Run the display transceiver diagnosis interface [ interface-type interface-number ] command to view diagnostic information about a specified optical module. When certifying an optical module, Huawei comprehensively verifies the functions of the optical module to ensure the optical module quality. The functions include the installation and removal, transmit and receive power, signal transmission quality, basic information query, fault tolerance. Optical modules are widely used in switches, network interface cards (NICs), routers, and other communication devices.