8.2.4 Automatic Measurement and Control System for...
1.Basic Composition of the System
The system fully adopts the latest industrial measurement and control technologies such as intelligent distribution control,intelligent neural sensing network,plug and play(PnP),etc.The hardware platform uses embedded industrial computer as the basic monitoring center of the system,the vertical LCD screen with touch as the man-machine dialogue platform,PnP humidity sensor,temperature sensor,electric quantity collector,over-limit alarm and various state quantity collectors as input devices,and the ad hoc network wireless signal exchange module as the system information exchange channel.The control output module and contactor are used as output devices,and the alarm output system is composed of dial-up language alarm,buzzer and indicator lamp,etc.With the support of Linux operating system(front control computer)and environment measurement and control software,Windows operating system(background computer),Office suite,background Web release,video monitoring,telephone alarm and other professional software,the basic functions of real-time measurement,data acquisition,data processing,equipment control,man-machine dialogue and the like are realized.
The communication between it and sensors and control equipment adopts Zigbee wireless networking technology with international free ISM band 2.4G frequency,and the reliable point-to-point communication distance is about 30m without occlusion.Due to the networking technology,each terminal has routing(cascade)function,so as long as the distance between any two terminals does not exceed 30m,all devices in the network can communicate.
Network communication is adopted between the background client system and the intelligent control box,which can remotely view the environmental parameters and equipment operation conditions in the warehouse,remotely configure the warehouse parameters and remotely control the warehouse equipment.Multiple intelligent control boxes in the same place are connected to only one background client system through routers or switches.
The telephone alarm module is generally installed on the background client system.When an abnormality occurs in a warehouse,the background client system activates the telephone alarm function.There can be a maximum of 6 preset telephone numbers.
2.System Structure(https://www.daowen.com)
The structure of the warehouse environment automatic detection system is shown in Fig.8-7.
3.Unique Functional Features of the System
The front-end processor uses an industrial embedded host computer(Linux platform)to realize system data acquisition and system control.It can perform the most basic functions of the system,such as protection,measurement,control,etc.It switches the appropriate heater,dehumidifier and ventilator according to the set control rules.The control rules should be flexible and diverse.
The background workstation uses Windows platform for complex data processing and man-machine dialogue,can be networked with internal LAN,and supports querying warehouse temperature and humidity,varieties,quantity,specifications,collecting and testing conditions of tools and instruments through LAN.The system has excellent anti-virus features,supports Watchdogtimer and system mapping technology,and can recover itself quickly after program running-out or system breakdown,thus preventing the system from crashing and ensuring the stability and reliability of the system.
The manual/automatic controller has manual and automatic switch,which can realize manual or automatic control.In case of smoke and high temperature alarm,it can automatically cut off the control power supply of heater,dehumidifier,air conditioner and other equipment,and force open the ventilation device.