Company Confidential
38
Raveon Technologies Corp.
$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-M29
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-M29 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-M29
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-M29, 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
RV-M29
will
output the following message when it receives a position report from RV-M29
Transponder with ID 0003.
$GPWPL,4917.16,N,12310.64,W,Car3*65
And on a GPS display connected to the RV-M29, 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.
10.6.
$PRAVE Raveon Proprietary Message, Location-Status
The $PRAVE message is sent out the
RV-M29
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.
4
Latitude
dddmm.mmmm format. It is signed. + is north, - is south. No sign
means north. Note: typically there are 4 decimal places, but as few
as 0 decimal places are possible. Null field if no GPS lock.
5
Longitude
dddmm.mmmm format. It is signed. + is east, - is west. No sign
