D220 is a Cat1 wireless data transmission terminal with an intelligent power supply design that passed the strict electromagnetic compatibility test and the experiment of withstanding more than the 7000V lightning strike. D220 product adopts dual serial channel mode and supports both RS232 and RS485 standard interfaces. It supports TCP/IP protocol, and transmission protocols, and utilizes a cellular network to realize transparent transmission of data information. It is suitable for single-chip data acquisition and transmission systems such as PLC or RTU, and industrial computers that use serial communication. D220 product is a new generation of 4G wireless DTU. It provides one RS232 and one RS485 universal interface. Wireless wide area network provides uninterrupted various network access capabilities, as well as comprehensive security and wireless services and other characteristics that help to digitalize information of the machine equipment. The design of this series of products fully meets the needs of unattended on-site communication. It adopts software and hardware watchdog and multi-level link detection mechanism to ensure the stability and reliability of communication. It supports the cloud management platform, which is convenient for users to manage remotely. Advanced software functions and a fully industrialized hardware design platform enable enterprises to quickly build large-scale industrial equipment networks with minimal investment.