIS - so I used that as an excuse to upgrade my #2 HS to an HX (along with a dual efis-232 to 485 adaptor). A recent software upgrade now allows me to bring up the transponder menu (with VFR and IDENT buttons) with a single push and hold button push. (HXr already displays this all the time). I also brought the IDENT line out to a button on my stick, which I find handy.

Trig makes two versions of their split body transponders.
They are effectively identical hardware. One is controlled via RS232, the other, as mentioned RS485.

MGL makes a small active interface that fits into the DB25 backshell and this then connects to the MGL EFIS systems as well as an optional approved GPS. MGL works with the standard Trig transponder (the RS485 version). MGL uses the CAN bus, similar to Garmin.

GRT does something similar - they call it a serial adapter and it connects RS232 to their EFIS systems.

Don't think Garmin would see much point in interfacing to the Trig transponder directly - but if you prefer these you can always use them stand-alone. Not a biggie.