D-180 Connections to GTX-327

[rvbldr3170]

Connecting my D-180 to my GTX-327, I am not sure of the connections.
The schematic with the GTX doesn't show a Dynon hookup, but it shows pins 2 & 20 from the GTX connected to the input for a Garmin 400 or 500 Series, but the RS-232 In 1 & RS-232 Out 1 are pins 19 & 20. Pin 2 from the GTX is RS-232 Out 2
Does the wire from pin 13 on the D-180 connect to pin 19 (RS-232 in 1)? on the GTX? and does the wire from pin 21 on the D-180 connect to pin 20 on the GTX (RS-232 out 1)?
Or does the wire from pin 13 on the D-180 connect to pin 2 on the GTX (RS-232 in 2)?

 

[dynonsupport]

Does the wire from pin 13 on the D-180 connect to pin 19 (RS-232 in 1)? on the GTX?

Yes

and does the wire from pin 21 on the D-180 connect to pin 20 on the GTX (RS-232 out 1)?

No. Strictly speaking, it doesn't need to be connected if the 327 and Dynon are grounded to the same ground plane. But, it generically, it goes to ground. So either pin 13 or 25 on the 327 would be suitable for our pin 21 to go to.