Dave,
I have both the G-1000DXA and the G-2800DXA rotors. My (older) G-1000 has the CS23 card soldered inside which has a direct
choice in LOGic. When I got the G-2800 (more beams), the GS232 was way too much ($700). I bought an interface from Idiom Press:
http://www.idiompress.com/rotor-enhancements.php
It mounts inside the rotor control box and shows up as an Hygain DCU-1 in LOGic. Cost is now around $150.
Note that the interface does not READ the direction, it only SETS the desired direction. Calibration is pretty straightforward.
73s, Don