CodaOctopus F175 MOTION - Chapter 8 Troubleshooting

Troubleshooting
Copyright © 2013 Coda Octopus Products Ltd
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F175 MOTION Sensor - Trimble SPS361/SPS461 Integration
8 Troubleshooting
The F175 System gets different information from the different GSOF messages that the
Trimble SPS361/SPS461 outputs. Table below lists the information decoded in each message.
GSOF Message
Data Rate
Description
Position and Time
10 Hz
Time, Position Mode, Velocity
Mode, Number of Satellites
DOP values
1 Hz
HDOP, VDOP, PDOP
Position WGS84 (LLH)
5 Hz
Latitude, Longitude, Altitude
Velocity and Header data
10 Hz
Velocity North, East and
Down
Error Covariance data
5 Hz
Position Accuracy
Current Time/UTC Offset
1 Hz
UTC Offset
In addition, the internal GPS must have found time and position so that it can accurately
synchronise the IMU to the external GPS. An antenna must be fitted to the Primary GPS port in
order to get the F175 System to work.
To trouble shoot the interface between the F175 System and the external GPS receiver, refer
to the table below.
Problem
Description
The system appears to work even though the
External GPS is not connected
The F175 System is configured to use the
Internal GPS, which is not as accurate.
The GPS LED is off
There is no data being received from the
Trimble SPS361/SPS461. (If corrupt data was
being sent then the LED would be red or
flashing red).
The “External GNSS Data Skipped” field is
increasing
Check that the baud rate is correct. Check that
GSOF messages, not NMEA messages, are
being output by the Trimble SPS361/SPS461.
The software shows that there are some
Skipped Data from the External GNSS
This is normal. As long as the number is not
increasing then there is nothing to worry
about.
The Position Mode is “None”
The “GSOF Time and Position” message is not
being received.
The Velocity Mode is “None”
The “GSOF Time and Position” message is not
being received.