Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set - Manual (Page 162)

Section 4B
Connecting the 3-axis Servo Module
4B-16
The optional feedback module provides extra feedback ports for the digital
servo module. Use these ports to provide axis position feedback to the
digital servo module from a non-motor mounted second feedback device.
When using an optional feedback module, the incremental or absolute
encoder mounted on the digital servo motor provides current and velocity
loop feedback while a non-motor mounted feedback device provides axis
position feedback.
Figure 4B.14
Optional Feedback Module
CN16F
CN15F
CN14F
VR2
VR1
VR3
CN21M
CN22M
CN23M
CN24M
CN25M
JP1
11861-I
Figure 4B.15 shows the optional feedback module mounted to and
interfaced with the digital servo module through connectors CN21M and
CN22M. Typically the optional feedback module receives +5V dc power
from the main power supply through connector CN25M. This +5V dc
power is then transferred from connector CN24M on the optional feedback
module to connector CN13 on the digital servo module using the cable
supplied with the optional feedback module.
4B.3
Optional Feedback Module