beautypg.com

Ret-3570lp user manual, Software interface – RoyalTek RET-3570LP User Manual

Page 16

background image


RoyalTek Confidential

14

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