I need some help with grounding of the RS-232 signals in a G3X system. I have mostly Garmin components except for
a VPX, Guardian CO Det and Artex ELT. On the G3X there are various serial ports and each one has a TX and RX.
There are also a bunch of "signal grounds" that are not assigned to specific ports.

I'm a bit confused about what to do when, say, connecting the G3X to the GEA-24. There are no "signal" grounds on
the GEA-24. For an individual serial port do I need to connect to a signal ground on the G3X? What do I do with that
ground on the other end of the wire (GEA-24 in this case)? I am using shielded wire for all my RS-232 cables. Do I need
to do anything with the wire shield?

Not sure it's relevant but I have 2 ground busses. One behind the panel and the other behind the seat. They are connected
together. I don't use the chassis for any grounding. Everything ground to one of these 2 locations.

Victor