Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set - Manual (Page 222)

Section 4C
Connecting the 4-axis Servo Module
4C-24
Figure 4C.16 shows an incremental feedback device equivalent circuit for
feedback channel A.
Figure 4C.16
Incremental Feedback Device Equivalent Circuit
Differential
Line Driver
Customer
Encoder
W W
A
A
Ch A HI
Ch A LO
Termination Panel
Servo Module
8500-TPC
Cable
+5V
316 215
68pf
Zenor
Protection
Encoder Return Optical Isolation
0V
+5V
0V
To Encoder Interface
Wiring Position Feedback
Feedback devices used with the control must be configurable such that the
marker Z is true at the same time that channels A & B are true. If you are
using an Allen-Bradley 845H encoder this requirement will already be met
if you wire them as shown in the cable diagrams on page 7A-28.
If you are using an encoder type feedback device other than the
Allen-Bradley 845H encoder, then use the following examples to
determine the correct wiring:
4C.7.1
Wiring an Incremental
Feedback Device