The DIDO expansion module is an analog acquisition and control module based on the RS-485 network. It is mainly used in conjunction with a centralized controller and installed in a power distribution cabinet. It can provide 8 switching inputs, 8 relay outputs, and embedded system modules. The data collector adopts standard guide rail installation method, which is simple and quick to install on site. Corresponding functional modules can be quickly added according to project requirements to meet the needs of street lamp terminal intelligent management, flexible configuration and high availability, to achieve terminal data collection, monitoring, etc., with good scalability and adapt to various field applications.