一种基于电力线的现场总线设计与仿真

Design and simulation for a power lines based fieldbus

针对国内建筑电气监控领域缺乏自主知识产权的现场总线技术,开发一种基于电力线的局域监控网络总线。总线由三根常规电力线构成,即火线、零线和数据线。火线与零线提供电源,而数据线共享零线为参考地,采用+/-30V的逻辑电平实现数据通信传输。基于电力传输线参数,建立总线驱动接口电路模型,对不同通信距离和节点数量下总线驱动性能进行仿真。结果表明,在通信波特率9 600 bit/s,距离1 000 m和250个节点应用条件下,总线电平信号跳变边沿约为数据位宽的10%,而接口转换得到的CMOS电平输入信号的完整性良好。总线结构简单,布线方便,可广泛用于智能建筑等领域,构建电气局域监控网络。

Aiming at lack of independent fieldbus technology in the field of domestic building electrical monitoring,a local monitoring network bus based on power lines is developed in this paper. The fieldbus consists of three conventional power lines： a fire line,a zero line and a data line. The fire wire and zero line is used to provide power supply,and the data line taking the zero line as reference ground and using ＋ /- 30 V logic level. Based on the parameters of conventional power transmission line,the bus driving interface circuit model is built and the bus driving performance is simulated under different communication distance and node number. The experimental results show that under the application condition of communication baud rate of 9600 bit / s,distance of 1 000 m and 250 nodes,the rising time and falling time of the bus level signal are both about 10% of the data bits width,and the signal integrity of CMOS input level obtained through interface conversion keeps prefect. Being of simple structure and convenience for wiring,the bus can be widely used for intelligent building for establishing electrical local monitoring network.