User's Manual

Atlas PT Technical Manual
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Serial Sleep Mode
Using the ATCM 1 command, the ATLAS PT can be set to disable the RS-232 port until
a character is received. Combined with other power saving modes, this can result in
many additional hours of operations if the serial power is not needed.
In Serial Sleep Mode, the RS-232 will not output any data and will remain in a low
power mode until any character is received. One a single character is received, the
serial port will wake up permanently until the unit is power cycled.
6.4 Data Transmission
To transmit data, send one or more bytes of data into the serial port of the modem.
When a full packet of data has been collected into the internal buffer of the modem, or
when there is a pause in the data, the modem will automatically key its transmitter, and
send the data over the air when the unit’s TDMA time slot is available.
The ATLAS PT will send position/status as well as transmit and receive serial data.
For advanced, tighter integrations, all communication to the radio may be performed
using the Wireless Modem Exchange (WMX) protocol. Refer to the protocol
specification for more information. The ATLAS PT is fully WMX enabled.
6.5 Data Reception
Serial Port Data
When the ATLAS PT receives RS232 data over the air, 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 over-the-air baud rate.
GPS Position and Status
When the ATLAS PT receives a position report and status from another Atlas SM, it will
send this information out its RS232 port, formatted as configured with the GPS x
command. The ATLAS PT is GPS mode 8 (GPS 8). The default output message
format is Raveon’s $PRAVE message.
Change the position report output format with the OUTPUT x command. Enable/disable
the local GPS NMEA data with the NMEAOUT x command (0 off, 1 on)
The position/status messages that the ATLAS PT is able to send out of its serial port
are:
Message
Format
Description
OUTPUT x
Parameter/setting
$GPWPL
NMEA WayPoint List. This message is
commonly used to share waypoint locations
among GPS units. The ATLAS PT can output
this message when it receives a position report
from other ATLAS PT transponders. A GPS
OUTPUT 3