User Guide

SECTION 4

SOFTWARE INTERFACE

This section describes the details of the serial port

commands through which the HI-204

III

-USB

is controlled

and monitored. The serial port commands allow users to set

the receiver parameters, configure output message type,

and retrieve status information. The baud rate and protocol

of the host COM port must match the baud rate and

protocol of the GPS receiver serial port for commands and

data to be successfully transmitted and received. The

default receiver protocol is 4800 bps, 8 data bits, 1 stop bit,

and none parity.

4.1 NMEA OUTPUT MESSAGE SPECIFICATION

The HI-204

III

-USB

supports NMEA-0183 output format as

defined by the National Marine Electronics Association

(http://www.nmea.org). The currently supported NMEA

messages for GPS applications are:

GGA

GLL

GSA

GSV

RMC

VTG

Global Positioning System Fix Data

Geographic Position Latitude / Longitude

GNSS DOP and Active Satellites

GNSS Satellites in View

Recommended Minimum Specific GNSS Data

Course Over Ground and Ground Speed