CSI Wireless ABX-3, Reference Manual

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ABX-3 / MBX-3 Reference Manual 57
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5.3 NMEA Message Elements
All NMEA 0183 messages possess a common structure, including a
message header, data fields, and a terminating carriage return and line
feed.
Example: $GPYYY,xxx,xxx,xxx…<CR><LF>
Table 5-1 displays the elements of this example message.
Table 5-1 NMEA Message Elements
Element Description
$GP Message Identifier Indicating a GPS Related Message
YYY Type of GPS Message
Xxx Variable Length Message Fields
<CR> Carriage Return
<LF> Line Feed
Null fields occur when no information is available for a field.
To issue NMEA commands, use a program with a terminal utility
running on a PC computer. You may type these commands into the
terminal window once you have matched the communication
parameters between the terminal program and the receiver. You must
ensure that when you press the Enter key on your PC to send a
command, it represents both a carriage return <CR> and line feed
<LF>. If a NMEA command is not working, this terminal facility option
may not be set correctly. Please contact your dealer, or CSI Wireless
Customer Service for more information.
5.3.1 CSI Wireless DGPS Command Center
If you are using CSI Wireless's DGPS Command Center program, the
terminal window allows you to issue NMEA commands or queries to