What optical power monitoring really focuses on is the margin, which is the difference between the measured light reception and the module reception sensitivity. It determines how much additional loss the link can withstand. Divide the margin into three-level thresholds and write them into the duty manual, so that the duty personnel know when to just register and when to take action.
Baseline establishment should be done after the link is stable.
The baseline should be collected after the end face is cleaned, the jumpers are straightened out, and the equipment is running at full load for a period of time. Record the two sets of data of the originating and receiving ends port by port, and indicate the module model and nominal distance. Do not write different distance ranges on the same page for comparison, for exampleSFP+ 10G single-mode dual-fiber 10km optical moduleIt is different from the normal lighting range of the long-distance gear, and it is easy to mistake normal for dark when mixed. It is recommended that both parties sign the baseline form, which serves as the starting point for all subsequent disputes.
The three-level threshold plus a reverse threshold
- Attention level: The margin is about 1 dB lower than the baseline. It is only registered but not processed. The next inspection and review will be arranged.
- Alarm level: The margin is less than 3 dB. Check the jumper routing and end face on the same day, and perform a cleaning and re-inspection if necessary.
- Mobile level: If the margin is less than 1 dB or the light is close to the sensitivity, immediately replace the jumper, module or adjust the distance gear.
- Overload level: Excessive light reception on short-distance links also requires trigger processing. Usually, fixed attenuation is added instead of removing the link and redoing it.
Looking at trends can reveal hidden dangers better than looking at single points
It is recommended to export module self-reported data once a month to calculate the degradation rate of each port. The annual drift of a normal link is generally within one decimal place; if a port drops by more than 0.2 dB per month, it is probably because the connector is damp, the jumper is repeatedly bent, or the module is aging. By the time it hits the threshold, the buffer time has been lost. EB-LINK technology supports the use of this column rate, rather than the single reading itself, to determine the priority order when doing baseline return visits at multiple sites. Writing the rate into a fixed column of the monthly report is much more effective than flipping through the record book temporarily.