Chapter 2 Decentral block periphery CAN-Bus CANopen
Manual VIPA System 100V
2-8
HB100E - SM-CAN - Rev. 15/02
Via the address selector, you select the CAN baudrate as well as the
module-ID.
More detailed information is to find under "Baudrate and module-ID
settings" in this chapter.
The CAN-Bus coupler has an integrated mains power supply. It has to be
provided with DC 24V.
The mains power supply is protected against inverse polarity and over-
current.
CAN is a 2wire bus system where all participants are connected in parallel.
The bus has to be terminated at both ends with a terminating resistor of
120 (res. 121)
Ω
to avoid reflections. This is also necessary for short cable
lines.
node 1
120
Ω
CAN Bus
CAN_H
CAN_L
120
Ω
node n
. . . . . . . . .
For all CAN signals are monitored at the bus as difference levels, the CAN
line is comparable less sensitive to interference (EMC). Due to the fact that
always both lines have the same environment, the interference doesn't
affect the difference level.
Note!
The bus cable has always to be terminated with a terminating resistor of
120
Ω
to avoid reflections and therefore transfer problems!
For the CAN cabling, you use a screened twisted-pair cable (2x2) with a
ripple resistor of 108...132
Ω
.
When the bus potential of the CAN receivers (CAN ground) is not
connected, you can leave the second pair of cores. This is only convenient
with small net extensions and common supply of all participants.
Address selector
for baudrate and
module-ID
Power supply
Cabling under
CAN-Bus
Cable