提高RS-485总线实时性的一种方法  

A Method to Improve the Real-time of The RS-485

作　　者：刘伟联 

机构地区：[1]厦门万安智能股份有限公司

出　　处：《智能建筑》2011年第5期52-53,共2页Intelligent Building

摘　　要：RS-485总线因其具有简单高速、资源丰富、芯片价格低廉等特点，在工控领域得到了广泛应用。但其半双工的通信方式，使其信息的传递不够及时。这种工作方式限制了RS-485总线在一些对实时性、可靠性要求高的场合使用。本文提出了一种监听总线的方式，结合软件协议，实现了在RS-485总线上准多主设备方式，满足了系统可靠性、实时性的要求。The RS-485 bus is widely used in industry field for its good characteristic of simple ＆ high speed, rich resources and low-cost chips. But the messages-sending is not timely because of its half-duplex communication mode, thus make the RS-485 bus can not be used in fields which need high real-time and high reliability. This article raises one mode of Bus-Monitoring, and combining with software protocol, to realize multi-master permitted on RS-485 bus, and to satisfy the system requirements of high real-time and high reliability.

关 键 词：RS-485总线 半双工 总线冲突 多主发送 

分 类 号：TP336[自动化与计算机技术—计算机系统结构]