THEORY OF OPERATION ...................................................................................... 112
FATAL ERRORS................................................................................................... 114
SOFT EVENTS..................................................................................................... 117
EVENT MESSAGES .............................................................................................. 120
Invalid BBRAM detected on startup....................................................................................................120
Position recovery, solution snapped to GPS........................................................................................ 120
Heading recovery, solution snapped to GPS........................................................................................120
DPP recovery, solution snapped to GPS..............................................................................................121
GPS receiver fixes not reasonable; try to recover................................................................................121
Gyro readings do not stay within specification....................................................................................121
No Tacho data when GPS is detecting movement...............................................................................122
Excessive tacho data is received for a long period of time..................................................................122
Reverse signal opposite to direction determined by GPS.................................................................... 122
Large jump at power-up.......................................................................................................................122
Oscillator values are not within specification......................................................................................123
Antenna open detected.........................................................................................................................123
Antenna short detected.........................................................................................................................124
Failure to connect to GPS DSP............................................................................................................124
RTC disagreed with GPS time.............................................................................................................124
Gyro Failure.........................................................................................................................................124
ADC Failure.........................................................................................................................................125
Gyro Shorted to 3.3 V..........................................................................................................................125
APPENDIX C: SPECIFICATIONS.................................................. 126 DATA I/O............................................................................................................ 128
GPS ANTENNA................................................................................................... 131
REFERENCE BOARD DIAGRAMS............................................................................ 132
MECHANICAL SPECIFICATION ............................................................................... 135