Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set - Manual (Page 469)

Section 9A
Operator Interface
9A-2
The monochrome and the color operator panels are powered by the
operator panel power supply. It supplies:
+12V dc power to the monochrome or color flat panel displays
+12 V dc power to the MTB panel I/O module
+5V dc power to the keyboard I/O ring interface
+5V dc power to the HPGs
The operator panel power supply receives power directly from the controls
main power supply.
The keyboard and softkeys on the operator panel are interfaced into the
9/Series I/O ring through the keyboard I/O interface. Fiber optic cables
connect the optical receiver (black) and optical transmitter (red) on the
operator panel keyboard I/O ring interface to the I/O ring. For more
information on fiber optic cables and connectors refer to page 7B-1.
Figure 9A.1 shows the different operator panels.