M7 GX Technical Manual
66
Raveon Technologies Corp.
waypoint ID field, the
RV-M7 GX
puts the ID of the RV-M7 that transmitted its
position.
For example, if a
RV-M7 GX
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
RV-M7 GX
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 display 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
RV-M7 GX
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
m
essage. For example, if the prefix is set to the phrase “Car”, the
RV-M7 GX
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.
15.4.
$PRAVE Raveon Proprietary Message, Location-Status
The $PRAVE message is sent out the
RV-M7 GX
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.
Along with ID and position information, it contains a host of other status
information. The length of this message may exceed he standard NMEA limit of 79
characters. Any product or software that uses this message must take this into
account.
Following is a list of the fields sent in this message
Field
Usage
Comments
1
$PRAVE
Raveon Proprietary Header
2
From ID
The ID of the transponder that transmitted its position over the air. It
is a decimal number, 0 – 9999.
3
To ID
The ID that this position report was sent to. It is a decimal number, 0
– 9999.
