ABB Advant AC500 - Page 37

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V2 AC500 Hardware 1-37 System data AC500 / Issued: 05.2007
CS31 system bus
CS31
Shield
BUS 2 BUS 1
Shield
BUS 2 BUS 1
slave
CS31
slave
120
Ohms
120
Ohms
direct
earthing
with clip
1
2
3
4
COM1
Master within
the bus line,
pull-up and
pull-down
activated
CS31 bus master
e.g. PM581
Figure: Bus topology for a CS31 system bus at COM1 (bus master within the bus line)
CS31 system bus
CS31
Shield BUS 2 BUS 1
slave
CS31
CS31
Shield BUS 2 BUS 1
slave
1
2
3
4
120
Ohms
COM1
CS31 bus master
e.g. PM581
Master at the
bus line end,
pull-up and
pull-down
activated
bus termination
120 Ohms
system bus
WRONG!
Spur lines are not
allowed.
RIGHT!
Bus line is looped through
from module to module.
Figure: Wiring with spur lines is not allowed