指定2线或4线网络拓扑中双绞线多点互连的物理介质特性、二进制和双向信号传输、端点系统分支电缆的电气和机械设计以及长度可达1200 m的公共主干电缆，端点系统内集成型发生器和接收器的组件测量，适用的数据信令速率高达12.5 Mbit/s。

Specifies the physical medium characteristics for twisted pair multipoint interconnections in either 2-wire or 4-wire network topology, a binary and bi-directional signal transfer, the electrical and mechanical design of the endpoint system branch cables and the common trunk cable which may be up to 1200 m in length, the component measurements of the integrated type generators and receivers within the endpoint system, the applicable data signalling rate up to 12,5 Mbit/s.