Run the following command to view device board information and identification details of all optical modules: show inventory The output includes the module type, serial number, Cisco-compatible part number, and other details, which are retrieved from the pre-programmed data in the. Run the following command to view device board information and identification details of all optical modules: show inventory The output includes the module type, serial number, Cisco-compatible part number, and other details, which are retrieved from the pre-programmed data in the. Every pluggable optical transceiver (SFP, SFP+, QSFP, QSFP28, etc. ) ships with a small EEPROM that stores two kinds of information: a fixed Serial-ID block (vendor, part number, serial number, capabilities) and—when provided—a diagnostics area (real-time temperature, voltage, TX/RX power, etc. EEPROM is a type of non-volatile memory, meaning it retains stored information even when the power is turned off. It allows data to be written, erased, and rewritten electrically. In optical transceivers, EEPROM provides a reliable way to store module-specific details that networking equipment can. The following introduces the specific operations to view the working status and internal information of an optical module on a Cisco switch. 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. SFF-8024 SFF Module Management Reference Code Tables : This specification provides codes for module identifiers, encoding values, connector types, extended compliance codes, host electrical interfaces and module media interfaces. When testing PRBS, there are 3 test nodes: MAC ----> PHY, PHY -----> MAC, and PHY ----- PHY. The specific viewing information is as follows:.