Cisco Systems 15216 EDFA2 Optical Alarms, LOS Loss of Signal Alarm, Gain Gain Out of Range Alarm

Chapter 10 Troubleshooting

Alarm Indicators

F I N A L D R A F T - C I S C O C O N F I D E N T I A L

10.1.2 Optical Alarms

The ONS 15216 EDFA2 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 connectors, 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 ONS 15216 EDFA2 is in GAINTEMP mode. It occurs when the value of OVERALLGAINMEASURED has deviated more than 1.25 dB from the manufacturer-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.

Cisco ONS 15216 EDFA2 Operations Guide

10-4 78-16033-01