Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set - Manual (Page 203)

Section 4C
Connecting the 4-axis Servo Module
4C-5
The functions of the servo module are designed to make the axes run with
optimum performance. Generally, the maximum feedrates are limited by
the mechanical abilities of the machine. System gain and the maximum
allowable following error will also limit the feedrates. These limits are
entered as AMP parameters. Refer to the 9/Series CNC 9/230, 9/260, and
9/290 AMP Reference Manual, publication 8520-6.4, for more
information.
There are two typical analog servo drive configurations for the control.
The typical mill configuration has three axes, each having a servo motor
and feedback device, and an open loop spindle motor. The typical lathe
configuration has two axes, each having a servo motor and feedback
device, and an open loop spindle motor with position feedback.
This servo module functions as a high speed servo processor. It is installed
in the component enclosure. The servo amplifier amplifies the signal from
the servo module in order to deliver the power necessary to drive the servo
motors.
Position and velocity data are read from a feedback device that is mounted
on the slide, ballscrew, or servo motor. This feedback device generates
differential signals that are then fed to the servo module. If the spindle
motor incorporates an encoder it will supply spindle position feedback to
the servo module.
4C.3
How the Analog/1394 Servo
Module Works