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G.2 serial port outputs – KVH Industries TracVision G4 User Manual

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TracVision G4 Technical Manual

G.2

Serial Port Outputs

Serial ports #1 and #2 may be individually programmed
to output any of the message formats described on the following
pages. Up to four NMEA 0183 listening devices can be connected
to each of the serial ports. Serial Port #1 also has a pass-through
duplicate port.

NMEA

The NMEA message format conforms to the
NMEA 0183 version 2.20 standard for message
structure.

KVH RS-422

The KVH message format is an RS-422 message
format giving stabilized pitch, roll, and yaw data.
Data output from Port 1 will be at 4800 baud while
data from Ports 2 and 3 will be at 9600 baud; this
message may be used in any device capable of
receiving this data rate.

Cetrek Proprietary

The Cetrek proprietary message format is a
stabilized heading output for use with Cetrek
autopilots.

Each serial port can be independently programmed to output data
at a rate of 1 Hz to 20 Hz, selectable in 1 Hz increments. The default
data rate is 10 Hz.

NMEA1 Magnetic Heading (HDM)

Communication:

4800 baud, 1 start bit, 8 data bits, 1 stop bit,
no parity

Update rate:

Selectable at 1 to 20 Hz (10 Hz default)

Sentence type:

$HCHDM,XXX.X,M,* hh

Sentence breakdown:

HCHDM

NMEA talker and sentence ID

XXX.X

Stabilized magnetic heading in
degrees and tenths

M

Magnetic heading, ASCII hex
0x4D

*

ASCII hex 0x2A

hh

Checksum

cr

Carriage return, ASCII hex 0x0D

lf

Line feed, ASCII hex 0x0A

Table G-1

NMEA1 Magnetic

Heading Output

Port 3 is not used if GyroTrac is
connected to the TracVision
antenna.