[Introduction]：E840-DTU (EC05-485)E is a small-sized 4G DTU developed by Chengdu Ebyte Electronic Technology Co., Ltd. using 4G CAT1 technology for use in the Asia-Pacific region, Australia, New Zealand and other regions. It has small size, high speed, low latency It is low cost and easy to use. Simple configuration can realize the serial port device networking function (two-way transparent transmission between the serial port device and the network server). The product uses 2.54 spring crimp terminals and supports installation on guide rails and positioning holes. Simple configuration can realize the serial port networking process, which is very convenient to integrate into Internet of Things projects.