Ret-3570lp user manual, Software interface – RoyalTek RET-3570LP User Manual
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RET-3570LP User Manual
2. Software Interface
NMEA V3.0 Protocol
Its output signal level is TTL: 38400 bps (default), 8 bit data, 1 stop bit and no parity. It supports the
following NMEA-0183
Messages: GGA, GSA, GSV, RMC .
NMEA Output Messages: the Engine board outputs the following messages as shown in Table 1:
Table 1 NMEA-0183 Output Messages
NMEA Record
Description
GGA
Global positioning system fixed data
GSA
GNSS DOP and active satellites
GSV
GNSS satellites in view
RMC
Recommended minimum specific GNSS data
GGA-Global Positioning System Fixed Data
Table 2 contains the values of the following example:
$GPGGA, 161229.487, 3723.2475, N, 12158.3416, W, 1, 07, 1.0, 9.0, M, , , ,0000*18
Table 2 GGA Data Format
Name Example
Units Description
Message ID
$GPGGA
GGA protocol header
UTC Position
161229.487
hhmmss.sss
Latitude 3723.2475
ddmm.mmmm
N/S Indicator
N
N=north or S=south
Longitude 12158.3416
Dddmm.mmmm
E/W Indicator
W
E=east or W=west
Position Fix Indicator
1
See Table 2-1
Satellites Used
07
Range 0 to 12
HDOP
1.0
Horizontal Dilution of Precision
MSL Altitude
9.0
meters
Units M
meters
Geoid Separation
meters
Units M
meters
Age of Diff. Corr.
second Null fields when DGPS is not
used
Diff. Ref. Station ID
0000
Checksum *18
<
CR><LF>
End of message termination