User Manual

ADCP-75-136 • Issue 1 • November 2002
Page 51
© 2002, ADC Telecommunications, Inc.
17282-A
OPTICAL LOOPBACK
CONNECTION DETAIL
OPTICAL
TRANSCEIVER
OPTICAL
LOOPBACK
Figure 27. DRU Loopback Test
21. The DRU STATUS LED or DEU HOST LED will turn either blinking red or green. If
the LED turns blinking red, the optical port is faulty and the optical transceiver must be
replaced. If the LED turns green, the optical port is good.
22. At the DHU or supporting DEU, place the PORT ON/OFF switch in the OFF position
(press O).
23. Remove the loopback from the DRU optical port or remote DEU host port.
24. Clean the optical fiber connectors and then reconnect the optical fibers to the DRU
optical port or remote DEU host port.
25. At the DHU or supporting DEU, place the PORT ON/OFF switch in the ON position
(press I).
26. Verify that the PORT OK/NOK LED turns green.
6.4.2 Optical Loss Test Procedure
A break in an optical fiber or a fault with the optical connector will interrupt communications
between linked components. Use the following procedure to isolate a problem with an optical
fiber or optical connector:
Danger: This equipment uses a Class 1 Laser according to FDA/CDRH rules. Laser radiation
can seriously damage the retina of the eye. Do not look into the ends of any optical fiber. Do
not look directly into the optical transceiver of any digital unit or exposure to laser radiation
may result. An optical power meter should be used to verify active fibers. A protective cap or
hood MUST be immediately placed over any radiating transceiver or optical fiber connector
to avoid the potential of dangerous amounts of radiation exposure. This practice also prevents
dirt particles from entering the transceiver or connector.
1. Put on the IR filtering safety glasses.
2. At the DHU or supporting DEU, place the PORT ON/OFF switch for the optical fiber to
be tested in the OFF position (press O) if not already off.