Multifunctional OTDR devices designed for comprehensive testing of optical fiber and Ethernet networks. It integrates 12 key functions including Auto OTDR, Expert OTDR, event mapping, OPM, VFL, LS, and RJ45 cable diagnostics. It measures fiber length, loss, and connection quality with high accuracy, especially in short-distance and automatic tests. Features such as real-time event mapping, background multitasking, digital radar cable tracking, and end-face detection make it ideal for FTTX, backbone networks, and metro area network applications.