The Design And Implementation Of Workshop's Industrial Parameters Management System Based On WiFi Wireless Network

With the rapid development of modern information technology,more and more factory equipment is developing in the direction of intelligence.In "Made in China 2025",it was mentioned that promoting manufacturing process intelligence to achieve structural changes and increased production,through the "Internet +" application.To comply with the development trend of the times,and to further strengthen corporate management,reduce work errors,improve work efficiency,ensure safe production,and so on.Existing wireless data collectors have incomplete functions and can only achieve a single function and high cost.This article is based on the implementation of wireless temperature and humidity monitoring in the workshop.By using the SCM technology and wireless communication technology,the design and implementation of the management system for temperature,pressure and flow detection parameters in the workshop are completed.In the wireless temperature and humidity monitoring system,a digital temperature and humidity sensor AM2302 with self-calibration function was selected to achieve the collection of individual temperature and humidity data.In the three major detection parameter management systems,the common output signal types of sensors that measure these signals are resistance,current,voltage,pulse frequency,and digital communication signals.According to the temperature measurement range,the temperature signal is measured by platinum resistance sensors and thermocouple sensors.The four-wire PT100 is used for platinum resistance temperature measurement.The resistance signal is measured by using a 0.5mA constant current source circuit and a differential amplifier circuit to convert the resistance signal into a voltage signal.The resistance value calculated is used to query the corresponding temperature value through the PT100 thermal resistance index table.In the thermocouple temperature measurement,the temperature measurement is the use of thermocouple temperature transmitter,which can output 4?20mA standard current signal.And it is connected to 4?20mA current signal to 0?3.3V voltage signal conversion circuit.First,it is converted into 1?5V using the resistor divider,and then it is converted into 0-3.3V through the subtractor,resistor divider and voltage follower.The output voltage signal is connected to the CPU pin,and then the resistance value is obtained through calculation,and the temperature value is obtained by querying the thermocouple index table.The sensors that measure pressure signals are mainly pressure transmitters and differential pressure transmitters.They are mainly 4-20mA current output signals,which is same with processing process of temperature transmitter output signal to obtain the current value,and then through the one by one Correspondences between current and pressure to calculated pressure values.According to the difference of the type of output signal of the flow sensor and the measurement principle,this paper can implement the three types of signal acquisition,including differential pressure type throttling device flow sensor(orifice flow meter),electromagnetic flowmeter,and vortex flowmeter.Differential pressure type throttling device flow sensor is mainly used differential pressure transmitter measurement,output 4?20mA current signal,converted to 0?3.3V voltage signal,and then through the software processing to obtain the current value,flow output in the flow calculation device difference The pressure needs to be calculated in squares,and the pressure and current are in a one-to-one correspondence,so the current output of the differential pressure transmitter is also calculated by square root.Electromagnetic flowmeter is usually 4?20mA or 0?10mA current output signal,and differential pressure throttling device sensor is different,its flow and current output is linear relationship,does not require open square calculation.The vortex flowmeter outputs a square wave vortex street flow signal,which is connected to the CPU pin and realizes the frequency or period measurement through the timer input capture function of the STM32.The interface of common digital communications for industrial equipment is mainly the application of RS485 communication interface,which is connected to the STM32 serial port.The wireless communication of the acquisition card adopts the low-power USR-WiFi232-T wireless module produced byJinan USR IOT.In combination with the LEGUANG A330 wireless router,it can realize stable and fast wireless communication between the host computer and the wireless data acquisition card.The hardware driver of the wireless data collector is implemented in the Keil uVision4 programming environment by using C language as the development language.It can achieve many data acquisition and data transmission functions,such as parameters configuration,GPIO and serial port configuration,AD acquisition,timer input capture,key interrupt operation,RS485 communication interface configuration,and so on.The upper computer's management platform is implemented with LabVIEW graphical programming software.The operation interface is simple and user-friendly.It not only realizes the functions of user registration,data display,analysis and statistics,but also adds functions such as super value alarm.And it can save historical data to the Access database,it is convenient for users to view and manage historical data.The system has a simple principle,convenient operation,low cost,high reliability and high practical value.It is believed that it will be more widelyused in the near future.