GTN650 serial bus connection

[rstiles17]

I am installing a GTN650 and have a question about the "RS 232 Ground" pins on the main connector P1001 (pins 44,45,46). Are these required to interface Dynon devices? I am connecting to an ARINC 429 module, EFIS D6, and SV-XPNDR-26X.

Or do you connect these "RS232 ground" pins to aircraft ground?

(Is Pin 20 on the ARINC module aircraft ground?)

 

[dynonsupport]

If everything in the panel is well-grounded, they won't be neccesary, strictly speaking. But bringing them to any ground on the D37 main Skyview connector works though (pins 21-24 have wires on them already)