Phasing - ABB RTAC-01 User Manual

Chapter 3 – Installation

Phasing

3-6
When the encoder is connected correctly, running the
drive in the Forward (positive speed reference) direction
should produce a positive encoder speed feedback.
On incremental encoders, the two output channels,
usually marked 1 and 2 or A and B, are 90° (electrical)
apart from each other. When rotated clockwise, most
encoders – but not all – have channel 1 leading channel
2 as illustrated below. Determine the leading channel by
referring to the encoder documentation or by measuring
with an oscilloscope.
A or 1
A or 1
B or 2
B or 2
Z or 0
Z or 0
The encoder output channel that leads when the drive
runs Forward should be connected to RTAC input A, the
output channel that trails to RTAC input B.
The zero reference output channel (usually marked 0, N
or Z) needs to be connected in positioning applications
only.
RTAC-01 User's manual