Digital Diagnostic Monitoring (DDM), also commonly termed Digital Optical Monitoring (DOM), is a standardized feature for pluggable optical transceivers that provides real-time digital telemetry of critical internal parameters — including transmit optical power (TX), receive. Digital Diagnostic Monitoring (DDM), also commonly termed Digital Optical Monitoring (DOM), is a standardized feature for pluggable optical transceivers that provides real-time digital telemetry of critical internal parameters — including transmit optical power (TX), receive. Digital Diagnostics Monitoring (DDM), also known as Digital Optical Monitoring (DOM) or Diagnostic Monitoring Interface (DMI), is a standardized feature defined by SFF-8472 that allows network devices to monitor real-time optical transceiver parameters such as temperature, voltage, transmit power. This guide uses the Moduletek SFP-25G-SR optical module connected to a Cisco C9300 switch as an example. Figure 1 Schematic Diagram of Optical Module Connected to Switch 1. Check Optical Module and Port Status Execute the following command to view detailed interface and optical module status: show. When the optical module on an interface is faulty, you can run the display commands to view information about the optical module. Related Information Video Identify a Huawei-Certified Optical Module Run the display transceiver [ interface interface-type interface-number | slot slot-id ] [ verbose ]. This article provides instructions on how to view the Optical Module Status on your switch through the Command Line Interface (CLI). The Cisco Small Business Series Switches allow you to plug in a Small Form-factor Pluggable (SFP) transceiver in their optical modules to connect fiber optic cables. DDM is not merely a feature; it is an industrialized standard. DDM (Digital Diagnostics Monitoring) is a feature that is included in optical modules, such as SFP, SFP+, QSFP, and QSFP+ transceivers.