M7 GX Technical Manual
41
Raveon Technologies Corp.
KEYPHRASE Jkl53hhp <enter>
ID Addressing Basics
ID addressing is used to differentiate one RV-M7 Transponder from another. Each
must have a unique number programmed into them, so that when a position report
is received, the
RV-M7 GX
that sent the message can be identified. This is called
the MYID of the unit that sent the message.
Each
RV-M7 GX
has a MYID programmed into it, and is represented as a 4 digit
decimal number.
RV-M7 GX
IDs may be any number between 0001 and 9999.
The Unit Address is programmed with the
MYID xxxx
command, and the ID of the
destination modem it sends its messages to (the Destination Address) is
configured with the
ATDT xxxx
command.
The factory default
MYID
in all
RV-M7 GX
modem is 0001, and 0001 is also the
default for the Destination ID also. The ID of your particular
RV-M7 GX
may have
been configured by your dealer or distributor. If so, it is labeled on the rear of the
unit. If it is not labeled with an ID, the factory default ID is in it.
The default Address Mask is F000, which means the
RV-M7 GX
will receive a
transmission from any other RV-M7 as long as the fist digit matches, in this case, is
a 0.
Make sure you set the
MYID
of each
RV-M7 GX
in your system to a different
number.
For example, to set the ID of your
RV-M7
GX
to 17, enter:
MYID 17 <enter>
To set your RV-M7 to send its position and status data to RV-M7 number 1, enter:
ATDT 1 <enter>
To set your address mask to receive all messages from units with IDs 1-999, and
exclude 1000-9999, enter
ATMK F000 <enter>
Time Slots
The
RV-M7 GX
uses a transmission scheme popular in mobile-telephones called
TDMA (Time Division Multiple Access). Each
RV-M7 GX
is allocated a time-slot to
use for sending and receiving radio messages.
Refer to Section 10.3 for detailed explanation of the TDMA scheme. The important
point to understand is that for optimum efficiency in a
RV-M7 GX
system, begin
sequentially numbering the MYID of the
RV-M7 GX
transponders at ID 0001. The
second RV-M7 should be ID 0002, and so on.
The
RV-M7 GX
transponders have internal clocks with 20 ticks-per-second. They
can measure time and initiate transmissions 20 times every second (every 50mS).
The TDMA time slot is configured to be some number of these ticks. The factory
default allocation is 4-ticks for one time-slot. So each TDMA time slot is 200mS
long, and thus in 10 seconds, up to 50
RV-M7 GX
transponders may report
