Analog Digital Digital Altimeter Altimeter 1 Altimeter 2 Analog-Alt-Signal DA1-Alt-Signal DA2-Alt-Signal Below, Above) 50.2500}wr -50.2500} Analog-Alt -Status DA1-Status-S DA2-Status-signa (Invalid, Validy Fail, NCD, Test Fail, NCD, Test, Norm) Altitude switch SUPERVISORY INFERRED SYSTEM STATE MODE Analog-AIt Dig 1-AIt DOJ-Power-On Valid Valid Cockpit Unknown Unknown Device Fault Inhibit (On, Off] CONTROL Interest ndicator MODES Aircraft Altitude Dig2-AIt Below-threshold Valid Reset T, Fy At-or-above-threshold Invalid Unknown Fault Detected Cannot-be-determined Not Inhibited DOl-Status tOn, Oft] Inhibited On Off Unknown Fault-det Watchdog-Strobe(Highy Watchdog TimerWatchdog Timer {Fail,NCD,Test,Norm} DA2-Status-Signal INT DA2-Alt-Signal {-50..2500} {Fail,NCD,Test,Norm} DA1-Status-Signal INT {-50..2500} DA1-Alt-Signal {Invalid,Valid} Analog-Alt-Status {Below,Above} Analog-Alt-Signal Digital Altimeter Altimeter 1 Analog Altitude Switch Cockpit Fault Indicator Lamp On Off INFERRED SYSTEM STATE DOI-Status On Off Unknown Fault-detected Unknown Cannot-be-determined Below-threshold At-or-above-threshold Aircraft Altitude Valid Invalid Unknown Valid Unknown Invalid Analog-Alt Valid Invalid Unknown Altimeter 2 Digital (DOI) Interest of Device {High} DOI-Power-On DOI-status-signal {On, Off} Watchdog-Strobe {High} Inhibit {On,Off} Reset {T,F} Dig1-Alt Dig2-Alt Operational Fault Detected Startup Inhibited Not Inhibited MODES CONTROL Cockpit Controls MODE SUPERVISORY