Atlas PT Technical Manual
40
3
Lon
Longitude of the position
4
E/W
East or west. One character.
5
WP Name
The ID of the unit that transmitted its position plus
any user-set prefix.
cks
NMEA checksum
When the ATLAS PT
is set to
GPS 4
mode of operation, it will output this message
every time it receives a position report from another ATLAS PT
transponder. Within the
WPL message, is the latitude, longitude, and “waypoint ID”. In the waypoint ID field, the
ATLAS PT
puts the ID of the RV-M7 that transmitted its position.
For example, if an ATLAS PT
receives a position report from ID 0003 located at
4917.16N, 12310.64W it sends out the following message.
$GPWPL,4917.16,N,12310.64,W,3*65
The lat/lon is sent using the dddmm.mm format, where ddd is the degrees, and
mm.mmmm is the decimal minutes. There is no sign to these numbers.
GPS 4 mode with the $GPWPL message is the most common way of using the ATLAS
PT
with a hand-held or mobile GPS. Most any GPS with a serial-data input will accept
the $GPWPL message, and put an icon on its screen, with a label showing the ID of the
RV-M7 at that position.
Some GPS displays have an issue when a new position report is received. Most will
move the waypoint to the new location, but some re-draw a new waypoint at the new
position, and leave the old waypoint in place.
To help make the waypoints easier to read, the ATLAS PT
may be programmed with an
ID prefix, using the
PREFIX vvvv
command. The default is a capitol letter V. Set it to a
dash (-) to disable the prefix string. If a prefix is programmed into the RV-M7, it will add
the prefix characters whenever it outputs the ID in a $GPWPL message. For example,
if the prefix is set to the phrase “Car”, the ATLAS PT
will output the following message
when it receives a position report from RV-M7 Transponder with ID 0003.
$GPWPL,4917.16,N,12310.64,W,Car3*65
And on a GPS display connected to the RV-M7, the waypoint will show up at the correct
lat/lon
with the waypoint name “Car3”. In most all GPS receivers, this waypoint will also
be added to its internal database of waypoints.
11.3
$PRAVE Raveon Proprietary Message, Location-Status
The $PRAVE message is sent out the ATLAS PT
when it is configured for
GPS 2
mode
of operation. This mode is typically used with the RavTrack PC program, or other
computer programs that can process position and status information. It is sent at 38.4K
bytes/second out the serial port.
