GB/T 15127-2008 in English

《GB/T 15127-2008信息技术 系统间远程通信和信息交换 双扭线多点互连》由TC28（全国信息技术标准化技术委员会）归口，主管部门为国家标准化管理委员会。
本标准对下述几方面，规定物理媒体特性：
ａ）对两线或四线网络拓扑中的双扭线多点互连，分别提供半双工或全双工数据传输能力；
ｂ）互连端点系统的二进制信号和双向信号传送；
ｃ）端点系统分支电缆和可长达1200m 的公共干线电缆的电气和机械设计；
ｄ）端点系统范围内集成电路型的发生器和接收器的部件测量；
ｅ）可适用的数据信号速率高达１２．５ Ｍｂｉｔ／ｓ。
所定义的电气部件特性和测量与ＧＢ／Ｔ７６１９给出的双扭线点到点的特性非常一致。
本标准不描述完整的物理接口，亦不描述功能接口特性，如：
ａ）互换数据电路和控制电路的数目；
ｂ）端点系统分支电缆连接器的类型、尺寸和插针分配；
ｃ）数据和控制信号编码；
ｄ）互换电路上信号间的时间关系；
ｅ）同步或异步的传输方式；
ｆ）发送和接收的信号质量。
本标准不规定特殊的环境条件，如电流绝缘、电磁干扰（ＥＭＩ）、射频干扰（ＲＦＩ）以及人员安全。这些可能会构成未来补篇的课题。
本标准主要是部件规范，对所有可能配置中满意地互操作规定不够充分，确保其预期配置能满意互操作是实现者的责任。
本标准可以同任何适当的一组功能和附加环境特性结合，以满足局域网或广域网领域中的实际数据传输要求。

Scope

1.1 This standard specifies the physical media characteristics for the following aspects: a) Provide half-duplex or full-duplex data transmission capability for twisted pair multi-point interconnection in two-wire or four-wire network topology, respectively; b) Two-way signal and two-way signal transmission of the interconnection terminal system; c) Electrical and mechanical design of branch cables of the terminal system and public trunk cables up to 1200m; d) Design of integrated circuit type generators and receivers within the scope of the terminal system Component measurement; e) Applicable data signal rate up to 12.5Mbit/s. 1.2 The defined characteristics and measurements of electrical components are very consistent with the point-to-point characteristics of twisted pair wires given in GB/T 7619. 1.3 This standard does not describe the complete physical interface, nor does it describe the functional interface characteristics, such as: a) the number of interchangeable data circuits and control circuits; b) the type, size and pin assignment of the terminal system branch cable connector; c) Coding of data and control signals; d) Time relationship between signals on interchanged circuits; e) Synchronous or asynchronous transmission mode; f) Quality of transmitted and received signals. 1.4 This standard does not specify special environmental conditions such as galvanic isolation, electromagnetic interference (EMI), radio frequency interference (RFI), and personnel safety. These may form the subject of future supplements. 1.5 This standard is mainly a component specification, and it is not sufficient to specify satisfactory interoperability in all possible configurations. It is the responsibility of the implementer to ensure that the expected configuration can be satisfactorily interoperable. 1.6 This standard can be combined with any appropriate set of functions and additional environmental features to meet the actual data transmission requirements in a local area network or wide area network.