ABB ACS320 series, User Manual

Page: 286 / 442

286 Fieldbus control
Mechanical and electrical installation – EFB
WARNING! Connections should be made only while the drive is disconnected
from the power source.
Drive terminals 23…26 are for EIA-485 communications.
• Use Belden 9842 or equivalent. Belden 9842 is a dual twisted, shielded pair cable
with a wave impedance of 120
Ω
.
• Use one of these twisted shielded pairs for the EIA-485 link. Use this pair to
connect all A (-) terminals together and all B (+) terminals together.
• Use one of the wires in the other pair for the logical ground (terminal 26), leaving
one wire unused.
• Do not directly ground the EIA-485 network at any point. Ground all devices on
the network using their corresponding grounding terminals.
• As always, the grounding wires should not form any closed loops, and all the
devices should be grounded to a common ground.
• Connect the EIA-485 link in a daisy-chained bus, without dropout lines.
• To reduce noise on the network, terminate the EIA-485 network using 120
Ω
resistors at both ends of the network. Use jumper J701 to connect or disconnect
the termination resistors. See below wiring diagram. This circuit provides pull-up
active termination resistors.
• For configuration information see the following:
- below.
- Activate drive control functions – EFB on page 292 .
- The appropriate EFB protocol specific technical data. For example, Modbus
protocol technical data on page 336 .