If you want LT 1 to beacon with a path of GPS via a digipeater (called DIGI) and
you want the beacon to occur every 30 minutes, use the following commands:
LTP 1 GPS via DIGI
BLT 1 EVERY 00:30:00
+
Several amateur groups, such as APRS (see the bibliography at the end of the
GPS section), have developed special programs for enhancing amateur GPS ac
-
tivities. Check with them for current practice in setting GPS beacon paths, bea
-
con rates, and frequencies used in your area.
You can also set up a “tracking buffer” to store the most recently transmitted LT
information for later retrieval. The size of the buffer and which LT buffers to
store, is controlled by the LTRACK command. For instance, the command
LTRACK 5 LT1 LT2
would set the size of the LTRACK buffer to approximately 5 Kbytes and store
the LT 1 and LT 2 buffers whenever they are transmitted (as set by the BLT com-
mand).
GPS Unit Initialization from the TNC
Some GPS receivers require reception of a special string of characters for initial-
ization before they will send any information. You can tell your TNC to send the
initialization string to your GPS unit by entering the required string using the
GPSINIT command. For instance, if your GPS receiver requires the string
$PGRMO,GPGGA,1 to be sent, you would give the command
GPSINIT $PGRMO,GPGGA,1
to your TNC. Upon power up, the TNC will then send that string via its serial
port to the GPS unit (when the TNC INTFACE command is set to GPS.)
GPS Operations
Starting the TNC in GPS Mode
+
Hint: Be sure to set ABAUD rate to that required by your GPS unit.
Once you have the TNC parameters set for GPS, you need to set the TNC to start
in GPS Mode on power up. To do this, set the INTFACE command to GPS.
Packet Modes of Operation GPS NMEA Interfacing Capability
User’s Guide 184 KAM’98 v 8.3
To Next Page
Loading...