The Skytrax100B UAT Receiver has LED indicators. There is a specific behavior pattern associated with the ST100B successful power up sequence. The following sequence and descriptions can help undertand failure conditions and proper power on sequence. 

• Startup
  • White, then off
• Application Load
  • Blue indicates Application is starting
  • Red immediately after blue indicates initialization failure
  • Green immediately after blue (even if it later changes to red half a second later) indicates initialization success
• Application Self-Test
  • The application continuously runs a self-test about  will cycle between Green, Red and Orange(Yellow) depending on the Self-test state:
  • Green:
    • All is well
  • Red:
    • GPS Unavailable
    • HW failure
  • Orange( Yellow):
    • Ownship velocity invalid/unavailable
    • Ownship ICAO address not set
    • Pressure Alt unavailable