ABB AC500 PLC Hardware Manual page 1144

Device Specifications
Accessories > AC500-eCo
Master at the bus line end, pull-up and pull-down activated, bus termination with 120 W
1
resistors
2 Direct grounding via clip or steel plate
1.8.1.10.4 Technical Data
Parameter
Physical link
Electrical Isolation
Usage / Supported protocols
Supported baudrates [baud]
Connector at the communication line
Connector at PM554 or PM564
Cable type and specification
Max. cable length for Modbus
1144
120 Ω
CS31
Slave
NOTICE!
Risk of EMC disturbances!
Unshielded cables may cause EMC disturbances.
Always use shielded cables and connect the shield at every device.
Modbus
CS31 system bus
Recommended cable cross section
Thinnest cable cross section
at 38.4 kBaud or below
at 187.5 kBaud
3ADR010121, 13, en_US
2
1
2
3
4
CS31
5
Slave
1
Value
RS-485
Yes
Modbus (Master and Slave)
CS31 (Master only)
9.6 k, 14.4 k, 19.2 k, 38.4 k and 187.5 k
187.5 k
5-pin screw terminal block
D-sub 9, male
Twisting rate minimum 10 per meter, with
common shield
Capacitance between the cores: < 55 nF/km
Characteristic impedance: 120 W
Conductor cross section 0.5 mm²
Resistance per core: < 40 W/km
Conductor cross section 0.22 mm²
Resistance per core: < 100 W/km
1200 m with cable cross section 0.5 mm² or
400 m with cable cross section 0.22 mm²
500 m with cable cross section 0.5 mm² or 400
m with cable cross section 0.22 mm²
120 Ω
2019/04/17