Heading Monitor; Off Heading - Raytheon NautoPilot NP 5100 Operator's Manual

1.3.5

Heading Monitor

The "Heading Monitor" function monitors the heading from a Gyro compass and a Mag-
netic compass.
The monitoring threshold is set via the "Page" function
(Page Limit Heading Monitor) at the initial display. It allows settings from 5 to 30 in
increments of 1.
The the difference between Gyro heading and magnetic heading exceeds the preset
threshold, an alert is generated.
During a heading change manoeuvre this function is automatically paused, due to the
inert behaviour of the Magnetic compass.
For switching on or off the "Heading Monitor" refer to Installation Manual, chapter on
"Heading Monitor".
1.3.6

OFF Heading

This function compares the actual heading value against the set heading value.
There is an alarm if the limit between set heading and actual heading exceeds a pre--ad-
justed value (Page Limit OFF Heading). See also section 2.3.6.4.
The possible range for pre--adjusted OFF Heading value 5 to 30 (in increments of 1).
The alarm is suppressed for a calculated time after a heading change manoeuvre (cal-
culation is based on RAD or RoT time window).
The time window is calculated from the difference in the desired heading and the
preselected turning rate.
If, during the heading change manoeuvre, the ship reaches the heading alarm threshold
within the time window, no alarm is triggered.
Note:
The desired value for the rate of turn (RoT) depends on the physical characteristics of
the ship. The ship should be able to perform the turning value. Desired rates of turn
exceeding the turn capability of the ship result in the OFF heading alarm being triggered
before the ships heading reaches the desired Set Heading.
This effect also occurs if the rudder limit is adjusted too close, so the selected RAD/
RoT--limit is not achievable.
4002.DOC010102
OPERATION
NautoPilot 5000 Series
10
Edition: September 2014