Product specifications

Crescent Integrator’s Manual 52
grounds must be connected)
• There is only differential positioning enabled for
the Primary receiver and RTCM corrections should
be input to the Primary receiver (either Port A or
B)
• Ensure corrections are being transmitted to the
correct port. Using the $JDIFF,OTHER command on
Primary Port A will cause the receiver to expect the
corrections to be input through Primary Port B
Non-differential GPS output • Verify SBAS and beacon lock status (or external
source is locked)
• Confirm baud rates match an external source
correctly
• Issue a $JDIFF<CR><LF> command and see if the
expected differential mode is in fact the current
mode
• There is only differential positioning enabled for
the Primary receiver, and the Secondary should
only have GPS position
No heading or incorrect
heading values
• Ensure that the antennas are connected to the
proper ports. J1000 and J2000 are for the Primary
and Secondary antennas, while J410 is for an
optional beacon antenna connection
• Heading is from Primary to Secondary antenna, so
the Secondary antenna should be towards the
bow, and Primary towards the stern
• Use the heading output from the Primary receiver
(either through Port A or B) and not from the
Secondary receiver
• Check the measurement of the antenna
separation. The Measured (MSEP) and Calculated
(CSEP) values are in metres, and should agree to
within 1 centimetre. CSEP will continuously
change, so you should average this reading over a
few minutes to obtain an approximate value
• Check CSEP value is fairly constant without varying
more than 1 cm. Larger variations may indicate a
high multipath environment and require moving
the antenna locations
• Reduce antenna separation – we recommend that
the separation between the antennas remain below
2 metres for accurate and timely heading reading
output
• $JATT,SEARCH command forces the Vector to
acquire a new heading solution. This should also
be used after entering a new MSEP value
• Disable MAGAID – this feature requires precise
calibration, and if improperly performed this will
affect heading output. This sensor requires
recalibration each time anything in the magnetic
environment changes
• Enable GYROAID as this will give heading for up to
3 minutes in times of GPS signal loss
• Enable TILTAID to reduce heading search times
• Check the applications on the Primary and
Secondary receivers using the $JAPP query. The
Primary receiver should answer
$JAPP,ATTITUDM,ATTITUDM and the Secondary
will respond with $JAPP,ATTITUDS,ATTITUDS
• Monitor the number of satellites and SNR values
for both antennas. At least 3 satellites should have
SNR values above 20
• Antenna connectors should both be facing in the
same direction