GLOBALSAT ET-314 GPS Engine Board - Manual (Page 19)

ET-314AC
High Performance GPS Engine Board
2010/4/1
- 19 -
Table B-8 LLA Navigation Initialization Data Format
Name Example Unit Description
Message ID $PSRF104 PSRF104 protocol header
Lat 37.3875111 degrees Latitude + = North (Range 90 to -90)
Lon -121.97232 degrees Longitude + = East (Range 180 to -180)
Alt 0 meters Altitude position
ClkDrift 96000 Hz Clock Drift of the Receiver1
TimeOfWeek 237759 sec GPS Time Of Week
WeekNo 1946 Extended GPS Week Number
ChannelCount 12 Range 1 to 12
ResetCfg 1 See Table B-9
Checksum *07
End of message termination
Use 0 for last saved value if available. If this is unavailable, a default value of 96,250 Hz is used.
Table B-9 Reset Configuration Bit Map
Bit Description
0☆ Data valid flag: 1 = Use data in ECEF X, Y, Z, Clock Offset, Time of Week and Week
number to initialize the receiver; 0 = Ignore data fields
1 Clear ephemeris from memory: blocks Snap or Hot Start from occurring
2 Clear all history (except clock drift) from memory: blocks Snap, Hot, and Warm Starts
3 Factory Reset: clears all GPS memory including clock drift. Also clears almanac stored
in flash memory
4 Enable Nav Lib data (YES = 1, NO = 0) ★
☆ For software that does not support initialized data (GSW3, GSWLT3, SiRFXTrac) setting this
bit may cause unpredictable results. Do not attempt to use initializing data.
★ If Nav Lib data are enabled, the resulting messages are enabled: Clock Status (Message ID 7),
50BPS (Message ID 8), Raw DGPS (Message ID 17), NL Measurement Data (Message ID 28),
DGPS Data (Message ID 29), SV State Data (Message ID 30), and NL Initialized Data
(Message ID 31). All messages sent at 1 Hz. If SiRFDemo is used to enable Nav Lib data, the
bit rate is automatically set to 57600 by SiRFDemo.