Digital altitude Altimeterstatus altitude Altimeterstatus Analog altitude Altimeterstatus Altitude Device of interest InterfaceA Inhibit Signal Switch Power-on Signal (DOI) Reset Signal DOI Status Signal Strobe Watchdog TimerAltimeter Digital Altimeter Analog Digital Altimeter Pilot Interface Device of Interest Switch (DOI) Altitude Watchdog Timer Power-on Signal Strobe DOI Status Signal altitude status altitude status altitude status Inhibit Signal Reset Signal