Design And Implementation Of The Industrial Data Acquisition System Based On LoRa

With the continuous progress and development of information technology,the application of information technology in the industrial field has become a trend.The "Industry 4.0" labeled with intelligent production has came quietly.The most important part of intelligent production is the collection and transmission of industrial field parameters.Because our country's existing data acquisition and transmission system generally has weak anti-interference ability in the industrial environment,it often results in inaccurate collection results due to external interference problems and may also cause module burn-out due to swarming into over-current and over-voltage,which directly increases the difficulty and the cost of system maintenance.In addition,some high performance data acquisition modules,whose high cost seriously hampers the popularization and application of data acquisition system in the production field.At the same time,there is a short transmission distance in the industrial wireless transmission technology at the present stage,which can not meet the higher requirements of intelligent manufacturing for long distance transmission.Therefore,aiming at the characteristics of the industrial field,a high-precision data acquisition system based on LoRa modulation technology is researched and designed in this thesis.The main work of this thesis are as follows.1.Research,design and implementation of high precision data acquisition module: At first,the factors that affect the accuracy of data acquisition and the corresponding anti-interference technology are studied.Secondly,the STM32F103 microprocessor is used as the control core and the 16 bit ADC AD7792 with high performance price ratio is also used.The software and hardware of the data acquisition module are designed by PCB isolation,differential transmission,power isolation,magnetic coupling isolation and input protection.The multi range data acquisition of 0~20mA,4~20mA current signals and 0~5V,0~10V,±5V and ±10V voltage signals is realized.Finally,the actual test results show that the effective number of the data acquisition module reaches more than 14 bits.2.Design and Implementation of a transmission module based on LoRa modulation technology and RS485 bus technology: Firstly,the STM8L151 microprocessor is used as the control core to complete the hardware and the software design of the transmission module with RS485 isolation protection chips and SX1278 RF chips.In addition,in order to increase the secondary development capabilities of the system,Modbus RTU protocol,a common industrial site,is selected as the communication protocol of the entire system,and the encapsulation of the Modbus message in the LoRa data frame is designed.Finally,the actual test showes that the data transmission module can wirelessly transmit more than 2000 meters without blocking,and it can also wirelessly transmit about 500 meters under bad conditions.3.Design and implementation of the upper computer interface: By using SKworkshop configuration software,the functions of real-time display of data,historical trend display,dynamic alarm,data storage and password protection are designed and realized on the human-computer interactive touch screen.