EFIS to GTX-327 Connections

[sgfreeman]

I have a D-180 and D-100 with the 180 being the master unit and a Garmin GTX-327 Transponder. The GTX-327 is not displaying altitude data from the Dynon. The settings are per the installation manuals and input from the Dynon forum. I am trying to figure out what the problem is.

The shielded Serial 2 pair from the EFIS has Pin 13 connected to Pin 19 on the GTX-327. Where should the lead from Pin 21 (TX GND) be connected? Right now, it is to my common ground block. Could I have a ground loop in the system? Any help is appreciated.

 

[dynonsupport]

You generally don't need to connect ground for serial connections.

Have you set the Dynon to format 4 and the 327 to Icarus in the menus?

 

[PhantomPholly]

Also, there is a setting for 10 foot or 100 foot increments. If set for 10 foot, try 100 foot. You should be able to change this in-flight. I would start with 100 foot, then IF IT WORKS "try" 10 foot and ask ATC if it is still working.

 

[sgfreeman]

I do have the setting to #4 and Icarus. I have also switched back and forth between 10 and 100 resolution with no affect.

I guess the next thing to try is to disconnect the EFIS Tx2 Gnd (Pin 21) from the ground block and see if that changes anything.

Next, is to remove the EFIS connector and the Transponder connector and do continuity checks on everything since the harness was done by Stark and I assume it is correct.

And finally, disconnect the D-180 fromt he transponder and connect the D-100 to see if it receives data from it thus pointing to the D-180 have an internal problem.

If anyone can think of anything else, let me know

 

[sgfreeman]

Poblem Solved!!!

Found error in the wiring at a juction- gnd and TX2 lead switched.

Scott

 

[PhantomPholly]

Yay!

Wish I could say that I've never had a "self-induced" problem...