GARMIN GTX 320A and Encoder converter

[JCmmpt]

Hi there: My RV-9A has an EFIS D100 and a EMS D120. Withe them a GARMIN GTX 320A, Betwen then an altitude encoder. The tower control doesn´t receive my altitude info. We checked the wires and ground contact. Nothing looks like wrong. The setup configuration is in FORMAT 4, the same signal for a GARMIN GTX 327. Is it wrong?
Thanks in advance.
JC Aracaju Brasil

 

[dynonsupport]

Yes, it should be format 1. There's more info in the D100 install manual if you need it.

 

[JCmmpt]

The altitude encoder is from Dynon. We tried format 1 and there is no altitude info in control tower. Only mode A info. Is there another point to check?
Thanks in advance.
JC - Aracaju - Brasil

 

[Werner_Schneider]

JC,

you can confirm, that you have the Dynon transponder blind encoder serial to parallel converter between your D100 and your GTX320A via the 25 pin cable? And that you have wired it according Appendix D?

The 320 does not like the 327 accept a serial datastream.

Werner

 

[JCmmpt]

Thanks Werner: Yes I confirm I have a serial to converter from Dynon betwen Garmin GTX-320 and Dynon EFIS D100 and cables are routed like the manual says. We tried all formats 1,2,3 and 4. There is no reply with altitude. Now I´ve installed an American King altitude encoder, but I steel need your help, ´cause the AK enconder isn´t mine. Where could I check?

 

[dynonsupport]

You can verify that the converter is working with an ohmmeter.

First, make sure the converter has power. It needs 12-30 V. Second, the format for the converter is "1". No reason to mess with this.

You can then look at all of the output lines of the converter with an ohmmeter. Make sure you use the black wire of the ohmmeter on ground and the red one on each output line. If the converter is working and getting a good signal, some of these will show conductivity to ground. Some will not. If none show a connection to ground, the serial line to the converter isn't hooked up right or the converter is broken.

If some show connection to ground, then go into the EFIS "altadj" and move this around a couple hundred feet. This will change the output of the converter, so some of the output wires will change state.

If all of that is working, something is up with your transponder.

 

[Canadian_JOY]

Installing the serial-to-gray-code convertor can be a little confusing, so I would suggest the following checks be done.

1) EFIS Pin 13 connects to GREEN wire from convertor
2) EFIS Pin 21 connects to BLACK wire from convertor (note green and black wires are in a single heat shrink covering at the convertor)
3) Convertor RED wire is connected to +12Vdc power (suggest best place to connect is GTX320A Pin 14, Switched Power Out)
4) Convertor BLACK is connected to Ground (suggest best place to connect is GTX320A Pin 13 or 25)

The following connections should be verified as well:
Garmin GTX320A Pin --> Convertor Wire Colour
3--> Yellow
5--> Green
6--> White/Blue
9--> Blue
11--> Orange
12--> White/Red
10--> White/Green
4--> White
7--> White/Black

I've hooked it up in this manner in my airplane and have verified this works. I hope you get yours working soon!