摘要
介绍了RS 485总线规范及其在远动信道监测及故障倒换中的应用,并针对负载节点过多或传输距离长的特点,提出了一种RS 485中继电路。对给出的电路原理图进行了分析,在硬件上实现了远距离和多负载情况下信号在RS 485总线上的有效传输。系统采用半双工串行通信方式,主机轮循对各个下位机进行访问,下位机收到上位机的命令后向上位机发送数据,给出了具体的下位机的软件流程图,同时也指出了在实际调试中应注意的问题。
In this paper,the standard of RS 485 bus and its applications in an channel detecting and accident switching are introduced,and in the situation of overfull load notes or overlong transmission distance,a repeat circuit of RS 485 is proposed. In this paper,the circuit diagram has been analysed,effective datum transmission using RS 485 bus has been realized on hardware in the situation of long distance and multi-load. The communication mode of this system is half-duplex. The host accesses every sub-system one by one and gets the datum. The detailed software flow chart is given in this paper and problems in debugging are pointed out at the same time.
出处
《现代电子技术》
2006年第17期104-105,108,共3页
Modern Electronics Technique
