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Connecting Garmin 796 to GRT HX EFIS

PittsCondor

Well Known Member
I'm know this is an old topic but I can't seem to get my 796 to communicate with my GRT HX. Looking for any advice that might help.

I have the Orange Serial 2 wire from the 796 wired to Serial 7 in on the HX. I selected the NMEA format and speed normal.

I'm not sure what baud rate the 796 uses. When I hit the ? mark on the 796 it says 4800 baud is used. When I read some online posts looks like 9600 might be the answer. I have tried both with no luck.

Do I need to ground the Serial 2 in on the 796? I don't think this should matter.

I have this setup to be GPS2 in the HX.

Any suggestions on how I might get this to work?

Thanks.
 
The Hx and 796 do share a common ground, right?
Look at the Hx set up menu page and see if the counter is advancing, that will tell you if the communication link is working.
 
Thanks Bob, The counter is not indexing. It only shows a 1. Both units ground to the ground buss bar. Maybe there is a setup on the 796 to tell it I have the bare wire connection and to enable serial output.
 
Here is more info that may help figure out what the problem is. I have the bare wire harness and the GDL39. I have it wired up but even when I try to set Serial Port 1 the Garmin Transfer format is shows the message "GDL39 Not Detected". I can connect to it via blue tooth but not serial port one. I'm guessing serial port 2 isn't sending data to the GRT either. I can't find this error message on line anywhere with what to check. I did verify the wires are correctly connected but don't know how to verify if they are making a good connection.
 
GDL 39? The GDL39 uses a non-public proprietary software format that Garmin does not share with others. GRT equipment cannot read it.
This is something you need to be careful about. Some equipment (like gps navigators, for the most part) use public-use formats that everyone knows, and so can be used by many devices. Other equipment will only work with stuff from the same manufacturer, unless there is a third party agreement, or someone has reverse engineered the code.
 
Bob, Here I am trying to get the Garmin 796 to communicate with Garmin GDL 39 via serial port 1 but getting message "GDL 39 not detected". On serial port 2 I want to send NMEA info to the GRT EFIS.
 
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