5.3.4 Failure and alarm status of sensor
In the case of any failure or alarm status received from the position-fixing sensor or the heading sensor in use:
.1 an alarm should be generated at the track control system;
.2 the system should provide guidance of the user to a safe steering mode; and
.3 a back-up navigator alarm should be given if a failure or alarm status is not acknowledged by the officer of the watch within 30 seconds.
Fall-back procedures consequential to the failure and alarm conditions are states in section 9.
5.3.5 Use of faulty signals
It should not be possible to select any sensor signal tagged with a fault or alarm status.
5.3.6 Cross track alarm
A cross track alarm, should be Provided when the actual position deviates from the track beyond a preset cross track limit.
5.3.7 Course difference signal
An alarm should be given if the actual heading of the ship deviates from the track course beyond a preset value.
5.3.8 Low speed alarm
If speed through the water is lower than a predefined limit necessary for steering the ship an alarm should be given.
6. Ergonomic criteria
6.1 Operational controls
6.1.1 Controls for track control
Means should be provided to:
.1 accept or calculate the course between subsequent waypoints; and
.2 adjust radius or rate of turn, all track control related limits, alarm functions and other control parameters.
