5 Installation
5.3 Interfaces
50
HMI/PLC XV-102
08/2016 MN04802004Z-EN
www.eaton.com
Wiring
Screened twisted-pair cables must be used.
Tab. 24 Cable specifications
RS485-topology
A bus segment can interconnect up to 32 slaves.
Several bus segments can be connected using repeaters (bi-directional amplifiers). Refer to the
documentation of the repeater manufacturer for more specific details.
A bus segment must be provided with cable termination (120
) at both ends. These terminals
must be connected in the connector directly between pin 3 and 7.
Cable specifications
Rated surge impedance
120
Permissible surge impedance
108…132
Max. cable length
1200 m
Possible baud rates
9600 Bit/s
19200 Bit/s
38400 Bit/s
57600 Bit/s
115200 bit/s
When preparing the cables, ensure that there is a low-resistance connection between
the cable screen and the connector casing (
The use of repeaters enables the maximum cable length to be increased. Refer to the
documentation of the repeater manufacturer for more specific details.
The bus segment must be terminated at both ends.
No more than two terminations must be provided for each bus segment.
Operation without correct cable termination can cause transfer errors.
Fig.. 26 Bus segment with four nodes
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
