RS485总线信号反射分析及传感器采集系统设计

摘要

在目前的远距离通信、工业控制、智能化仪器仪表等领域中,常采用RS485总线通信方式.系统选用RS485芯片来实现多点传感器数据的采集.首先从理论上分析了远距离通信过程中电缆存在的反射过程,然后仿真验证端接匹配电阻可以很好地降低远距离通信时的信号存在的反射,设计了RS485总线通信主从硬件电路和上位机控制软件.试验表明:系统能够可靠稳定地实现远距离数据的采集.%In the current fields of long?distance communications,industrial control,intelligent instruments and meters and so on,RS485 bus communication mode was adopted.Thus,the system with RS485 chip achieved the acquisition of multipoint sensor data.First,this paper analyzed the cable reflection process of long distance communication from theory.Then,termination matching resistance can well reduce the long distance communication when there is reflection of signal process.The RS485 bus communica?tion master?slave hardware circuit and PC software control were designed. It is verified by experiment that system can realize steady reliable long?distance data collection process.