Digital Diagnostic Function (DDM) for Optical Modules

        I.  digital diagnostic function
        We often say DDM, that is, the digital diagnostic function, literally understood as the working state of the optical module can be diagnosed, equivalent to the role of a doctor. It can provide the internal working status of the module to the host in real time, and can provide parameters including voltage, temperature, transmit optical power, receive optical power, bias current. The device can read and display the real-time operating parameters of the optical module through this function. Figure 1 shows the DDM detection data of our SFP-10G-LR on Cisco 9500 switch.

Figure 1 Real-time working status data of Moduletek SFP-10G-LR on Cisco 9500 switch

        II. Application of DDM Function
        2.1 Real-time Monitoring of Module Working Status
        The main function of digital diagnosis is to check whether the working environment of the module and its own working parameters are normal. Only in the standard-compliant environment, the performance of the optical module maintains the normal value. In some cases, the environmental parameters exceeding the datasheet or the relevant standards will cause the module's performance to degrade, thus resulting in transmission error codes. The working environment and the module is not compatible with the following: voltage exceeds the specified range; receive optical power overload or lower than the receiver sensitivity; temperature exceeds the operating temperature range and so on. The deterioration of the module's own performance may also lead to the emergence of transmit optical power becomes small, bias current exceeds the standard and other abnormal situations.
        2.2 Fault localization
        In an optical link, quickly locating where a fault occurs is critical to the business. Network administrators can use digital diagnostic information to determine some common network faults, such as link interruption faults caused by no received light. All optical modules produced by Motek have DDM function, and the reporting accuracy meets the requirements of international specifications. The physical diagram of our optical modules is shown in Figure 2 below.

Figure. 2  Optical Module Physical Diagram of Moduletek Limited

        If you have any questions about the above content, you can contact us by Email : web@moduletek.com