User Manual

A NMEA-0183 Output
182 5700/5800 GPS Receiver User Guide
5700 & 5800 Reference
A.1 Introduction
This appendix describes the formats of the subset of NMEA-0183
messages that are available for output by the receivers. For a copy of
the NMEA-0183 Standard, visit the National Marine Electronics
Association website at www.nmea.org.
A.2 NMEA-0183 Outputs
When NMEA-0183 output is enabled, a subset of NMEA-0183
messages can be output to external instruments and equipment
connected to the 5700 serial ports. These NMEA-0183 messages let
external devices use selected data collected or computed by the 5700
receiver.
All messages conform to the NMEA-0183 Version 2.30 format. All
begin with $ and end with a carriage return and a line feed. Data fields
follow comma (,) delimiters and are variable in length. Null fields still
follow comma (,) delimiters but contain no information.
An asterisk (
*) delimiter and checksum value follow the last field of
data contained in an NMEA-0183 message. The checksum is the 8-bit
exclusive OR of all characters in the message, including the commas
between fields, but not including the $ and asterisk delimiters. The
hexadecimal result is converted to two ASCII characters (0–9, A–F).
The most significant character appears first.
Table A.1 summarizes the set of NMEA messages supported by the
5700 receiver, and shows the page where detailed information about
each message can be found.
Table A.1 NMEA message summary
Message Function Page
GGA Time, position, and fix related data 185
GST Position error statistics 186
GSV Number of SVs in view, PRN, elevation,
azimuth, and SNR
187