Hemisphere GPS P306, Integrator Manual

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P306/P307 Integrator’s Guide Appendix B-Troubleshooting Page 33 of 39
Use the following checklist to troubleshoot anomalous P306/P307 operation. Table B-1 provides a list of
issues with possible solutions. Refer to
Appendix C , “Technical Specifications” if necessary.
Table B-1: Troubleshooting
Issue Possible Solution
What is the first thing I do if I
have a problem with the
operation of the P306/P307? Try to isolate the source of the problem. Problems are likely to fall within one
of the following categories:

Power, communication, and configuration

GNSS reception and performance

Beacon reception and performance

SBAS reception and performance

External corrections

Installation

Shielding and isolating interference

It is important to review each category in detail to eliminate it as a
problem.
No data from the P306/P307
No communication
No valid data 
Check receiver power status (this may be done with an ammeter)

Verify P306/P307 is locked to a valid GNSS signal (this can often be
done on the receiving device or by using SLXMon)

Verify that P306/P307 is locked to GNSS satellites (this can often be
done on the receiving device or by using SLXMon)

Check integrity and connectivity of power and data cable connections
Random binary data from the
P306/P307

Verify that the RTCM or Bin messages are not being accidentally
output (send a $JSHOW command)

Verify that the baud rate settings of P306/P307 and remote device
match.

Potentially, the volume of data requested to be output by the
P306/P307 could be higher than the current baud rate supports. Try
using 19200 or higher for the baud rate for all devices
No GNSS lock 
Check integrity of antenna cable

Verify antenna’s view of the sky

Verify the lock status and signal to noise ratio of GNSS satellites (this
can often be done on the receiving device or by using SLXMon)
No DGPS position in external
RTCM mode 
Verify that 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
(the “ground” pin and pinout must be connected, and from the
“transmit” from the source must connect to the “receiver” of the RTCM
input port)
Non-DGPS output 
Verify P306/P307 SBAS and lock status (or external source is locked)