ABB ACS380 Hardware Manual page 70

70 Electrical installation
Connecting the fieldbus to the drive
Connect the fieldbus to the EIA-485 Modbus RTU terminal on the BMIO-01 module
which is attached on the control unit of the drive. The EIA-485 network uses shielded,
twisted-pair cable for data signaling with characteristic impedance between 100 and
130 ohm. the distributed capacitance between conductors is less than 100 pF per
meter (30 pF per foot). Distributed capacitance between conductors and shield is less
than 200 pF per meter (60 pF per foot). foil or braided shields are acceptable. The
connection diagram is shown below.
Termination OFF
Drive
1) The device at both ends on the fieldbus must have termination set to ON.
Data flow
Control Word (CW)
References
Status Word (SW)
Actual values
Parameter R/W
requests/responses
ON ON
ON
1
1 1
Termination OFF
Drive
Fieldbus controller
(1
Termination ON
Fieldbus
Process I/O (cyclic)
Service messages (acyclic)
ON ON
ON
...
1
1 1
Termination ON
Drive
ON ON
ON
1
1 1
(1