Wiring Notes
CAN-CBM-Clock
Hardware Manual • Doc.-No.: C.2836.21 / Rev. 1.3
Page 25 of 34
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6.2 Light Industrial Environment (Single Twisted Pair Cable)
6.2.1 General Rules
The following general rules for CAN wiring with single shielded single twisted pair cable should be
followed:
1
A cable type with a wave impedance of about 120
±10% with an adequate conductor cross-
section (
0.22 mm²) has to be used. The voltage drop over the wire has to be considered!
2
For light industrial environment use at least a two-wire CAN cable.
Connect
the two twisted wires to the data signals (CAN_H, CAN_L) and
the cable shield to the reference potential (CAN_GND).
3
The reference potential CAN_GND has to be connected to the functional earth (FE) at
exactly one point.
4
A CAN net must not branch (exception: short cable stubs) and has to be terminated with the
characteristic impedance of the line (generally 120
±10%) at both ends (between the signals
CAN_L and CAN_H and not at CAN_GND)!
5
Keep cable stubs as short as possible (l < 0.3 m)!
6
Select a working combination of bit rate and cable length.
7
Keep away cables from disturbing sources. If this cannot be avoided, double shielded wires are
recommended.
Figure. 6: CAN wiring for light industrial environment