Design Of Control System For Glass Substrate Automatic Testing Instrument Based On Double-layer Network

Today,the flat-panel display industry is booming.The requirements and system requirements of automatic optical testing instruments for glass substrates are increasing.And its motor control system determines the performance of the whole instrument.At present,almost all schemes adopt the combination of industrial computer,motion control card and PLC to realize.But the system has the disadvantages of high cost,cumbersome wiring,trouble of debugging and overhaul of the circuit.Therefore,this paper designed a wired and wireless distributed network control model,and completed the relevant hardware and software development.The control system includes three units: monitoring platform,acquisition control terminal and motor control terminal.As the host of Modbus network,the monitoring platform controls as a slave acquisition control terminal and motor control terminal.Acquisition control terminal includes Modbus ZigBee gateway and ZigBee terminal equipment.The gateway and ZigBee terminal devices communicate data through the ZigBee wireless network.In this paper,the hardware architecture of three large units is studied.And aiming at the monitoring platform and the motor control terminal,this paper proposes a control circuit board scheme with high-performance STM32F4 microcontroller as its core,and selects a chip system solution CC2530 integrated with RF and MCU for the acquisition control terminal,which has the characteristics of low cost and low power consumption.The hardware design uses the modular method,at the same time fully considers the industrial application request,selects the industrial grade chip,and carries on the isolation design to the input and output interface.In terms of software design,C language was used to write code at all levels of the software system to reduce the difficulty and cost of research and development.The ?C/OS-III real-time operating system and Modbus master-slave protocol stack were cut and transplanted on the STM32F4,and the Modbus slave protocol stack was ported to ZigBee protocol stack Z-Stack running on the CC2530.The communication protocols for this system were designed,including the communication protocol of motor control terminal and acquisition control terminal developed relying on Modbus protocol,as well as the communication protocol between Modbus to ZigBee gateway and ZigBee terminal node relying on Z-Stack and Modbus stack.The software of monitoring platform man-machine interface display and control,motor control terminal and acquisition control terminal were completed.The function of each unit of the control system is validated by cooperating with Modbus protocol debugging assistant and oscilloscope test.The results show that the design can satisfy the motion control requirement of the glass substrate automatic detection system.So this study is a useful exploration under the control of wired and wireless fusion.