ABB ACS380 Series, Hardware Manual

Page: 159 / 186

BTAC-02 pulse encoder interface module 159
Phasing
When the encoder is connected correctly, running the drive in the Forward (positive
speed reference) direction should produce a positive encoder speed feedback.
Option A: Oscilloscope test . On incremental encoders, the two output channels,
typically A and B or 1 and 2, are 90° (in phase) apart from each other. When rotated
clockwise, in most encoders channel A leads channel B. To determine the leading
channel, refer to the encoder documentation or use an oscilloscope.
Connect the encoder output channel that leads when the drive runs Forward to BTAC
terminal A. Connect the output channel that trails to BTAC terminal B.
Option B: Functional test. For this test:
• Temporarily, switch the drive to the scalar mode [parameter 99.04 Motor ctrl mode
= 1 (SCALAR)].
• Run the drive in the forward direction.
• Verify that parameter 90.13 Enc1 revol extension increases in the positive
direction.
• If not, switch the A/A (or 1/1) connections.
Diagrams show normal phasing:
Pulse A leads (rises earlier than) pulse B.
90°
A or 1
A or 1
B or 2
B or 2