Looking thru the Garmin install , cannot find the interconnect for the Gsa28 roll and pitch servo . Looks like the pitch gets info from the canbus and roll gets info from canbus and RS232 . Where does the RS232 tie into ? ( if I am on the right track. Basic single screen GDU370 with GSA 28 servos, GEA24 GSU25 (no gmc 305 ?)