Wireless data transmission terminal DTU of Detailed introduction

Detailed introduction of wireless data transmission terminal DTU

The full name of DTU is a wireless data terminal of the Internet of Things, which uses the public carrier network to provide users with wireless long-distance data transmission. It adopts high-performance industrial-grade 8/16/32-bit communication processors and industrial-grade wireless modules, With embedded real-time operating system as the software support platform, it also provides RS232 and RS485 (or RS422) interfaces, which can be directly connected to serial devices to realize the function of transparent data transmission. 

　　 The four core functions of DTU: 

　　1) Internally integrated TCP/IP protocol stack

 DTU encapsulates the PPP dial-up protocol and TCP/IP protocol stack and has an embedded operating system. From the hardware, it can be regarded as a combination of embedded PC and wireless MODEM; it has the functions of dial-up Internet access and TCP/IP data communication . 

　　2) Provide two-way conversion function of serial port data 

DTU provides serial communication interfaces, including RS232, RS485, RS422, etc., which are commonly used serial communication methods, and most of the DTU designs serial port data into a "transparent conversion" method, which means that DTU can connect the serial port The original data is converted into TCP/IP data packets for transmission without changing the original data communication content. Therefore, DTU can be connected with various user equipments that use serial communication, and there is no need to modify the user equipment. 

　　3) Support automatic heartbeat, keep always online 

One of the advantages of the GPRS communication network is to support the permanent online of the terminal equipment. Therefore, the typical DTU is designed to support the permanent online function. This requires the DTU to include automatic dialing after power-on and the use of heartbeat packets to remain permanently online (when there is no data for a long time) During communication, the mobile gateway will disconnect the DTU from the center. The heartbeat packet means that the DTU and the data center send a small data packet before the connection is disconnected to keep the connection from being disconnected), support automatic reconnection after disconnection, and automatic Features such as redial.

 　　4) Support parameter configuration, permanent storage

 　　 As a kind of communication equipment, DTU has a wide range of applications. In different applications, the IP address and port number of the data center, the baud rate of the serial port, etc. are different. Therefore, DTU should support parameter configuration, and save the configured parameters in the internal permanent storage device (usually FLASH or EEPROM, etc.). Once powered on, it will automatically work according to the set parameters.

　　 The most basic usage of DTU is: Put a SIM card with GPRS enabled in DTU, register to the network after DTU is powered on, and then establish a connection with the data processing center through the network. This connection involves the wireless network operator, Internet broadband provider, the user company's network situation, and the user's computer configuration. Therefore, to establish this connection, all parts need to be configured.

　　 In essence, DTU and the data processing center establish a SOCKET connection. DTU is the SOCKET client, and the data processing center is the SOCKET server. SOCKET connection is divided into TCP protocol and UDP protocol. DTU and center must use the same protocol. This generally has configuration software for configuration.

　　DTU has now been widely used in power, environmental protection, LED information release, logistics, hydrology, meteorology and other industries. Although the applied industries are different, the principles of application are the same. Most of the DTUs are connected to industrial equipment, such as PLCs, microcontrollers and other automation products, and then establish a wireless communication connection with the background. Four-Faith DTU products have been widely used in power centralized meter reading, water meter centralized meter reading, heating network monitoring, gas monitoring, water conservancy monitoring, environmental protection testing, weather testing, earthquake monitoring, traffic control and other industries.