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2. Hardware Implementation of the LUFP9 Gateway
2.5. Connecting the Gateway to the Modbus Network
Three typical examples of Modbus connection for the gateway and its slaves are shown below. There are many
other possible Modbus connections, but they are not covered in this document.
2.5.1. Examples of Modbus connection topologies
• “Star” topology: This topology uses LU9GC03 Modbus hubs, which have 8 female RJ45 connectors.
These hubs should be placed close to the Modbus slaves to which they are connected using
VW3 A8 306 R•• cables. On the other hand, the nature of the cable connecting the LUFP9 gateway to one
of these hubs will depend on the network architecture, so long as there is a male RJ45 connector at each
end. If necessary, one or two line terminations may be directly connected to the hubs.
The connections are shown below:
Modbus
VW3 A8 306 R••
Modbus
LUFP9 gateway
Line
termination
Towards 8 Modbus slaves
Modbus hubs
LU9GC03
Line
termination