Rikaline 24A User Manual page 10

GPS Receiver Board
Appendix A
The GPS-24 / 24A interface protocol is based on the National Marine Electronics Association's NMEA 0183
ASCⅡ interface specification, which is defined in NMEA 0183, Version 3.0 and the Radio Technical
Commission for Maritime Services (RTCM Recommended Standards For Differential Navstar GPS Service,
Version 2.1, RTCM Special Committee No.104).
A.1 NMEA Transmitted Messages
The GPS-24 / 24A outputs data in NMEA-0183 format as defined by the National Marine Electronics
Association (NMEA), Standard.
The default communication parameters for NMEA output are 9600 baud, 8 data bits, stop bit, and no parity.
Table A-1 NMEA-0183 Output Messages
NMEA Record Description
Global positioning system fixed data
GPGGA
Geographic position- latitude/longitude
GPGLL
GNSS DOP and active satellites
GPGSA
GNSS satellites in view
GPGSV
Recommended minimum specific GNSS data
GPRMC
Course over ground and ground speed
GPVTG
Date & Time
GPZDA
A.1.1 Global Positioning System Fix Data (GGA)
$GPGGA,161229.487,3723.2475,N,12158.3416,W,1,07,1.0,9.0,M, , , ,0000*18
Table A-2 GGA Data Format
Name
Message ID
UTC Time
Latitude
N/S Indicator
Longitude
E/W Indicator
Position Fix Indicator
Satellites Used
HDOP
MSL Altitude
Units
Geoid Separation
Units
Age of Diff. Corr.
Diff. Ref. Station ID
Checksum
<CR> <LF>
Table A-3 Position Fix Indicator
Value
0 0 Fix not available or invalid
1 GPS SPS Mode, fix valid
2 Differential GPS, SPS Mode, fix valid
3 GPS PPS Mode, fix valid
A.1.2 Geographic Position with Latitude/Longitude (GLL)
Rikaline International Corp.
Tel: ++886 2 2370 4688 Fax: ++886 2 2370 4686 E-Mail:
GPS-24 / 24A Operating Manual
Software Interface
Example Units
$GPGGA
161229.487
3723.2475
N
12158.3416
W
1
07
1.0
9.0 Meters
M Meters
Meters
M Meters
second
0000
*18
10F, 64, Kang-Din Road, Taipei 108, Taiwan
Description
GGA protocol header
Hhmmss.sss
Ddmm.mmmm
N=north or S=south
dddmm.mmmm
E=east or W=west
See Table 5-3
Range 0 to 12
Horizontal Dilution of Precision
Null fields when DGPS is not used
End of message termination
Description
Specifications subject to change without prior notice
info@rikaline.com.tw
Rikaline
Web: www.rikaline.com.tw
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