介绍一种由单片机 89C5 1构成的高精度多功能转速测试器的工作原理 ,设计思想 ,软硬件配置及应用方法。该测速器是通过采集光电编码器发出的脉冲信号由单片机记数 ,数据经内部程序计算、分析、处理后 ,按实际要求做出相应的继电器输出 ,模拟量输出和串行口输出。它的实时转速值通过 L ED显示非常方便直观 ,还可以通过按键显示瞬时转速值 ,事先设定的转速值。它具有超速报警与串行通讯口功能 ,还可以配接不同线数的光电编码器 (指编码器主轴旋转一周输出的脉冲数 ) ,实现高低转速值的测量。具有硬件结构简单 ,测量速度快 ,精度高 ,运行可靠等优点。 This paper introduces a working principle, design idea, hardware and software configuration and application method of a high-precision multi-function speed tester consisting of a single-chip microcomputer 89C51. The tachometer is through the collection of optical encoder pulse signal issued by the single-chip count, the data calculated by the internal procedures, analysis, processing, according to the actual request to make the corresponding relay output, analog output and serial port output. Its real-time speed through the L ED display is very convenient and intuitive, you can also press the button shows the instantaneous speed, speed value set in advance. It has speeding alarm and serial communication port functions, but also with a different number of optical encoder (refers to the encoder spindle output a week the number of pulses), to achieve high and low speed measurement. Has the advantages of simple hardware structure, measurement speed, high precision, reliable operation.