ABB AC500 PLC Hardware Manual page 1143

Slave at the bus line end, bus termination with 120 W resistors
1
2 Master within the bus line, pull-up and pull-down activated
3 Slave within the bus line
Slave at the bus line end, bus termination with 120 W resistors
4
The cable shields must be grounded
Connection: The following figure shows an CS31 bus with the bus master at the line end.
CS31 Protocol
Master at the bus line end, pull-up and pull-down activated, bus termination with 120 W
1
resistors
2 Direct grounding clip or steel plate
If the master is located within the bus line, it does not need a terminating resistor. The pull-up
and the pull-down resistors, however, are necessary:
2019/04/17
NOTICE!
Risk of EMC disturbances!
Unshielded cables may cause EMC disturbances.
Always use shielded cables and connect the shield at every device.
NOTICE!
Risk of malfunctions!
The pull-up resistors must be used only one time within a bus line.
Use the pull-up resistors only at 1 master.
1
2
120 Ω
3
4
5
1
3ADR010121, 13, en_US
Ä Chapter 2.5.4.4 "CS31 bus" on page 1214.
CS31
Slave
Device Specifications
Accessories > AC500-eCo
2
CS31
Slave
120 Ω
1143