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System Status

Solution Status

Solution Alignment

Solution alignment occurs when aiding sensor and state estimation are in agreement and indicates that solution output can be trusted.

Heading Alignment

Heading alignment varies based on available sensors and conditions of motion.

Stationary INS and AHRS (no GPS) use the magnetometer for heading alignment. The INS solution will start and remain in INS_ALIGNING status (1) until the magnetometer calibration is validated. The magnetometer requires +- 45 degrees of rotation to validate calibration and ensure accurate heading.

Moving INS (under accelerated conditions) or Dual GNSS (two GPS antennas using RTK compassing) can align the heading without use of the magnetometer. The INS solution will start in INS_ALIGNING status (1) and immediately proceed to INS_NAV_IS_GOOD status (3) with GPS lock for Dual GNSS and accelerated horizontal movement for single GNSS INS use.

LED Status

System status including GPS lock, INS alignment, and time synchronization are reported via the top tri-color LED. This LED can be disabled (turned off) by setting bit 0x4 of DID_FLASH_CONFIG.sysCfgBits.

LED Behavior Solution
Status #
Status Description
White 1 Solution Aligning The solution is aligning on startup
Cyan 2 Solution Alignment Complete The solution has aligned but insufficient dynamics have been completed for the variance to reach nominal conditions.
Green 3 Solution Good – NAV The solution is in Navigation mode and state estimate is good.
Blue 5 Solution Good – AHRS The solution is in AHRS mode and state estimate is good. There is no valid position or velocity data from GPS or other aiding sensor. Only the attitude states are estimated
Orange 4,6 Solution High Variance The solution is in Navigation or AHRS mode but variance (uncertainty) is high. This may be caused by excessive sensor noise such as vibration, magnetic interference, or poor GPS visibility or multipath errors. See DID_INL2_VARIANCE.
Purple Magnetometer Recalibration The system is collecting new magnetometer calibration data and requires rotation.
Cyan Fading Bootloader Waiting The bootloader has started and is waiting for communications.
Purple Fast Blink Firmware Upload The bootloader is uploading the embedded firmware.
Orange Fast Blink Firmware Verification The bootloader is verifying the embedded firmware.
Red Bootloader Failure The bootloader has experienced a failure on startup.
Can combine with behaviors above
Red pulse every 1s GPS PPS Sync The system has received and synchronized local time to UTC time using the GPS PPS signal.
Red/purple pulse every 1s RTK Base Data Received The system is receiving RTK base station data.
Purple pulse every 1s RTK Fix Status The GPS has valid RTK fix and high precision positioning

Status flags described in this section that can be observed by bitwise ANDing any of the status flag bitmasks with the corresponding status flags variable.

Status Flags

This section lists the commonly used status flags. A complete listing of status flags is available in data_sets.h.

insStatus – INS Status Flags

The INS status flags, insStatus, are found in the DID_INS1, DID_INS2, DID_INS3, and DID_SYS_PARAMS messages. Bitmasks for the insStatus flags are defined in eInsStatusFlags in data_sets.h.

Field Description
INS_STATUS_ALIGN_COARSE_MASK Position, Velocity & Attitude are usable. Variance of the state estimate are outside spec.
INS_STATUS_ALIGN_GOOD_MASK Position, Velocity & Attitude are good. Variance of state estimate are within spec.
INS_STATUS_GPS_AIDING_HEADING INS heading are being corrected by GPS.
INS_STATUS_GPS_AIDING_POS INS position and velocity are being corrected by GPS.
INS_STATUS_GPS_UPDATE_IN_SOLUTION GPS update event occurred in INS, potentially causing discontinuity in position path.
INS_STATUS_MAG_AIDING_HEADING INS heading are being corrected by magnetometer.
INS_STATUS_NAV_MODE AHRS = 0 (no position or velocity), NAV = 1
INS_STATUS_MAG_RECALIBRATING Magnetometer is recalibrating.
INS_STATUS_MAG_NOT_GOOD Magnetometer is experiencing interference.
INS_STATUS_SOLUTION_MASK 0=INS_INACTIVE – The INS is not runnning
1=INS_STATUS_SOLUTION_ALIGNING – The INS is aligning on startup
2=INS_STATUS_SOLUTION_ALIGNMENT_COMPLETE – The INS has aligned but insufficient dynamics have been completed for the variance to reach nominal conditions.
3=INS_STATUS_SOLUTION_NAV – The INS is in NAV mode and the state estimate is good.
4=INS_STATUS_SOLUTION_NAV_HIGH_VARIANCE – The INS is in NAV mode and the state estimate is experiencing high variance. This may be caused by excessive noise on one or more sensors, such as vibration, magnetic interference, poor GPS sky visibility and/or GPS multipath errors. See DID_INL2_VARIANCE.
5=INS_STATUS_SOLUTION_AHRS – INS is in AHRS mode and the solution is good. There is no valid position correction data from GPS or other aiding sensor. Only the attitude states are estimated.
6=INS_STATUS_SOLUTION_AHRS_HIGH_VARIANCE – INS is in AHRS mode and the state estimate has high variance. See DID_INL2_VARIANCE.

hdwStatus – Hardware Status Flags

The hardware status flags, hdwStatus, are found in the DID_INS1, DID_INS2, DID_INS3, and DID_SYS_PARAMS messages. Bitmasks for the hdwStatus flags are defined in eHdwStatusFlags in data_sets.h.

Field Description
HDW_STATUS_MOTION_MASK Accelerometers and Gyros are operational
HDW_STATUS_GPS_SATELLITE_RX Antenna is connected to the GPS receiver and signal is received
HDW_STATUS_STROBE_IN_EVENT Event occurred on strobe input pin
HDW_STATUS_SATURATION_MASK Acc., Gyro, Mag or Baro is saturated
HDW_STATUS_SELF_TEST_FAULT BIT has failed
HDW_STATUS_ERR_TEMPERATURE Outside of operational range
HDW_STATUS_FAULT_BOD_RESET Low Power Reset
HDW_STATUS_FAULT_POR_RESET Software or Triggered Reset

Built-in Test (BIT) Flags

Built-in test (BIT) is enabled by setting DID_BIT.state = BIT_STATE_CMD_FULL_STATIONARY (2). BIT takes about 1 second to run, and is completed when DID_BIT.state == BIT_STATE_DONE (1). All BIT tests except those related to GPS require the system to be stationary to be accurate.

hdwBitStatus – Hardware BIT Flags

Hardware BIT flags are contained in hdwBitStatus, found in the DID_BIT message. Bitmasks for the hdwBitStatus flags are defined in eHdwBitStatusFlags in data_sets.h.

Field Description
HDW_BIT_PASSED_ALL All HBIT are passed
HDW_BIT_PASSED_AHRS All Self Tests passed without GPS signal
HDW_BIT_FAILED_MASK One of the built-in tests failed
HDW_BIT_FAULT_GPS_NO_COM No GPS Signal
HDW_BIT_FAULT_GPS_POOR_CNO Poor GPS signal. Check Antenna
HDW_BIT_FAULT_GPS_ACCURACY Poor GPS Accuracy or Low number of satellites

calBitStatus – Calibration BIT Flags

Calibration BIT flags are contained in calBitStatus, found in the DID_BIT message. Bitmasks for the calBitStatus flags are defined in eCalBitStatusFlags in data_sets.h.

Field Description
CAL_BIT_PASSED_ALL Passed all calibration checks
CAL_BIT_FAILED_MASK One of the calibration checks failed

Health Monitoring

This section illustrates tests used for system health monitoring in common application.

  1. Communication Check

    To check that cabling between the unit and the application is working after initialization, expect that the initial expected packets are received within 3 seconds.

  2. Sensor Test (Must be Stationary)

    These tests are ideal for manufacturing and periodic in-field testing. Initiate by setting DID_BIT.state = 2.

Test Description
hdwBitStatus & HDW_BIT_PASSED_ALL Hardware is good
calBitStatus & CAL_BIT_PASSED_ALL Sensor calibration is good
  1. GPS Hardware Test

    Initiate by setting DID_BIT.state = 2.

Test Description
hdwBitStatus & HDW_BIT_FAULT_GPS_NO_COM No GPS serial communications.
hdwBitStatus & HDW_BIT_FAULT_GPS_POOR_CNO Poor GPS signal strength. Check antenna.
  1. GPS Lock Test
Test Description
hdwStatus & INS_STATUS_USING_GPS_IN_SOLUTION GPS is being fused into INS solution
  1. INS Output Valid
Test Description
insStatus & INS_STATUS_ATT_ALIGN_GOOD Attitude estimates are valid
insStatus & INS_STATUS_VEL_ALIGN_GOOD Velocity estimates are valid
insStatus & INS_STATUS_POS_ALIGN_GOOD Position estimates are valid
  1. System Temperature

    System temperature is available at DID_SYS_SENSORS.temp.

  2. Communications Errors

    HDW_STATUS_COM_PARSE_ERROR_COUNT(DID_SYS_SENSORS.hStatus) is the number of parsed packet errors encountered.