Appendix; Advice On Operation; Warning; Nmea Sentences Received - Simrad AP14 Manual

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Appendix

7.1 Advice On Operation

• When making course changes, be aware of the effect of a large course change on the boat, espe-
cially when travelling at high speed - the AP14 will respond very quickly to any instructions, so it
is advisable to reduce speed before changing course. This should particularly be remembered
when approaching a waypoint in Nav Mode - pressing Nav to head for the next waypoint could
result in a sudden and severe course change. This is one of the reasons that a constant vigil and
awareness of the situation must be maintained (see warning below).
• The Gain setting is critical on a high speed vessel like a power boat, because it affects the reac-
tion speed of the autopilot. As you become more familiar with the operation of the AP14 and how
your own boat handles, it should be possible to tailor the Gain settings to suit the speed of the boat
and the conditions it is cruising under.

7.2 Warning

The AP14 is a highly advanced autopilot, and a valuable aid to enjoyable cruising. However, it
would be a mistake to become complacent. Like all electronic navigational equipment, it is an aid
to navigation and should not be used as a substitute for conventional navigational practice.
Remember - Maritime Law* requires that you keep a good look out at all times.

7.3 NMEA Sentences Received

The NMEA0183 information required for full functionality while in Nav Mode is as follows -
Cross track error
Bearing to destination waypoint
Arrival at waypoint indication
This information is extracted from the following NMEA0183 sentences -
XTE Cross Track Error
BWC Bearing & Distance To Destination Waypoint (Great Circle)
Bearing & Distance To Destination Waypoint (Rhumb Line)
BWR
Cross Track Error, Bearing To Destination Waypoint and Arrival At Waypoint
APA
APB Cross Track Error, Bearing To Destination Waypoint and Arrival At Waypoint
RMA Boat Speed
Cross Track Error, Bearing, Distance and Arrival At Arrival Waypoint
RMB
Boat Speed
RMC
NOTE - The Cross Track Error (XTE) information has a maximum value of 1.27 Nautical Miles. If
the XTE exceeds this while using Nav Mode, the AP14 will sound an alarm, exit Nav Mode and
return to Compass Auto Mode.
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*IMO International Regulations for Preventing Collisions at Sea, Part B Rule 5 (1972)

7.4 Fault Finding

Symptom
Pilot will not enter Auto mode. Rudder limits not entered*.
Rudder limits configuration
failed*.
Faulty connection to SLF12*
Faulty connection to SHS12.
Fault with SCP12* / SRD12†.
Low supply voltage to Drive
Autopilot drops back into
Standby Mode. Unit or Course Computer*.
Cannot select Nav Mode Navigational data not avail-
able.
Incorrect NMEA format or sen-
tences are being transmitted.
Destination not programmed
in navigator.
Autopilot will not allow rudder Power cable gauge too small.
travel limits to be set*. SLF12 incorrectly wired or
installed.
Pump not primed or airlocked
Buttons not pressed properly
Autopilot does not maintain an SHS12 compass has not been
accurate course in Auto Mode. calibrated.
SHS12 compass is encounter-
ing magnetic interference.
• If the boat's magnetic
compass is being used as a ref-
erence, it is more likely that
this is inaccurate unless it has
being recently swung.
Compass will not auto calibrate
Turn rate too fast/slow
Conditions too rough
Deviation detected is too large
Boat's course is unstable when
Gain setting is incorrect for
in Auto mode.
boat's speed or type.
* - AP14H only † – AP14R only
Probable Cause
Remedy
Enter rudder limits* (see 6.3)
Check all connections.
Replace fuse.
Check battery charge.
Check all electrical connec-
tions and supply cables.
Check NMEA connections.
Refer to section 7.3 for correct
NMEA0183 sentence formats.
Check recommended cable
sizes (Fig 4.17)
Check SRP12 & SLF12 wiring
and installation.
Prime pump & bleed system.
Refer to section 6.4 to calibrate
the compass to compensate for
magnetic deviation.
Check area around SHS12 for
magnetic objects (loudspeak-
ers, heavy current carrying
cables etc). Minimum com-
pass safe distance is 1m (3 Ft).
Check course against other
reference (handbearing com-
pass etc) and swing boat's
compass if necessary.
Flashing LEDs
Port/Starboard keys indicate
if turn rate is too fast or slow.
Calibration should be attempt-
ed in calm conditions
Check area around compass
for metallic objects/speakers
etc (min safe distance - 1m/3ft)
Adjust Gain to suit boat's
speed: Low Speed=High Gain
High Speed=Low Gain
above
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