Health monitoring system
The MRU health is monitored with the NORSUB STATUS bits (output variable n.1007), which is a LSB word (4 bytes, U32). The status bits can also be reconstructed from other output variables such as 1091 STATUS_A (first and second STATUS bytes), 1092 STATUS_B (third and fourth STATUS bytes), 1093 STATUS_1 (first STATUS byte), 1094 STATUS_2 (second STATUS byte), 1095 STATUS_3 (third STATUS byte), 1096 STATUS_4 (fourth STATUS byte).
The default and initial value for all status bits is 0. The bits are set to 1 after the corresponding parameter checks have completed successfully. The status bits are divided in 5 categories; system, sensor, environment, algorithm and aiding in addition to the Main category which is an aggregate of all other status bits. If MAIN_OK is 1, there are no warnings, no errors and no detected degradation in the performance.
BIT | PARAMETER | DESCRIPTION | CATEGORY | |||
|---|---|---|---|---|---|---|
STATUS (1007) | STATUS_A (1091) | STATUS_1 (1093) | 0 | MAIN_OK | 1 = no errors or warnings, initialization done. Everything OK. | MAIN |
1 | MAIN_HEALTH | 1 = no serious errors in sensor, algorithm or system. | ||||
2 | SYSTEM_OK | 1 = system operates normally. | SYSTEM | |||
3 | SYSTEM_HEALTH | 0 = system error. Restart required. | ||||
4 | SYSTEM_TIME_SYNC | 1 = time synchronized. | ||||
5 | SYSTEM_CLOCK_SYNC | 1 = clock synchronized. | ||||
6 | SYSTEM_CPU_OK | 1 = CPU load and memory are OK | ||||
7 | SENSOR_OK | 1 = IMU is OK. | SENSOR | |||
STATUS_2 (1094) | 8 | SENSOR_HEALTH | 0 = IMU is malfunctioning or broken. Repair or replace MRU. | |||
9 | SENSOR_LIMITS | 0 = IMU sensors are saturated. | ||||
10 | ENV_VIBRATION | 1 = environmental vibration levels are OK. | ||||
11 | ENV_TEMPERATRURE 1 | 1 = environmental temperature is OK. | ||||
12 | ALG_OK | 1 = MRU algorithms are OK. | ALGORITHM | |||
13 | ALG_HEALTH | 0 = MRU algorithms are unstable. Restart recommended. | ||||
14 | ALG_OBS_INIT | 1 = initialization of observer. | ||||
15 | ALG_HEADING_INIT | 1 = Initialization of heading. | ||||
STATUS_B (1092) | STATUS_3 (1095) | 16 | ALG_ROLLP_OK | 1 = roll/pitch are OK. | ||
17 | ALG_ROLLP_HEALTH | 0 = roll/pitch are saturated/unstable. Restart recommended. | ||||
18 | ALG_HEAD_OK | 1 = heading is OK. | ||||
19 | ALG_HEAD_HEALTH | 0 = heading is saturated/unstable. Restart recommended. | ||||
20 | ALG_SURGES_OK | 1 = surge/sway are OK. | ||||
21 | ALG_SURGES_HEALTH | 0 = surge/sway saturated/unstable. Restart recommended. | ||||
22 | ALG_HEAVE_OK | 1 = heave is OK. | ||||
23 | ALG_HEAVE_HEALTH | 0 = heave is saturated or unstable. Restart recommended. | ||||
STATUS_4 (1096) | 24 | AID_POS_RECEIVED | 1 = external position aiding is received | AIDING | ||
25 | AID_VEL_RECEIVED | 1 = external velocity aiding is received. | ||||
26 | AID_HEAD_RECEIVED | 1 = external heading aiding is received | ||||
27 | AID_POS_VALID | 1 = position aiding is valid and used in the observer | ||||
28 | AID_VEL_VALID | 1 = velocity aiding is valid and used in the observer. | ||||
29 | AID_HEAD_VALID | 1 = heading aiding is valid and used in the observer. | ||||
30 | AID_VERTICAL_VALID | 1 = vertical position is valid and used in the observer | ||||
31 | AID_HORIZONTAL_VALID | 1 = horizontal position is valid and used in the observer. |
All status bits categories have two main status bits; OK and HEALTH. If OK is 1, then everything is working properly, and it is safe to use the output data. If OK is 0, the performance may be compromised, and the user should wait until performance has returned to normal. If HEALTH is 0, there may be sensor errors, bad environment or other errors which requires restart, repair or replacement of the MRU.