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5 External connections
5.4 Serial interfaces to other devices
54
Compact PLC XC-152
05/17 MN050001ZU EN www.eaton.com
CAN relationship between cable length / baud rate
5.4.3.2 CAN-Bus-topology
•
A bus segment can interconnect up to 32 slaves.
•
Multiple bus segments can be connected with the use of repeaters
(bi-directional amplifiers).
A bus segment must be provided with a cable termination (120
) at both
ends.
These terminations must be connected inside the plug, directly between
PINs 3 and 7.
Figure 19:
CAN bus segment with four nodes
Cable length
Possible baud rate
25 m
1000 kbit/s
50 m
800 kbit/s
100 m
500 kbit/s
250 m
250 kbit/s
500 m
125 kbit/s
500 m
100 Kbit/s (adjustable via software)
1000 m
50 kbit/s
2500 m
20 kbit/s
5000 m
10 kbit/s
→
The use of repeaters enables the maximum cable length to be
increased.
Repeaters can also be used for galvanic isolation. For more
details, please consult the documentation for repeaters pro-
vided by manufacturer.
Make sure to follow the recommendations provided by CiA
(CAN in Automation) at http://www.can-cia.org.
→
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 transmis-
sion errors.