Westermo RM-455U-D User Manual
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Chapter Three
Configuration
Man_455U-D Rev 3.04
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In the configuration below you will see that Modbus Slave address #1 is attached to remote
radio #22 and the message needs to be sent via a repeater radio (#21), same with Modbus
Slave Address #2 except it is attached to the remote radio #23.
Modbus address #3 is attached to Remote radio #24 and communicates through two repeaters
(#21 & #23).
The next three Modbus Slaves are all connected to the same remote radio (#25) and each link
needs a separate configuration.
Finally if you are setting up a large system and the remote radios have consecutive Protocol
devices you can use the “First” and “Last” address range which will configure a number of
remote devices each with an attached Protocol address.
3.10.2 Configuring for Modbus Protocol (RTU or ASCII)
With Modbus protocol, the master station does not have an address. This means that for each
remote, you need to configure a path back to the master station which uses the remote’s own
address as the Protocol address.
At the master station, you must configure a path to each remote station, using the address of
the remote station as the protocol address.