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Wiring Recommends: GTN650+GRT HXr+ARINC+Trig TT-31

walkman

Well Known Member
I need some recommends on wiring and configuration wrt ADSB.

I have GRT HXr, GRT ARINC adapter, GTN 650, and a now a Trig TT-31 (replacing KT-76C), and ACK-350 grey code blind encoder.

When I built the panel 5 years ago I pre-wired a pigtail to the transponder with a serial port from the EFIS and another from the GTN. Now I'm wondering if this is the optimal solution today.

In particular are the TIS-B traffic and GPS ALT adjustment features. Is there value for instance in providing traffic to the 650 instead of, or along with, traffic to the EFIS?

I have a spare "out" port on the ARINC adapter available as well.

Is it still the best option to provide position information from the GTN650 to the XPDR and take traffic information from the XPDR to the EFIS via another serial?

Or are there better options, like providing position from the EFIS via the ARINC port? or Traffic to the 650 via serial or ARINC?

Thanks
 
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Okay, forgive me if I?m wrong, but you sound confused. This equipment can get you ADSB-out, which is all you need to be legal, but it will not get you ADSB-in traffic and weather. I have a GRT HX, G420W, Trig TT-22; not too different.
ADSB-out. Your Trig can send out mode S-ES adsb-out data. You will need to connect the two RS232 pigtails, as you described. You need to use the Garmin format ?ADSB+? to send gps data from the 650 to the Trig. And you need the HXr to send heading, adsb-in capabilities, altitude, etc. to the Trig. I forget the format. Why the external encoder? The encoder built into the grt EIS works fine, and will be sent thru the RS232 connection. If you keep the ACK, it must be configured so the same encoder drives both the transponder and the adsb data. I think this can be done but not sure how. Likewise, the HXr has built-in ARINC. Not sure why you need the external module.
ADSB-in: In the ATL area you may get some TIS-A traffic from your transponder, but it?s only available in a few areas. Not sure if it is outputted via arinc orRS232. But away from ATL you won?t get anything. If you want adsb-in traffic and weather you need an adsb-in receiver, with an output compatible with your HXr. I use a SkyRadar D2, remote mounted, works fine on the HX, fed via usb. There are other options, check the GRT web site. I wouldn?t bother trying to display traffic-weather on the Garmin gps?the HXr display is much larger.
 
Okay, forgive me if I?m wrong, but you sound confused.

Precisely

This equipment can get you ADSB-out, which is all you need to be legal, but it will not get you ADSB-in traffic and weather. I have a GRT HX, G420W, Trig TT-22; not too different.

I have the Skyradar D2 which for years has been giving me Wx and ADSB traffic, but as I understand it there is also TIS-B traffic and some altitude compensation :confused:

ADSB-out. Your Trig can send out mode S-ES adsb-out data. You will need to connect the two RS232 pigtails, as you described. You need to use the Garmin format ?ADSB+? to send gps data from the 650 to the Trig. And you need the HXr to send heading, adsb-in capabilities, altitude, etc. to the Trig. I forget the format.

ok that all makes sense

Why the external encoder? The encoder built into the grt EIS works fine, and will be sent thru the RS232 connection. If you keep the ACK, it must be configured so the same encoder drives both the transponder and the adsb data. I think this can be done but not sure how. Likewise, the HXr has built-in ARINC. Not sure why you need the external module.

I was unaware the HXr had a built-in encoder. Mine is 5 years old, perhaps models changed? Or perhaps I kept the ACK because my KT-76C doesn't take serial data. I'll have to check.

My HXr does not have built-in ARINC, or at least no enough (need to refresh myself) I needed the external ARINC module to take the ARINC data from the GTN for VOR/LOC/ILS as I recall.

ADSB-in: In the ATL area you may get some TIS-A traffic from your transponder, but it?s only available in a few areas. Not sure if it is outputted via arinc orRS232. But away from ATL you won?t get anything. ... I wouldn?t bother trying to display traffic-weather on the Garmin gps?the HXr display is much larger.

If there is limited/no value sending traffic to the GPS (ie its display only) then I won't bother.
 
The 2 in the skyradar D2 stands for two frequencies, 978 and 1099 MHz. The latter is the transponder frequency. All traffic that?s available, it will get it. The TIS traffic from the transponder is very limited to only a few places. I don?t know what you mean by altitude compensation? If you meant filtering traffic by altitude (e.g., display only traffic within 3000 vertical feet, or display all traffic, etc) that is done in the HXr setup.
The remote mounted air data computer has pitot and static inputs, and an altitude encoder. Easy to send the serial data to the TT31 and, as required, send the same-source serial altitude data to the ADSB -out data stream.
All HXr units have two ARINC input pairs, and one ARINC output pair. The output can go to multiple inputs, e.g., the 650 and an autopilot. The two inputs usually are used for the gps and vor-loc outputs from the G650. Not sure why you need additional arinc pairs?
Finally, not only is the HXr screen much larger and easier to use for wx and/or traffic, than the 650 screen, there?s another issue: traffic/wx to the garmin must use a Garmin-proprietary format, which pretty much restricts you to a Garmin device that will not work with the HXr. Since you already have the Skyradar, you?d need to buy a garmin adsb-in box to feed the 650. BTW, your Skyradar will also send via wifi the adsb-in info to an iPad running either WingX, or Skyradar?s map software.
 
...the skyradar D2 ...All traffic that?s available, it will get it. The TIS traffic from the transponder is very limited to only a few places.

right, I'll skip that then
. don?t know what you mean by altitude compensation? If you meant filtering traffic by altitude (e.g., display only traffic within 3000 vertical feet, or display all traffic, etc) that is done in the HXr setup.

no I read somewhere about a mechanism to compensate error in gps altitude with barometric altitude, but clearly its a non-issue, so skip that too

.
The remote mounted air data computer has pitot and static inputs, and an altitude encoder. Easy to send the serial data to the TT31 and, as required, send the same-source serial altitude data to the ADSB -out data stream.

so the HXr doesn't pass altitude data in the serial data to the xpdr? I need a 3rd serial line from the AHRS?

.
All HXr units have two ARINC input pairs, and one ARINC output pair. The output can go to multiple inputs, e.g., the 650 and an autopilot. The two inputs usually are used for the gps and vor-loc outputs from the G650. Not sure why you need additional arinc pairs?

I pretty sure its because I have a Mini AP as well and wanted to be able to take any input from the 650 to the Mini as well as the HXr.
 
The HXr will pass altitude data to the trig, for both transponder and adsb, one wire. But you need to configure it to do so. Sounded like you had it configured to use the ack encoder.
With regard to the arinc out pairs from the 650: each pair can be split, and sent to the arinc-in ports on both the HXr and the mini. Each input can only be fed by a single source, but one output can drive multiple inputs.
 
Hmmm with both an HX and a Mini-AP you might be just as well off installing another switch in the equation to fully preserve the redundancy that you bought with the Mini-AP. This switch would essentially switch the ARINC 429 Ins and Outs going to the HX, splitting them so you can select whether they go to the HX or Mini-AP.

As for encoded altitude, yes, you would install an RS232 OUT wire from the HX to the transponder for this altitude info usign port setting FADC if I recall correctly.

BTW I have a similar configuration, not the same, but close enough. HX, Mini-X, GNS480, TT22. It all plays very nicely together, but of course I don't have the ARINC 429 capability that you have in the Mini-AP. That part's not so hard to sort out. The aforementioned switch would likely be left in the HX position so the HX is getting everything from the GTN.

BTW you didn't mention which AP you're using - assume it's GRT servos, but which device, HX or Mini-AP is currently set to drive the servos?
 
Hmmm with both an HX and a Mini-AP you might be just as well off installing another switch in the equation to fully preserve the redundancy that you bought with the Mini-AP. This switch would essentially switch the ARINC 429 Ins and Outs going to the HX, splitting them so you can select whether they go to the HX or Mini-AP.

As for encoded altitude, yes, you would install an RS232 OUT wire from the HX to the transponder for this altitude info usign port setting FADC if I recall correctly.

BTW I have a similar configuration, not the same, but close enough. HX, Mini-X, GNS480, TT22. It all plays very nicely together, but of course I don't have the ARINC 429 capability that you have in the Mini-AP. That part's not so hard to sort out. The aforementioned switch would likely be left in the HX position so the HX is getting everything from the GTN.

BTW you didn't mention which AP you're using - assume it's GRT servos, but which device, HX or Mini-AP is currently set to drive the servos?

I have a switch to flip between either device. When I designed the panel the intent was to have full IFR capability to complete the flight even if I lost the HXr. A/P is a go/no go thing for IFR flight for me.
 
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