Onwa Marine Electronics KAP-833 - Manual (Page 34)

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The Rudder limit control is hardware preset.
There are physical limitations to the angle that the rudder can move through. If
the autopilot attempts to drive the rudder past these limits, damage to the steering
gear may occur.
An internal potentiometer is set to ensure that the KAP-833
will not drive the rudder past the set limits.
An internal control of the KAP-833 can then be used to limit the amount of
rudder travel to an even narrower range. This can be used to limit the rate of turn
of the vessel. Under normal operation the internal rudder limit control is set at
maximum.
Rudder Limit (Software Preset)
If the autopilot attempts to drive the rudder beyond its physical limits, the steering
gear may be damaged. An internal rudder limit adjustment has been set to prevent
this occurring. The internal rudder limit control can then be used to restrict the
rudder angle range even further, and is intended to be used to prevent sharp turns,
rather than protect the autopilot system.
NOTE: If the rudder feedback unit has been installed correctly, it should
not be necessary to adjust the Rudder Limits Switch Setting.
The rudder limits prevent the steering motor driving the rudder beyond its physical
(mechanical) stops. The limit switch is set so that the limit display comes on
before the rudder reaches the stops.
These are two display symbols P_L (port limit), S_L (starboard limit) indicating
the state of the rudder limit circuits...
The port limit P_L display will come on when the rudder position is
further to port than the limit set by the rudder limit port setting. This
will cause any port drive command to be ignored and turn off the port
drive light on the front panel.
The starboard limit S_L functions in same way rudder angles to starboard.
NOTE: THE RUDDER LIMITS ARE FACTORY SET TO
APPROXIMATELY 25 DEGREES. IF THE RUDDER
FEEDBACK HAS BEEN INSTALLED CORRECTLY, THE
P_L AND S_L SYMBOLS SHOULD DISPLAY WHEN THE
RUDDER IS MOVED PORT PORT OR STARBOARD BY 25
DEGREES.
VR101(RUDLIM)
Rudder Limit
6 4