Thank you for reading the manual, a few don't bother :
Connect the single wire (serial, set up as Format 4)) from the D10A (pin 13) to the Gtx 328 using Port 1 IN (pin 22) set to Icarus Alt. For a basic install all you need is 3 wires, Power, Ground & the Serial IN.
(You only connect Serial OR grey code, not both).
HTH