FINAL DRAFT - CISCO CONFIDENTIAL
10-4
CiscoONS 15216 EDFA2 Operations Guide
78-16033-01
Chapter10 Troubleshooting
Alarm Indicators
10.1.2 Optical Alarms
The ONS 15216EDFA2 amplifier has three main categories of alarms: optical (DWDM), equipment
(EQPT), and environmental (ENV). The optical alarms are directly related to the signal amplification
and are usually service affecting. The ONS 15216 EDFA2 has three Optical alarms:
•LOS
•GAIN
•LPOUT
Note Most optical failures are due to dirty or damaged co nnectors, so it is very important to clean all
connectors. Note that there is a connector inside the transmission equipment and that a problem may
come from there as well as from the patchcord.
Warning
Follow all directions and warning labels when working with optical fibers. To prevent eye damage,
never look directly into a fiber or connector.

10.1.2.1 LOS (Loss of Signal) Alarm

This alarm is generated when the input signal is below the value of LOSTH. The value of LOSHYST
provides the hysteresis required for the alarm to clear. Possible causes for this alarm are:
•Input power is below threshold value: Verify that the threshold value is set to the correct value for
the particular ONS 15216 EDFA2 application (RTRV-TH-DWDM). Read the input power using the
RTRV-DWDM command.
•No optical signal is present at the input (RTRV-DWDM): Verify that the transmitter is working
correctly and that the upstream fiber is not broken (RTRV-DWDM).
•Power meter value is higher than the reading of the ONS 15216 EDFA2 software: Clean connector
of fiber patchcord as well as the one from inside the ONS 15216 EDFA2 by removing the fiber
access panel.
Warning
Follow all directions and warning labels when working with optical fibers. To prevent eye damage,
never look directly into a fiber or connector.

10.1.2.2 GAIN (Gain Out of Range) Alarm

This alarm is only valid when the ONS15216 EDFA2 is in GAINTEMP mode. It occurs when the value
of OVERALLGAINMEASURED has deviated more than 1.25 dB from the manufac turer-defined set
point’s allowable range. This condition has a 0.25 dB hysteresis.
The GAIN alarm is also triggered if the value of INPWRDBM goes outside the manufacturer-defined
range by more than 0.7 dB. This condition has a 0.2 dB hysteresis.
Use the RTRV-DWDM command to retrieve the values of OVERALLGAINMEASURED and
INPWRDBM.
If both GAIN and LOS alarm conditions occur at the same time, only the LOS alarm is generated via
TL1. The GAIN alarm has a soak period of 1-2 seconds before being raised or cleared.