Specifications

24
NAVIGATION INTERFACE
If the autopilot is being interfaced to a
navigation device with several NMEA
outputs, determine the type of output
formats available from its data sheets.
The 1001 autopilot will only support
NMEA 0183 data format and therefore
that format must be selected. If your
navigation device only outputs 0180 or
0182 formats, please consult with
ComNav service personnel to receive
software that will support these older
style formats.
NMEA 0183
The standard baud rate for the 0183 data
format is 4800 baud.
This data format was developed to allow
a number of pieces of electronic
equipment on the vessel to communicate
with each other. It consists of a large
number of data 'sentences' which can
transmit anything from the vessel's water
speed to its present position from one
device to another.
A data sentence consists of a two letter
identification of the sending device,
followed by a three letter identification of
the data sentence, followed by the
corresponding information.
The autopilot can understand a number
of data sentences that contain steering
or speed information. The autopilot
ignores the two letter device identifier,
and only looks for the three letter
sentence identifier, so it will receive
information from any Nav Device which
transmits the correct data sentences.
Some NMEA 0183 data sentences
supply heading from the beginning of
track to the end of the track, which
remains constant until the Nav Device
sequences to the next waypoint. This is
the best type of Heading To Steer
information, as it prevents the wandering
which may occur when the vessel is
close to the destination waypoint as
described earlier.
Depending on the type of Nav device
and how it is configured, the autopilot
may sound its alarm and display 'Arr'
when the vessel is close to a waypoint.