User Manual

Communication
Modbus RTU over RS485
6
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6 Communication
6.1 Modbus RTU over RS485
Features
The Climatix controller RS485 interface supports the Modbus RTU communications
protocol to connect Modbus devices (examples):
● Control drives via variable speed drives (master mode)
● Exchange of information with a monitoring system (slave mode)
Terminal assignment
The following illustration shows the identification of the terminals of Climatix
controllers.
Connection example
Note: Connect REF to the reference signal ground on the RS485 network. Do not
connect REF to the shield on the twisted pair cable.
Supported Modbus function code
The following common Modbus function codes are supported by Climatix controller
for Modbus communications.