Simrad NSS evo2 series Installation Manual page 33

Rudder deadband
This parameter is used to prevent the rudder from hunting. The reading is obtained from the
Rudder test which optimizes the deadband to the speed of the boat and the pressure on the
rudder.
If the auto-setting does not perform properly due to high inertia from the wheel or a loose
steering gear, it can be adjusted manually. Find the lowest possible value that will prevent the
rudder from continuous hunting. A wide deadband will cause inaccurate steering.
¼ Note:
The rudder deadband setting is not available when the autopilot is configured for
Virtual Rudder Feedback.
Seatrials
A seatrial can only be performed if the dockside settings are completed and confirmed. The
seatrial must always be performed in open waters at a safe distance from other traffic.
¼ Note:
You can switch the autopilot to standby mode and take manual control of the boat at
any time during the seatrial by pressing the 'STBY/AUTO' key.
The following seatrial calibration should be done:
•
Compass calibration; used to automatically compensate for on-board magnetic interference
•
Compass offset adjustment, used to compensate for a fixed offset in the final heading
readout
•
Wind vane offset is to compensate for a wind vane that is not mounted facing in exactly the
same direction as the bow of the vessel (dead ahead)
•
Boat speed calibration
•
Transition HI/LO speed setting (the speed at which you want to change the set of steering
parameters)
•
Automatic tuning of the steering parameters
•
Setting the seastate filter
•
'Sailboat Setup' menu items
Compass calibration
Before the compass calibration is started, make sure that there is enough open water around
the vessel to make a full turn.
The calibration should be done in calm sea conditions and with minimal wind to obtain good
results. Follow the on-screen instruction, and use about 60-90 seconds to make a full circle.
During the calibration, the compass will measure the magnitude and direction of the local
magnetic field.
•
If the local magnetic field is stronger than the earth's magnetic field (the local field is reading
more than 100 %), the compass calibration will fail.
•
If the local field is reading more than 30 %, you should look for any interfering magnetic
objects and remove them, or you should move the compass to a different location. The
(local) field angle will guide you to the local interfering magnetic object.
¼ Note:
Calibration must be made on the compass that is active for the autopilot. If the com-
pass is not possible to initiate calibration from the device list on the NSS evo2, refer to the
compass' own instructions regarding calibration.
¼ Note:
In certain areas and at high latitudes the local magnetic interference becomes more
significant and heading errors exceeding ±3° may have to be accepted.
Compass mounting offset
After compass calibration, the difference (if any) between the compass lubber line and the
boat's center line should be compensated for.
1.
Find the bearing from the boat position to a visible object. Use a chart or a chart plotter
2.
Steer the boat so that the center line of the boat is aligned with the bearing line pointing
towards the object
2.
Change the offset parameter so that the bearing to the object and the compass readout
becomes equal.
Software setup | NSS evo2 Installation Manual
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