NK1000S series OTDR module provides a compact, cost-effective and high-performance card solution for optical cable monitoring system. The Ethernet port is used as the control interface for secondary development. The PC or embedded system sends the test command to the module and receives the returned results to complete all the work. The module can be embedded into the base station, optical fiber communication link, real-time remote monitoring of the health status of the optical cable, adopt new -online analysis and processing technologies, and carry out optical fiber engineering construction, maintenance for backbone network, metropolitan area network and access network, with excellent test and cost performance.