User's Manual

Company Confidential 60 Raveon Technologies Corp.
transmission. Once the modem has sent its data the number of times the user
s
pecified in the ATRB xx command, the data is discarded, and the modem will
continue to operate as normal.
It is very important that if one modem is configured to send ACK packets (ATAK
1) that all other modems communicating with it are also set to expect ACK
packets using the ATRB xx command.
To disable ARQ (the default condition of the modem), disable ARQ with the
ATAK 0 and
set retries to zero with the ATRB 0 command.
6.7. Store-and-Forward Repeating
The M7 modem has a built-in wireless repeater. Each M7 is capable of not only
sending and receiving data from/to its serial port, but also re-transmitting data
packets it receives over-the-air data.
To use the Store-and-Forward repeater feature, the modem must be used in the
“Packet Mode”. This is the factory default operation mode. In the Packet Mode,
data is sent over-the-air in bursts called packets, and each packet has the Unit ID
of the SkyLine that sent the data and the destination ID of the unit that the data is
intended for.
Figure 3 Overview of Repeater Operation
In the example shown in Figure 3 above, M7 A is will communicate with all other
modems in the system. It can directly communicate with B, H, and F. Because
of propagation limits, it cannot communicate reliable to
E, D, C, and G.
To
solve this problem, some of the M7 modems are configured as repeaters.
The still are able to send and receive data, but they also will repeat data out to
the modems that are out of range of M7 A.