SL30 & X96 GPS Connection to Dynon HS34

[flickroll]

For those who have been there done that.....

I am connecting a Garmin SL30 and a Garmin 696 to a Dynon HS34. The Garmin manual calls for a 3 wire shielded serial connection: Tx, Rx, Serial Ground, plus shield connections to ground at both devices (at the SL30 and the other device, in this case the HS34). The HS34 has no serial ground connection. So do I ignore this wire on the SL30, or do I connect the serial ground to ground at the SL30 only? How about the shields? Connect at both ends as the Garmin manual says, or just at the SL30? Or no shields at all as the Dynon manual says?

For the 696 connection, the Dynon manual shows no shields, so I assume this is ok. Correct?

Thanks and Happy New Year!

Jim Shannon
RV-8 N52VV
Charlottesville, VA

[L.Adamson]

I'm interested too, as my Garmin SL40 shows grounding the shields at both ends, and my PS Engineering 8000B audio panel shows just the one end; and specifically states it in the manual.

I opted for just the one end.

L.Adamson

[Brantel]

If the GPS and Radio share a common ground with the HS34 you will not need the serial ground wire at all.

The shield is best only grounded on one end, if it happens to get grounded at both ends and works, then no problem but only grounding on one end helps to prevent ground loops and the issues associated with them.

You could connect the serial ground from the SL30 and the GPS to the pin 17 of the HS34 but it is not required as long as the SL30, GPS and the HS34 all are using the same common ground.