CDI Source Port
0-5. GPSX, NAVX, or LOCX (as in, which source have you selected to drive your HSI, on the screen?)
0-7. 0=Off, 1= roll only, 2=pitch only, 3= roll+pitch, 4=yaw, 5=roll+yaw, 6=pitch+yaw, 7=pitch+roll+yaw (yaw doesn’t currently exist, but format supports it). Will read 0 all the time if no AP is installed.
AP Roll Mode
0-4. 0=Heading, 1=Track, 2=NAV, 3=GPS Steering. Always reads zero when AP roll not engaged.
0-3. 0=SBY, 1= GND, 2=ON, 3=ALT
Installation Manual, Appendix E.