User's Manual Part 2

ADCP-75-187 • Preliminary Issue 1B • November 2005 • Section 4: MAINTENANCE
Page 4-11
© 2005, ADC Telecommunications, Inc.
4 TEST PROCEDURES
This section provides procedures for common troubleshooting and maintenance tests. Refer to
these procedures as needed when specified in the Fault/Alarm Isolation Diagrams in Section 3.
4.1 Optical Power Test
A break in an optical fiber or a fault with the optical connector will interrupt communications
between linked components or generate excessive errors. Use the following procedure to isolate
a problem with an optical fiber or connector.
1. Put on the IR filtering safety glasses.
2. Notify the NOC or alarm monitoring system operator that the system is going offline.
3. At the HU, place the On/Off switch in the OFF position (press O). At the RU, place the
AC circuit breaker switch in the open (OFF) position.
4. Disconnect the optical fiber connectors for the fiber to be tested at the HU and the RU.
5. Inspect the optical connectors. Verify that connectors are clean and that no scratches or
imperfections are visible on the fiber end. Clean and polish the optical connectors if necessary.
6. Connect the optical power meter to the output (receiver) end of the optical fiber as shown
in Figure 4-2. If an attenuator was included in the fiber link, make sure it is installed.
Figure 4-2. Forward and Reverse Path Optical Fiber Test Set Up
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 transmitter of any 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 transmitter or optical fiber connector to avoid the
potential of dangerous amounts of radiation exposure. This practice also prevents dirt particles
from entering the connector.
Note: Turning off the HU and RU disables the respective lasers which is necessary in
order to safely inspect and clean the optical connectors.
HOST UNIT
FWD
(PORT 1)
REV
(PORT 2)
BAND 2 BAND 1
ATTENUATOR
(IF USED)
ATTENUATOR
(IF USED)
FWD/REV PATH
OPTICAL FIBER
FWD/REV PATH
OPTICAL FIBER
-15 TO -25 dBm
-15 TO -25 dBm
FORWARD PATH OPTICAL FIBER
TEST SET UP
REVERSE PATH
OPTICAL FIBER TEST SET UP
20979-A
REMOTE UNIT
OPTICAL POWER
METER
OPTICAL POWER
METER
WDM
WDM
2
3
3
SEE TAG ON PORT TO IDENTIFY SYSTEM