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Raveon Technologies Corp.
other Transponders. The GPS will normally output various NMEA messages
from its serial port. These NMEA messages from the external GPS must not be
transmitted, or the radio channel will become much too busy. The
M6G
“mutes”
its data input when configured in GPS mode 4.
The
M6G
will send position/status as well as transmit and receive serial data
when it is in GPS mode 2.
Serial Port Baud Rate
While the modem is transmitting, the user may continue to send more data into
the
M6G.
Because the buffers in the M6G are full-duplex, the serial port data rate
and the over-the-air data rates are independent. The serial port baud-rates may
be set slow to accommodate legacy equipment, or set at high-speed to minimize
latency. The over-the-air data rate us usually 4800 baud for narrow-band
channels, and 9600 baud for wide-band, although faster or slower rates may be
used.
8.6.
Data Reception
Serial Port Data
When the
M6G
receives RS-232 data over the radio, it checks it for errors, and if
it is error-free, it will send it out the serial port. Again, the serial port may be set
to any baud rate the user wishes, and the radio receiver and transmitter will
continue to operate independently of the baud rate.
When the modem receives a radio signal, it will assert the CD hardware signal on
the RS-232 serial port if it was configured to do so.
GPS Position and Status
When the
M6G
receives a position report and status from another
M6G
, it will
send this information out its RS-232 port, formatted as configured with the
OUTPUT x
command. See Section
Error! Reference source not found.
for
detailed information on the type and format of message output from the
M6G
when a position/status report is received from some other unit. Note, the
GPS x
command is a macro that sets many parameters, one of which is the
OUTPUT
.
When the GPS x command is executed, it will set the OUTPUT setting to the
appropriate message format for the particular GPS mode. After the
GPS x
command is executed, you may then issue the
OUTPUT x
command to modify
the output protocol.
The position/status messages that the
M6G
is able to send out of its serial port
are:
None
No position message output.
Output 0
disable the device from outputting
any message when a position report is received.
$PRAVE
Raveon Position & Satus.
Output 1
This message is sent out of the
M6G
when it is operating in the
GPS 2
mode. This message is used by third-party
and PC applications for tracking location and status information.
