User Manual

ADCP-75-110 • Issue 2B • July 2001
Page 51
© 2001, ADC Telecommunications, Inc.
7. Place the PORT ON/OFF switch in the OFF position (press O).
8. Disconnect the loopback from the DHU or supporting DEU and reconnect the optical
fiber connectors (remove dust caps) to the optical port.
9. Disconnect the optical connectors at the DRU optical port or remote DEU host port (far
end of fiber).
10. Connect the loopback (requires LC adapters) to the optical fiber connectors.
16768-A
OPTICAL
ADAPTER
OPTICAL
LOOPBACK
OPTICAL
CONNECTOR
Figure 25. Optical Fiber Loopback Test
11. Insert a dust plug into the DRU optical port or remote DEU host port.
12. At the DHU or supporting DEU, place the PORT ON/OFF switch in the ON position
(press I).
13. The PORT OK/NOK LED will turn either red or green. If the LED turns red, one of the
optical fibers is faulty. Refer to Subsection 5.4.2 to isolate which fiber is at fault. If the
LED turns green, the optical fibers are good. Proceed to step 14 to finish the test
procedure.
14. At the DHU or supporting DEU, place the PORT ON/OFF switch in the OFF position
(press O).
15. Disconnect the loopback and the optical adapters from the optical fiber connectors.
16. Place a dust cap over the connector for each optical fiber
17. Remove the dust plug from the DRU optical port or remote DEU host port.
18. Plug the loopback into the DRU optical port or DEU host port.
19. If testing a DRU that is powered by the DHU or by a supporting DEU, place the PORT
ON/OFF switch in the ON position (press I).
20. The DRU STATUS LED or DEU HOST LED will turn either red or green. If the LED
turns red, the optical port is faulty and the unit must be replaced. If the LED turns green,
the optical port is good.