Testing altitude encoded output

[Leonard(Guest)]

Support,

I've got the D10A connected to a Garmin GTX 327. Last night I performed some basic testing as follows:

1. Set D10A serial output to mode 4
2. Set Garmin input to ICARUS

...and nothing or so I thought. I played around with the barometric pressure to see whether the transponder pressure altitude would change. It didn't.

Today I found the following from a previous poster

The output will not change when you change the barometer. The EFIS output is a blind encoder, so it always outputs altituide at standard pressure (29.92). This is what transponders expect to see. The altitude is corrected back at the radar facility so that you don't cause a problem if you forget or mis-set your altimiter.

This would explain why my attempt were fruitless. Is so, then the question becomes: How do I test the communication between the D10A and the transponder on the ground?

Any help appreciated.

Leonard

 

[dynonsupport]

Leonard,
First, the GTX327 won't show an altitude on the display unless it is getting a valid altitude. If the display on the 327 shows a pressure altitude that is the same as the EFIS when it is set to 29.92, then the communication link is working. You can prove this to yourself by leaving the 327 on and turning off the EFIS. After a few seconds the 327's pressure display will indicate an error.

If you really want to see it change on the ground, you can go into the EFIS's ALTADJ menu and change the altitude trim on the EFIS. The ALTADJ adjusts the displayed and outputted altitude, so you can tweak this number up/down by a couple hundred feet and see the change on the 327.

 

[Frankh]

Morning,

So the only manual i got with my 327 was the pilots guide...It gets me to the setup screens and the tells me to scroll thru the menu and good luck!

I saw a label that I think said "serial OUTPUT Icarus".....Well of course it should be "serial INPUT" but I couldn't find the thing I need to change. I set the output on the D100 to "4".

Can anyone help me out?

Thanks

Frank

 

[Frankh]

Oh yes and the 327 is showing "FL ___"........ "FL dash, dash, dash"

Thanks

Frank

 

[lgingell]

Maybe this will help you ;-)

http://www.garmin.com/manuals/GTX327Transponder_InstallationManual.pdf

 

[Frankh]

Cool!

I never got one of those with my tranny!

Thanks

Frank