Onwa Marine Electronics KAP-833 - Manual (Page 11)

The GPS unit must then be commanded to go to a waypoint, or to follow
a line joining two or more waypoints (called a route).
This unit will then send information to the autopilot from which can be
calculated the course-to-steer. If several waypoints are linked together into
a single route, and the GPS unit is set to
auto-sequence between them,
and an arrival zone of more than 0.1 NM (Nautical Miles) is set so that
the GPS can detect when the vessel has reached a waypoint, then the
KAP-833 will be able to steer from each waypoint to the next without
intervention.
If only the XTE information is available from your GPS unit then your
vessel must be on track, and heading in the correct direction before
engaging the GPS mode, and the auto-sequencing feature is not available.
Remember:
Prior to engaging GPS mode, a route must be programmed into the GPS
for the Autopilot to follow.
No GPS Data Alarm
If the autopilot is not receiving valid information while in GPS Mode, the
No GPS Data alarm will sound, and the GPS light will blink. This could
be caused by:
Incorrect wiring of the GPS to the KAP-833.
Incorrect data output from the GPS unit.
No route set up or selected in the GPS unit.
No location fix at the GPS unit.
See also Alarms in the Operation section of this manual.
The bearings generated by the GPS unit must correspond to the bearings the
KAP-833 is receiving from its magnetic compass. The greater the difference
between these bearings, the less accurate will the be GPS Mode steering.
Ensure that the GPS unit has the correct magnetic correction factor.
Ensure that the KAP-833 compass is correctly aligned and installed.
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