3.3.2.4. MAHRS Diagnostics

3.3.2.4.1. TSS1 message

  • The TSS1 data string contains 27 characters in five data fields.

  • The acceleration fields contain ASCII-coded hexadecimal values. Horizontal acceleration uses units of 3.83cm/s2 in the range zero to 9.81m/s2. Vertical acceleration uses units of 0.0625cm/s2 in the range –20.48 to +20.48m/s2.

  • The motion measurements contained in the data string will be in real time, valid for the instant when the System begins to transmit the string. _ Motion measurements include ASCII-coded decimal values.

  • Heave measurements are in cm in the range –99.99 to +99.99 metres. Positive heave is above datum.

  • Roll and pitch measurements are in degrees in the range –90.99° to +90.99°. Positive roll is port-side up, starboard down. Positive pitch is bow up, stern down.

3.3.2.4.2. Interpreting the Status Flag

“U” UNAIDED MODE – SETTLED CONDITION

The System is operating without any input from a gyrocompass, a GPS receiver or a Doppler log.

“u” UNAIDED MODE – SETTLING

The System is operating as above but is still awaiting the end of the 3 minutes settling period after power- on or a change of mode or heave bandwidth.

“G” GPS AIDED MODE – SETTLED CONDITION

The System is receiving and using velocity aiding signals from a GPS receiver or a Doppler log.

“g” GPS AIDED MODE – SETTLING

The System is receiving velocity aiding signals from a GPS receiver or a Doppler log, but is still awaiting the end of the 3 minutes settling period after power-on or a change of mode or heave bandwidth.

“H” HEADING AIDED MODE – SETTLED CONDITION

The System is receiving and using heading aiding signals from a gyrocompass.

“h” HEADING AIDED MODE – SETTLING

The System is receiving heading aiding signals from a gyrocompass but is still awaiting the end of the 3 minutes settling period after power-on or a change of mode or heave bandwidth.

The gyrocompass may take several hours to settle after it has been powered-on. During this time, gyro- compass aiding of the System will not be perfect. The status flag does NOT indicate this condition.

“F” FULL AIDED MODE – SETTLED CONDITION

The System is receiving and using aiding signals from a gyrocompass and from a GPS receiver or a Doppler log.

“f” FULL AIDED MODE – SETTLING

The System is receiving aiding signals from a gyrocompass and a GPS receiver or a Doppler log, but is still awaiting the end of the 3 minutes settling period after power-on or a change of mode or heave bandwidth.

Examples

example warning TSS1 message:


:023D97 -0043h-0031  0126
:003D35 -0042h-0091  0133
:053D9B -0028h-0140  0087
:053D2E  0018h-0215  0090

example good TSS1 message:

:003D43  0000F-0082  0114
:003D44  0000F-0082  0114
:003D3E  0000F-0018  0116
:003D41  0000F-0020  0116
:003D41  0000F-0019  0115
:003D32  0000F-0009  0112
:003D3E  0000F-0006  0110
:003D44  0000F-0041  0124