A common deviation in the acceptance of incoming materials is to only retest the transmit power and ignore the receiving end. When a short link is equipped with a long-distance module, bit errors will also occur if the light reception is higher than the overload point. This phenomenon is often not exposed until the equipment is put on the shelf. The receiving side needs to check both ways to be considered closed loop.

First estimate the link light intensity and then make a decision.

A rough calculation of attenuation based on fiber length and number of connectors: the single-mode 1310 band is about 0.35dB per kilometer. Adding the end and adapter losses, the total attenuation of an 800m intra-building link may be less than 1dB. Draw the nominal overload point and receiving sensitivity of the module into a window. The measured receiving angle is only safe in the middle of the window, and both top and bottom must be dealt with.

Retesting and handling of overload side

• Use an optical power meter to actually measure the light received at the opposite end. Be careful not to exceed the measuring range of the meter. If necessary, first perform series attenuation.
• When the light reception is higher than the overload point, add a fixed attenuator and try to find the appropriate position in steps of 3dB to 5dB.
• After adding attenuation, retest the bit error and DDM alarm thresholds to confirm that the sensitivity margin is not pushed to the limit.
• In the release scenario, you can continuously observe the switch light receiving log for about an hour before signing for acceptance. SeeData center high-speed interconnection solutionLink recording practices.

The sensitivity side also needs to be checked

Use adjustable attenuation to reduce the light collection to the sensitivity plus 2dB margin to see if the link can start flowing stably. Many warehouses will skip this step, but as a result, the chain will be broken occasionally after going online. Recommended for short distance within the rack10G DAC high speed cableResponsible, cross the computer room and then go upSFP+ 10G multi-mode dual-fiber optical module, a combination with high power at both ends makes it difficult to leave margin.

The overload margin, sensitivity margin, and measured light absorption should be stated on the acceptance form. EB-LINK technical support can help calculate the window based on the customer's actual link length. Tel: 0755-83179002.