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Chapter 4: Network Topologies
Master
• Enter into Command Mode.
• Change S141 (Repeaters Y/N) to 1 (which means “Yes”).
• Save the change using the AT&W command.
• Go online with the ATA command.
Repeater
• Enter into Command Mode.
• Load a third modem with &F7 (PTP Slave factory default settings).
• Change the Operating Mode (S101) from 2 (Slave) to 1 (Repeater).
• Change the Unit Address (UA) (S105) from 2 to 3.
• Save the changes using the AT&W command.
• Go online with the ATA command.
Slave
• Enter into Command Mode.
• Change S118 from 1 (the UA of the Master) to 3 (the UA of the Repeater).
• Save the change using the AT&W command.
• Go online with the ATA command.
You can test this system by sending text at 9600 bps, 8N1 through the RS-232 serial port of one modem and observing that it
appears at the RS-232 serial port of the other modem. The Slave is synchronized to the Repeater, which in turn is synchronized to
the Master. If the Repeater is taken offline, in a matter of moments the Slave’s RSSI LEDs will indicate that it is “scanning” for its
immediate upstream unit; place the Repeater online and the Slave will quickly acquire it. If the Master is taken offline, both the
Repeater and Slave will begin to scan.
4.2 Point-to-Multipoint (PMP)
In a point-to-multipoint network, a path is created to transfer data between the Master modem and numerous remote modems.
The remote modems may simply be Slaves with which the Master communicates directly, and/or Slaves that communicate via
Repeaters. Some or all of the Repeaters may also act as Slaves in this type of Network, i.e., the Repeaters are not only storing and
forwarding data, but are also acting as Slaves. Such Repeaters may be referred to as “Repeater/Slaves.”
Factory default settings:
Master
&F1
Slave
&F2
Repeater
&F3
slow mode (optional):
Master
&F4
Slave
&F5
