User Manual

ADCP-75-179 • Preliminary Issue A • September 2004 • Section 4: maintenance
Page 4-17
© 2004, ADC Telecommunications, Inc.
15. At the transmitting HU or STM, place the On/Off switch in the OFF position (press O).
16. Disconnect the optical power meter from the receiver end of the optical fiber.
17. Reconnect the optical fibers to the receiving HU or STM.
18. Repeat steps 3 through 17 for each optical fiber that requires testing.
19. When ready to put the system back into service, place the On/Off switch in the ON
position (press I) at both the HU and STM.
20. Notify the NOC or alarm monitoring service that the system is going back online.
4.2 Optical Loopback Test
The following procedures provide tests to determine if an optical port fault exists with the Host
Unit or with the STM.
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 or STM (whichever unit is being tested), place the On/Off switch in the OFF
position (press O).
4. Disconnect the optical fiber connectors from the FWD (PORT 1) and REV (PORT 2)
optical ports and place a dust cap over each connector.
5. Plug a 15 dB in-line optical attenuator into the FWD (PORT 1) optical port as shown in
Figure 4-4.
Figure 4-4. Host Unit and STM Loopback Test
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.
HOST UNIT OR STM
1 METER PATCH CORD
15 dB
ATTENUATOR
20019-A
FWD
(PORT 1)
REV
(PORT 2)