Warning: Do not use the DCT turn pattern unless the seabed is suitable.
Do not use it in rocky waters where the depth is varying significantly over a
small area.
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Note: If depth data is lost during DCT the autopilot will automatically switch to auto
mode.
It is recommended to turn on the AP Depth Data Missing alarm when using DCT. When
this alarm is activated an alarm will be raised if the depth data is lost during DCT.
To initiate a DCT turn
• Steer the boat to the depth you want to track, and in the direction of the depth contour
• Activate auto mode, then select depth contour tracking while monitoring the depth
reading
• Select the port or starboard button to initiate the depth contour steering to follow the
bottom sloping to starboard or to port
Port option
(depth decreases to port)
Starboard option
(depth decreases to starboard)
Turn variables
• Ref. depth: this is the reference depth for the DCT function. When DCT is initiated the
autopilot reads the current depth and set this as the reference depth. The reference depth
can be changed when the function is running
• Depth gain: this parameter determines the ratio between commanded rudder and the
deviation from the selected depth contour. The higher depth gain value the more rudder
is applied. If the value is too small it will take a long time to compensate for drifting off the
set depth contour, and the autopilot will fail to keep the boat on the selected depth. If the
value is set too high the overshoot will increase and the steering will be unstable.
• CCA: the CCA is an angle that is added to or subtracted from the set course. With this
parameter you can make the boat yaw around the reference depth with s movements.
The larger the CCA the bigger yawing will be allowed. If the CCA is set to zero there is no
S-ing.
Operating a professional autopilot system
If the MFD system is connected to a professional autopilot system, the MFD can be used to
operate the autopilot.
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Note: The MFD cannot be used to configure or commission a professional autopilot
system.
Autopilot| NSS evo3S Operator Manual
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