User Manual

ADCP-75-110 • Issue 2B • July 2001
Page 52
© 2001, ADC Telecommunications, Inc.
16769-A
OPTICAL LOOPBACK
CONNECTION DETAIL
OPTICAL
TRANSCEIVER
OPTICAL
LOOPBACK
Figure 26. DRU Loopback Test
21. At the DHU or supporting DEU, place the PORT ON/OFF switch in the OFF position
(press O).
22. Remove the loopback and reconnect the optical fiber connectors (remove dust caps) to
the DRU optical port or remote DEU host port.
23. At the DHU or supporting DEU, place the PORT ON/OFF switch in the ON position
(press I).
24. Verify that the PORT OK/NOK LED turns green.
5.4.2 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 fiber link to be
tested in the OFF position (press O) if not already off.
3. Disconnect the optical connectors at the DHU or supporting DEU and at the
corresponding DRU or remote DEU.