The M series is the main module of XIO. It supports dual Ethernet ports and RS485 expansion slave stations. It can access up to 7 S series expansion modules and can efficiently manage the slave stations, including online status, data collection and remote control. In most areas where programmed control is not required, the M series master module can be used as a direct replacement for the DDC controller. The module supports standard BACnet IP, Modbus TCP, HTTP and other protocols. It is suitable for control systems with pure Ethernet architecture. The control box is used as a unit. The expansion slave station is connected through the RS485 of the M main module in the box. The control boxes use High-speed Ethernet connection. It can effectively reduce the usage of DDC controller or network controller, and effectively reduce project costs while ensuring stability and efficiency. The M series includes 4 models: XIO-16M, XIO-12M, XIO-8RM, and XIO-8UM.