Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set - Manual (Page 217)

Section 4C
Connecting the 4-axis Servo Module
4C-19
The servo module is equipped with a set of four LEDs located on the front
of the servo module. All four LEDs turn on, then off, at power up. All the
LEDs remain off during normal operation. If a servo fault occurs, the light
for the corresponding axis flashes. The servo fault may occur if the
module is not receiving feedback, or is receiving interrupted or irregular
feedback through the J1, J2, J3 or J4 connector.
A test point is a small metallic pin on the servo module’s circuit board.
There is one test point available in the servo module that you can use to
ground an oscilloscope during testing or troubleshooting. You can locate
this test point, TP6, with Figure 4C.14.
Figure 4C.14
Servo Module Test Point Location
TP6
TB1
P1
(CN1)
J1
J2
J3
P3
P2
TB2
4C.5.5
Servo Module LED
Indicators
4C.5.6
Servo Module Test Points