基于ModBus协议的高精度光栅位移测量仪设计

ModBus Protocol Based Design of High-Precision Grating Displacement Measurement Instrument

采用STC89C51单片机设计了基于ModBus协议的高精度光栅位移测量仪.根据光栅位移传感器的原理,设计光栅信号细分电路对光栅尺的输出信号精度进行提升,并用单片机的外部中断进行运动方向判别和位移测量,通过液晶显示结果;为了和AI系列仪表兼容,基于ModBus协议进行了485数据通讯设计.用LE型光栅尺在泡生法蓝宝石生长系统的应用结果表明其测量精度提高了4倍,具有较强的抗干扰能力,可实现多仪表的工业应用,具有传输距离远、传输速率快、稳定可靠的优点.

A ModBus protocol based high precision grating displacement measurement instrument was designed by using STC89C51 microcontroller in this paper.According to the principles of grating displacement transducer,a fractionized circuit for the grating signals was designed to achieve grating pulse interruption and motion direction identification for the singlechip with improved measurement precision,and then the measured results are presented with a LCD display.To enhance the compatibility with the AI series measurement meters,a 485 interface was also designed for data communication with computer based on the ModBus protocol.The experimental displacement measurement for kyropoulos sapphire growth using a LE Moire grating ruler proved that the precision was enhanced for 4 times with good ability of anti-interference and suggested the industrial application with long transmission distance,high data transfer rate and good reliability.