Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set - Manual (Page 618)

Section 11A
Connecting 1394 Digital Drive Systems
11A-13
If the correct voltages are not present at these test points, and incoming
power to the drive is turned on, contact your local Allen-Bradley sales
office for service information.
Two sets of LEDs are available on the 1394 drive CNC interface. One on
the system module, and one on each axis module.
System Module LED
The system module LED (labeled STATUS) is used to indicate the status of
the fiber optic I/O ring. If the LED is on (red) the fiber optic ring has
failed at some point before the 1394 system module. If it is flashing, the
fiber optic ring has failed at some point after the 1394 system module.
Axis Module LED
Each axis module has one LED visible from the front of the module
(labeled STATUS). Read this LED as follows:
Steady Green bus up, axis enabled
Flashing Green bus up, axis not enabled
Flashing Red/Green ready, bus not up
Flashing Red fault present
Steady Red hardware malfunction
11A.7
1394 LEDs