Seiwa Si-Tex Vector 3D GPS - Manual (Page 36)

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Vector 3D User Guide
Table A-1: Troubleshooting (continued)
Symptom Possible Solution
No SBAS lock • Verify the 3D has a clear view of the sky
• Verify the lock status of SBAS satellites (this can be done
with SI-TEX Toolkit - monitor BER value)
• SBAS lock can only get if you are in an appropriate SBAS
region (currently, there is limited SBAS availability in the
southern hemisphere)
• Set SBAS mode to automatic with the $JWAASPRN,AUTO
command
No heading or incorrect
heading value • Check CSEP value is fairly constant without varying more
than 1 cm (0.39 in)—larger variations may indicate a high
multipath environment and require moving the receiver
location
• Recalibrate the tilt sensor with $JATT,TILTCAL command
if heading is calculated then lost at consistent time intervals
• Heading is from primary GPS antenna to secondary GPS
antenna, so the arrow on the underside of the
3D should be
directed to the bow side
• $JATT,SEARCH command forces the 3D to acquire a new
heading solution (unless gyro is enabled)
• Enable GYROAID to provide heading for up to three
minutes during GPS signal loss
• Enable TILTAID to reduce heading search times
• Monitor the number of satellites and SNR values for both
antennas within SI-TEX Toolkit—at least four satellites
should have strong SNR values
• Potentially, the volume of data requested to be output by the
3D could be higher than the current baud rate supports (try
using 19200 as the baud rate for all devices or reduce the
amount of data being output)
No DGPS position in external
RTCM mode • Verify the baud rate of the RTCM input port matches the
baud rate of the external source
• Verify the pinout between the RTCM source and the RTCM
input port (transmit from the source must go to receive of the
RTCM input port and grounds must be connected)
• Ensure corrections are being transmitted to the correct
port—using the $JDIFF,PORTC command on Port A will
cause the receiver to expect the corrections to be input
through Port C