Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set User Manual
Page 793

Section 15B
Replacement Procedures
15B-37
12. Reconnect all cables, then place the handle over the HPG interface
board and tighten the screw that holds the handle in place.
Bottom of HPG
Back of HPG
ON
1
2
3
Important: If incremental encoders are used instead of absolute encoders,
the servo module requires no batteries.
The digital servo module provides battery backup for the absolute encoder
position register. The absolute encoder position register provides position
data retention during power loss. The battery backup power originates
from the batteries plugged into the servo board at connector CN10.
Even if battery backup fails, or the encoder cable is temporarily
disconnected, the encoder will still maintain position data for up to 24
hours. This also allows for battery replacement without loss of
information.
Important: On the 9/230 Digital CNC the battery backup for the absolute
encoder originates from the battery on the processor board. This battery is
also used for axis data backup.
To replace the servo module battery:
1.
Turn OFF all power to the control.
ATTENTION: To guard against electrical shock hazards, never
make connections or disconnections at the AC distribution
network unless the main AC disconnect switch is open and locked.
Important: Wear an ESD wristband to prevent static discharge.
2.
Disconnect the old battery pack from connector CN10 on the 3-axis
servo module or connector P3 on the 4-axis servo module.
15B.22
Replacing the Battery
Backup for Absolute
Encoders on the Servo
Module