HLK-RM04 is a new embedded UART-ETH-WIFI module (serial port - Ethernet -Wireless network). This product is an embedded module based on the universal serial interface network standard, built-in TCP / IP protocol stack, enabling the user serial port, Ethernet, wireless network (wifi) interface between the conversions. Through the HLK-RM04 module, the traditional serial devices do not need to change any configuration; data can be transmitted through the Internet network. Provide a quick solution for the user’s serial devices to transfer data via Ethernet.