Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set - Manual (Page 223)

Section 4C
Connecting the 4-axis Servo Module
4C-25
Figure 4C.17
Examples of a Correct and Incorrect Encoder Wiring
A +
A--
B+
B--
Z+
Z--
A +
A--
B+
B--
Z+
Z--
A +
A--
B+
B--
Z+
Z--
A +
A--
B+
B--
Z+
Z--
A +
A--
B+
B--
Z+
Z--
A +
A--
B+
B--
Z+
Z--
A +
A--
B+
B--
Z+
Z--
A +
A--
B+
B--
Z+
Z--
Control Encoder
Control Encoder Control Encoder
Control Encoder
Correct Encoder Wiring -
results in expected motion
Incorrect Encoder Wiring -
results in unpredictable motion
Incorrect Encoder Wiring -
results in a servo fault
Incorrect Encoder Wiring -
results in expected motion
Important: Since positive and negative axis directions can be assigned
without regard to encoder rotation directions, it is possible for the feedback
direction to be “backwards”. This is easily corrected before attempting to
command axis motion through the AMP parameter Sign of Position
Feedback. Refer to your AMP reference manual for more information.