Knowledge

When the switch on the third-party optical module cannot be recognized, the link is disconnected, or the alarm occurs, how to locate the root cause according to the five steps of "Identification-Optical Port-Wavelength-Link Budget-Firmware", with common brand coding and DDM threshold points attached.

When the code-writing custom module fails, the processing path is different from the standard product. This article explains how to use the batch number and coding test correspondence table to quickly delimit, which situations can be rewritten and restored, and which documents should be retained in daily procurement and operation and maintenance.

Divide batch coding orders into three clear steps from inquiry to listing, and mark the information and confirmation points that customers need to provide at each step. Customized coding orders can be placed correctly for the first time without rework.

Unrecognized ports, continuous alarms in logs, and distortion of DDM readings may all be caused by wrong code writing. This article summarizes the judgment methods of three typical symptoms to clarify which ones can be rewritten and recovered and which damage is difficult to reverse, so as to avoid a batch of modules becoming inventory losses.

Modules written correctly may still leave alarm lines in the switch log, most of which are related to DDM threshold interpretation. This article explains the threshold meaning of each monitoring item, common causes of false alarms and baseline recording methods, turning logs into executable maintenance signals.

Compatibility points of third-party optical modules organized by five mainstream switch brands: respective verification points, common pitfalls, and hardware matching boundaries of wavelength rates. Check them before purchasing, so that whether they can be used becomes something you can confirm before placing an order.

What the code changes is the identification area and alarm area of ​​the EEPROM chip on the module, and neither the circuit nor the firmware is affected. This article dissects what fields are stored in the A0 and A2 address pages, what is checked by the switch whitelist, and explains the nature of compatibility.

Modules with the same speed are divided into commercial grade and industrial grade. The price difference is mainly due to temperature design and materials. This article explains the meaning of the two temperature levels of 0-70℃ and -40-85℃, the risks of low-temperature startup and high-temperature power drift, and which scenarios must be industrial-grade.

Optical module specifications are densely packed with parameters. What really determines whether the link can be connected is the luminous power, receiving sensitivity and the loss budget between the two. This article uses an accounting method to explain clearly how to look at parameters and how to leave margins.

The single-fiber module uses one optical fiber for bidirectional transmission, which is achieved by staggering the wavelengths at both ends, so A/B must be used in pairs. This article explains the differences in transmission structures between single fiber and dual fiber, TX/RX wavelength pairing logic, and scenarios suitable for single fiber use.