本推荐规程定义了铁路、地铁、轻轨和有轨电车等轨道交通系统中使用的重要计算机的功能、性能、接口和环境条件。 本推荐规程适用于车载和地面设备的重要计算机。 本推荐规程不适用于基于重要计算机开发的应用系统，且未定义应用系统的具体安全目标，但提出了应用系统的安全相关条件。 由于存在巨大的多样性，很难规范重要计算机的内部结构和技术实现。为了鼓励技术竞争，促进技术和工业的发展，本推荐规程不限制或推荐重要计算机的内部结构和技术实现。 本推荐规程仅在功能层面上定义了初步接口。 重要计算机的详细接口不包括在内，可以以外部接口规范的形式定义。 遵守本推荐规程的规定并不保证或确保安全、安保、健康或环境保护。用户有责任遵守所有适用的法律和法规要求。

This recommended practice defines the functions, performance, interface, and environmental conditions of vital computers used in rail transportation systems such as railways, metros, light transport, and trams. This recommended practice is applicable to vital computers for onboard and wayside equipment. This recommended practice is not applicable to the application systems which are developed based on vital computers and does not define specific safety targets for application systems, but the safety-related conditions for application systems are proposed. It is difficult to regulate internal structure and technical realization of vital computers, because of the great diversity that exists. In order to encourage technical competition and prompt the development of technology and industry, this recommended practice does not constrain or recommend the internal structure and technical realization of vital computers. Only the preliminary interface is defined in this recommended practice, on a function level. The detailed interface of a vital computer is not covered and can be defined in the form of external interface specifications. Compliance with the provisions of this recommended practice does not guarantee or ensure safety, security,health, or environmental protection. Users are responsible for observing all applicable legal and regulatory requirements.