Use the display transceiver and display transceiver diagnosis commands to view optical module power and attenuation on Huawei CE switches.

Viewing Optical Module Information

To check optical attenuation, you first need to view the optical module's transmit (Tx) and receive (Rx) power:

• Command for all ports: display transceiver This shows basic information for all optical modules, including type, wavelength, and DDM support .
• Command for a specific interface: display transceiver interface <interface-type> <interface-number> This provides detailed information for a specific port, including Tx and Rx power, module type, connector type, wavelength, and transfer distance .
• Verbose output for power details: display transceiver interface <interface-type> <interface-number> verbose This displays the actual transmit and receive power values, high/low thresholds, and other diagnostic parameters .

Using Digital Diagnostic Monitoring (DDM)

Huawei optical modules support DDM, which allows real-time monitoring of:

• Transmit power (Tx)
• Receive power (Rx)
• Temperature
• Voltage
• Bias current To view DDM data, use: display transceiver diagnosis interface <interface-type> <interface-number> This command provides the digital diagnostic monitoring information, which is essential for calculating optical attenuation and verifying that the module operates within safe limits .

Interpreting Optical Attenuation

Optical attenuation can be inferred by comparing the transmit power of the local module with the receive power at the remote module:

• Attenuation (dB) = Tx power (dBm) - Rx power (dBm)
• If the Rx power is below the low threshold, the fiber may be too long, or the fiber attenuation is high .
• If the Rx power is above the high threshold, the module may be overloaded or the fiber is too short.

Additional Considerations

• Ensure that local and remote modules match in type, wavelength, and rate; mismatched modules can prevent the link from coming up .
• Check that the fiber type and length are within the module's supported transmission distance. For example, 850 nm multimode modules are typically short-distance, while 1310 nm single-mode modules support medium to long distances .
• Use Huawei-certified optical modules to avoid abnormal power readings or interface issues . By following these steps, you can accurately monitor optical attenuation, verify link quality, and troubleshoot CE switch optical interfaces effectively.