Eaton XV300 - RS-485 Topology

5. External connections
5.5 Serial interfaces for communication with PLCs or devices
5.5.2.2 RS-485 topology
l A bus segment can interconnect up to 32 slaves.
l Several bus segments can be connected using repeaters (bi-directional amplifiers).
The use of repeaters enables the maximum cable length to be
increased.
For more details, please consult the documentation provided by man-
ufacturer.
A bus segment must be provided with cable termination (120 Ohm) at both ends.
These terminals must be connected in the plug directly between pin 3 and 7.
The bus segment must be terminated at both ends.
No more than two terminations must be provided for each bus seg-
ment.
Operation without correct cable termination can cause transfer
errors.

1
2
3
6
7
5
4
8
9
120
1
2
3
6
7
5
4
8
9
120
1
2
3
6
7
5
4
8
9
1
2
3
6
7
5
4
8
9
GND
A
B
GND
A
B
GND
A
B
GND
A
B
GND
A
B
GND
A
B
Figure 33: Bus segment with four nodes
XV30004/19 MN048017ENwww.eaton.eu
63