载波侦听多路访问。采用分布式控制方法，附接总线的各个结点通过竞争的方式，获得总线的使用权。只有获得使用权的结点才可以向总线发送信息帧，该信息帧将被附接总线的所有结点感知-Carrier Sense Multiple Access. A distributed control method, each attached to the bus node on a competitive basis, to obtain the right to use the bus. Only with the