Verifying Communications with RavTrack PC

RavTrack PC receives $PRAVE messages from a Raveon GPS tracking transponder, and uses the information in the $PRAVE message to plot the position and display the status of tracked vehicles and personnel.

The $PRAVE messages come out of the M7 GX transponder, when it is configured in GPS mode 2.  The serial port of the M7 GX transponder must be connected to the PC running RavTrack PC.   This connection may be a direct RS232 connection, or it may use a terminal server to convert the RS232 from the M7 GX transponder to Ethernet. The Ethernet connection is then made to a LAN or WAN so that RavTrack PC can receive the GPS positions via the nework connection.

To verify that RavTrack PC is receiving $PRAVE messages, you can look at the communications statistics window within RavTrack PC, and see if $PRAVE messages are comming out.


In the “Messages In” column, there are two numbers (xxx/yyy)  The first number xxx is the total number of messages, and the second number, yyy, is the total number of $PRAVE messages that RavTrack PC has received.

If the communications with the M7 GX transponder is OK, the second number will increment each time a $PRAVE message is received, which is each time a transponder reports in. In the above example, RavTrack PC has received 311 position reports using its network connection.

If the second number is 0, but the first number is not zero (ie  123/0)  then the connection to the M7 GX is probably OK, because some messages are coming in.  These are usually the $GPGGA/RMC type messages output from the local GPS in the M7.  They are not over-the-air position reports.  Because the first number is incrementing, the connection to the M7 is OK. But, because the second number is 0, there are not $PRAVE messages coming in.  The most likely reasons that there are not $PRAVE messages are:

1.  All transponders are turned off.

2.  The UHF or VHF antenna to the M7 GX used with RavTrack PC is not connected.

3. The encryption keyphrase is not set corectly, and the My GX cannot receive the position reports.

4. All transponders are out of range of the M7 GX used with RavTrack PC.

5. The transponders are configured on a different RF frequency.

Hopefully you find this information helpfull.  Monitoring the communication statistics is an excellent way to verify the performance of your RavTrack GPS tracking system.  RavTrac PC automatically monitors the statistics, and will turn the communication status button on the bottom of the screen red if no messages are received for a long period of time, indicating that the communications with the transponder used to receive $PRAVE messages has failed.