uint64 timestamp		# time since system start (microseconds)

uint64 SUBSYSTEM_TYPE_GYRO = 1
uint64 SUBSYSTEM_TYPE_ACC = 2
uint64 SUBSYSTEM_TYPE_MAG = 4
uint64 SUBSYSTEM_TYPE_ABSPRESSURE = 8
uint64 SUBSYSTEM_TYPE_DIFFPRESSURE = 16
uint64 SUBSYSTEM_TYPE_GPS = 32
uint64 SUBSYSTEM_TYPE_OPTICALFLOW = 64
uint64 SUBSYSTEM_TYPE_CVPOSITION = 128
uint64 SUBSYSTEM_TYPE_LASERPOSITION = 256
uint64 SUBSYSTEM_TYPE_EXTERNALGROUNDTRUTH = 512
uint64 SUBSYSTEM_TYPE_ANGULARRATECONTROL = 1024
uint64 SUBSYSTEM_TYPE_ATTITUDESTABILIZATION = 2048
uint64 SUBSYSTEM_TYPE_YAWPOSITION = 4096
uint64 SUBSYSTEM_TYPE_ALTITUDECONTROL = 8192
uint64 SUBSYSTEM_TYPE_POSITIONCONTROL = 16384
uint64 SUBSYSTEM_TYPE_MOTORCONTROL = 32768
uint64 SUBSYSTEM_TYPE_RCRECEIVER = 65536
uint64 SUBSYSTEM_TYPE_GYRO2 = 131072
uint64 SUBSYSTEM_TYPE_ACC2 = 262144
uint64 SUBSYSTEM_TYPE_MAG2 = 524288
uint64 SUBSYSTEM_TYPE_GEOFENCE = 1048576
uint64 SUBSYSTEM_TYPE_AHRS = 2097152
uint64 SUBSYSTEM_TYPE_TERRAIN = 4194304
uint64 SUBSYSTEM_TYPE_REVERSEMOTOR = 8388608
uint64 SUBSYSTEM_TYPE_LOGGING = 16777216
uint64 SUBSYSTEM_TYPE_SENSORBATTERY = 33554432
uint64 SUBSYSTEM_TYPE_SENSORPROXIMITY = 67108864
uint64 SUBSYSTEM_TYPE_SATCOM = 134217728

bool present
bool enabled
bool ok
uint64 subsystem_type

uint8 ORB_QUEUE_LENGTH = 5