ABB ACH550-BCR, Руководство пользователя

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ACH550 E-Clipse Bypass User’s Manual 2-83
Embedded fieldbus
Mechanical and electrical installation – EFB
Warning!
Connections should be made only while the bypass is disconnected from
the power source.
Bypass terminals 26…30 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 both of the other wires in the other pair for the reference/common
(terminal 29).
• Do not directly ground the EIA 485 network at any point. Ground all devices on
the network using their corresponding earthing terminals.
• As always, the grounding wires should not form any closed loops, and all the
devices should be earthed to a common ground.
• Connect the EIA 485 link in a daisy-chained bus, without dropout lines.
• Do not connect the shield at the bypass. Tie the shields together at the bypass.
Only load the shield connection at the EIA 485 master.
• For configuration information see the following:
–
Communication setup – EFB
section.
–
Activate drive control functions – EFB
section.
– The appropriate EFB protocol specific technical data.
– To reduce noise on the network, terminate the EIA 485 network using 120
Ω
resistors at both ends of the network. Use the DIP switch to connect or
disconnect the termination resistors. See following diagram and table (on next
page).