Eci Telecom NPT-1020 Installation And Maintenance Manual page 156

NPT-1020 Installation and Maintenance Manual
No. Symptom
N
OTE: An optical port with ALS capability turns off its transmitter when the corresponding
receive signal is lost. Turning the transmitter off may cause a chain reaction, which turns the
optical signals off in a whole section of the network and generates a large number of alarms.
As a result, it may be difficult to identify the real cause of the problem, and you may need to
use the management station log records to identify the port.
ECI Telecom Ltd. Proprietary
Probable cause
Corresponding optical
transmitter may have
been turned off by the
ALS function (see the
following note)
Corrective actions
Check that all the fibers are properly

connected to the corresponding optical
transceiver.
When available, select Maintenance >

Laser Management > Laser Switch > Force
Laser On in the LCT-APT to activate the
corresponding laser.
Use an OPM to measure the output optical

power. If the output optical power is not
within the range of minimum and
maximum levels specified in the NPT-1020
System Specifications during a 90-second
period, the problem is in the transmit side
of the transceiver. Remove and reinsert
the transceiver.
Check the output optical power again. If

the output optical power is still not within
the range of minimum and maximum
levels specified in the NPT-1020 System
Specifications, replace the transceiver.
If the problem persists, check the received

optical power with an OPM. If the optical
power is within the range of minimum and
maximum levels specified in the NPT-1020
System Specifications, replace the
transceiver.
If the problem persists after following the

previous steps, check the remote site.
If there are no problems on both sites, the

problem may be in the optical fiber
between the two sites.
N :
OTE Be sure to turn on the ALS function
after performing all checks.
Maintenance
7-10