Inovance MD500T110G-INT - Page 244

8. Peripherals and Options
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It is recommended to use an STP cable as the RS485 bus and use a twisted cable to
connect 485+ and 485-. Connect a matching terminal resistor of 120 Ω respectively at
both ends of the bus to prevent signal reection. The RS485 bus allows connection of
a maximum of 128 nodes and the distance of each node branch must be smaller than
3 m. Connect the reference ground of all nodes together.
The connecting modes of multiple nodes are described as below:
Daisy chain connection mode
Master Slave 1
Slave 2 Slave 3 Slave N
RS485 bus
. . .
Recommended
Branching connection mode
Master Slave 1 Slave 2 Slave 3 Slave N
RS485 bus
3 m
3 m
3 m
. . .
Recommended
Note
Distance from the bus to the node cannot exceed 3 m.
Star connection mode (prohibited)
Master
Slave 1
Slave 3 Slave 6
Slave 4
Slave 5
Slave 2
Prohibited