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The functional version of OSN1500 SSN1BA2 single board is N1.the single board is a 2-channel optical power amplifier board, which completes the amplification function of optical signals and is suitable for long-distance optical fiber transmission.When optical signals are transmitted over long distances, there is more signal attenuation, so in order to make optical receivers receive normal optical signals, it is necessary to add an optical power amplifier board (BA).The single board consists of an optical part, a drive and detection part, and a data processing and communication part.The single board can be inserted in slots 12 to 13 of the OptiX OSN 1500A subrack and slots11 to 13 of theOptiX OSN 1500Bsubrack.
Application Failure Scenario Description
The SSN1BA2 single board at a site reports an abnormal alarm, and the fault is resolved after adjusting the input optical wavelength to 1530nm-1560nm.
OptiX OSN 1500
OptiX OSN 1500
Failure category
PUM_BCM_ALM
OUT_PWR_ABN
OTHER
Phenomenon Description
The OptiX OSN 1500s at two sites A and B form a 1+1 Linear Multiplexing Segment for protection.The single boards at site A include: SLD4 single board, CXL4 (master and standby), and two BA2 single boards.The single boards at site B include: SLD4 single board, CXL4 (master and standby), and one BA2 single board.The SLD4 single boards have an optical interface of the type Ve-4.2, and the CXL4 single boards have the type L-4.1, and the BA2 boards output optical power of +14dBm.The OptiX OSN 1500s at sites A and B have a 1+1 Linear Multiplexing segment for protection. SLD4 single board optical interface type is Ve-4.2, CXL4 single board optical interface type is L-4.1, BA2 board output optical power are +14dBm. A, B two stations are 120km away from each other.
When the optical fiber is connected and tuned, it is found that the two BA2-S boards at station A have abnormal alarms PUM_BCM_ALM and OUT_PWR_ABN, and there is no alarm for the BA2-D board at station B.
Cause Analysis
PUM_BCM_ALM is the pump laser drive current overrun alarm. This alarm is generated when the drive current exceeds the built-in maximum operating current.
OUT_PWR_ABN is the output optical power abnormal alarm. This alarm is generated when the output optical power exceeds the output optical range (BA: +13dBm to +15dBm, PA: gain <19dB) when the input light is within the normal range (BA: -6 to +3dBm, PA: -36dBm to -10dBm), the operating current is not alarmed, and there is no adjustment. General possible causes are: aging or failure of the EDFA module, damage to the drive circuit or damage to the drive current detection circuit.
Operation Procedure
- Check the performance value of one BA2-S veneer board in station A with the network manager.
- In the main topology, select the network element of station A, right-click, and select "Network Element Manager".
- Select a BA2 board in the board list of the Element Manager.
- Select "Performance > Current Performance" in the function tree.
- In the right part, select "Physical Quantity", select "Luminous Power" and "Received Power", and select "Show Current Value" in "Options". In the "Options", select "Show Current Values".
- Click "Query".
- Analyzing the data, the input optical power of BA2 board is -2.6dBm, which is within the normal range (-6dBm to +3dBm), but the output optical power is +12.9dBbm, which is not within the normal range (+13dBm to +15dBm), so the OUT_PWR_ABN alarm is reported.The built-in maximum operating current of EDFA module is 138mA, but the actual operating current is 188mA, so the PUM_BCM_ALM is reported. The built-in maximum operating current of the EDFA module is 138mA, but the actual operating current is 188mA, so the PUM_BCM_ALM alarm is reported.
- Replace one BA2 board.
- Check the alarm on the network management. Find that OUT_PWR_ABN and PUM_BCM_ALM alarms are not canceled. Troubleshoot the single board.
- Check the fiber connection. It is found that the BA2 veneer at station A is connected to the CXL4 veneer. the output optical wavelength of the CXL4 veneer is 1280 nm to 1335 nm, which is not within the normal amplification range of 1530 nm to 1560 nm of the EDFA, and it cannot correctly amplify the input optical.
- Unplug the pigtail connecting the CXL4 veneer and the BA2 veneer.
- Connect the SLD4 veneer board and BA2 veneer board with the pigtail fiber.
- Query the current network element alarm. Abnormal alarms are automatically released.
Reference Information
Be sure to pay attention to the wavelength and power of the input optical signal and the power of the output optical signal and other related indexes of the BA2/BPA veneer in the engineering or maintenance.
The working wavelength of PA module is 1550.12nm, when its working wavelength deviates far from 1550.12nm, the input optical power value and the output optical power value will produce a large error. Its normal input optical power range is -36dBm ~ -10dBm, the input optical power is too large to reduce the service life of the laser, the input optical power is too small will lead to the EDFA module can not be amplified normally.
The input optical wavelength of BA module is 1530nm～1560nm, i.e. 1550nm window wavelength. If it is not within this range, the input optical signal cannot be amplified correctly, and the PUM_BCM_ALM alarm and OUT_PWR_ABN alarm may occur. In addition, the normal input optical power range of the BA module is from -6dBm to +3dBm; if the input optical power is not within this range, an input optical power abnormality alarm will be generated, and the service life of the laser may be reduced if the input optical power is too large.
The technical information in this chapter and the related SDH equipment troubleshooting procedures are provided by Shenzhen Optical Transmission Network Technology Co. Huawei SDH optical transmission equipment, SDH transmission equipment sales phone: 13430988088 Welcome to call!
