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Garmin GTN driving GTX transponder

CharlieWaffles

CharlieWaffles

Well Known Member
I know the Garmin GTN can control the remote transponders (GTX 32/33) but another builder mentioned it could also control the cheaper standard panel units (GTC 327/330). Has anyone else seen or done this? It says a bit of money if I can use a standard transponder so id like to confirm. My local Garmin provider doesn't think this is possible but they are focused on the certified market.
 
CharlieWaffles said:
I know the Garmin GTN can control the remote transponders (GTX 32/33) but another builder mentioned it could also control the cheaper standard panel units (GTC 327/330). Has anyone else seen or done this? It says a bit of money if I can use a standard transponder so id like to confirm. My local Garmin provider doesn't think this is possible but they are focused on the certified market.
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Stein has mentioned to me on several occasions that it can be done. The 650 manual doesn't specifically mention that functionality. I started to wonder how to accomplish the remote control, but then realized in my stack they are mounted together, so remote control doesn't make sense, so I didn't pursue it.

I'm a couple weeks away from powering up the panel. We'll see how good I'm at keeping all the smoke locked up.
 
Should work

I am putting the GTN 750 in my new 7. I already had a 330S. Stein advised me this would work fine for the transponder function on the 750. I'm remote mounting it.
 
Anyone happen to have an install manual for the GTX 32 or 33? I would like to compare the wiring with the GTX 327 install manual I found.
 
In the later firmware for the 327/330, there is a "remote" setting for the serial input and output. The input enables remote control of the xponder from other devices. The output enables the xponder to remote control other devices like an ADS-B UAT.
 
It is probably possibly but not with the current version (2.10) of GTX-327 firmware. I for one hope Garmin implements this on the GTX-327.

The "REMOTE" feature mentioned above is for the GTX-327 controlling another device such as an ADS-B (GDL-90, Navworx, etc) or other box remotely but not for it to be remotely controlled.

Of the two input RS-232 lines on the GTX-327, one understands only altitude data while the other understands only Aviation data. In a possible future version of firmware for the GTX-327, Garmin may include code to understand control commands from a GTN unit. Maybe they have already done it and there is a newer version than 2.10. Stein can chime in on this.
 
CharlieWaffles said:
Happen to know the software/firmware version required to do this? Can older units be upgraded to support this?
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Yes, I had my older unit previously running version 2.03 upgraded to version 2.10 for the REMOTE feature to allow the GTX-327 to control my Navworx ADS-B box. But unless I am missing something, as mentioned above, you will need something newer than 2.10 for a GTN CONTROL feature.
 
Well I happen to have a brand new one in the airplane. Next time I am at the hangar, I will check. The install manual shows "remote" as a valid input and output mode. I had no reason to try it so I can't say for sure if the input can be set to that yet or not....

But I will let you know.
 
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I just checked the install manual (rev N) for the GTX-327 and in Section 5.2.6 it does list a REMOTE IN setting. In the table is the following entry:

"REMOTE - RS-232 serial input remote data. Reserved for future use"

So now the question is, will this version (2.10) understands the REMOTE control signals from the GTN navigator?
 
Brantel said:
Well I happen to have a brand new one in the airplane. Next time I am at the hangar, I will check. The install manual shows "remote" as a valid input and output mode. I had no reason to try it so I can't say for sure if the input can be set to that yet or not....

But I will let you know.
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I know why I was thinking it did not; The rep in the Garmin booth at OSH assured me that only the remote transponders (GTX 23/32/33) were supported with the GTN REMOTE control feature. I guess a lucky GTN owner can confirm this for us with the 2.10 (or higher) firmware.
 
I've done this on a few aircraft at the shop I work for. The GTN 650/750 will drive the gtx series easily. We just hook a serial port out of the gtn to the gtx and when properly configured the transponder accepts data and works flawlessly. I can check which ports we use when I see our drawings tomorrow, but I can assure you the gtn will work with any gtx.
 
I think we were the first to actually test this and trust me it works just fine...been there done that dozens of times now. We usually don't tell people to do things that don't work or we haven't tested first hand.

Cheers,
Stein
 
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thanks stein. So I can mount a gtx 327 in the tail and allow the GTN in the panel to drive it? Assume this means there is no need to have access at all just like the dedicated remote version.
 
I'm assuming you're using a 750 if you're talking about remote mounting a transponder. So why would you not just go with the 32 or 33 and mount them on the rack behind the 750 where it's designed to go, it would be a lot less hassle. Mounting the 327/330 in the tail sounds like a bit of extra work, wiring, mounting the rack... Also don't forget you're limited to approx 9' of coax assuming you're using rg 400 due to the Db loss of rg 400.
 
Very understandable. I'll look at the latest 327 manuals when I get to work tomorrow and let you know if this can be done. But it is something that we have not done to date and we are Garmins biggest dealer in Canada. I'm very interested to see if this is something that can be done.
 
GTX23?

CharlieWaffles said:
Because the 32/33 is almost 800 more than the standard gtx of similar abilities.
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Did you also consider the GTX23?

The GTX23 is closer in cost to the GTX327, provides TIS-A traffic (which the GTX327 does not) and when connected to an IFR navigator like the GTN650/750, provides ADS-B out in compliance with FAR 91.227 to meet the 2020 mandate (as it is currently defined).

A UAT operating on 978 MHz can also meet the mandate (and provide TIS-B/FIS-B), but the UAT only meets the mandate outside of Class A airspace. If you install a 1090 MHz GTX23 and connect it to the GTN for position data, you are all set for operating in all airspace including that above 18,000'.

Not sure what kind of EFIS you are planning for, but the G3X installation manual shows you all the wiring and configuration required to install a GTX23 in this fashion, remote tune it from the G3X PFD, and receive position data from a GNS4XXW/5XXW or GTN6XX/7XX to be ADS-B Out compliant. The G3X will also remote tune the GTX327 (with/without a GTN) if you choose to go that route.

Steve
 
I am going to use the AFs efis and will be getting traffic via navworx rather than TIS. Im not familiar with the 23 so I'll have to look that up.
 
Designed exclusively for installation with Garmin?s G3X? electronic flight display system in light sport and experimental/kitbuilt aircraft, the GTX 23 is an affordable, full-featured remote digital transponder for Mode S traffic surveillance.
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I see this won't work in my situation.
 
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