Westermo RM-455U-D User Manual

Page 37

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455U-D Radio Modem

User Manual

Page 38 © May 2010

3.5.4 Broadcast Network

You may want a multi-hop network to broadcast messages. This takes some care at the
repeater nodes to ensure that individual repeaters do not repeat messages that they have
already repeated, and also to avoid an “end-node” receiving the same message multiple times.

Note - Before deciding to implement a multi-hop broadcast network, check the section below
on Optimum Path Routing. If your communication uses Modbus, DF1, or DNP3 protocols,
OPR may be a better way to implement your network.

You can set up a broadcast network by
using address strings of the form
<0,0,0> etc. That is, the destination
address is the wildcard 0 and the
repeater addresses are the wildcard 0.

Consider the following network:

This network has a maximum of three “hops” - to reach the most remote units, there needs to
be three transmissions or hops. Unit 1 needs to transmit with address <0,0,0> - that is, three
hops.

#1

#14

#15

#21

#22

#36

#37

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