Modbus MFU Option Card Installation Manual
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Publication PUB091-003-00_0119
1.1 General
The Modbus Module has three variants:
Single RS-485 highway plus one analogue input channel
Dual Independent isolated RS-485 highways
Single RS-485 highway with inbuilt isolating repeater
Communication Medium
RS4-85 2-wire highway (single or dual), half duplex
Protocol
Modbus RTU
Mode
Master/Slave, module is a slave
Fig 2: The Types of Modbus Module Mk2 Option Card
RS485
Highway
Analogue
Input
Single H Analogue Input
Dual Highway
Single H Repeater
RS485
Highway 1
RS485
Highway 2
RS485
Highway 1
RS485
Highway 1