标准摘要
[中文适用范围]： 1.1 概述 现场总线应用层 (FAL) 为用户程序提供了一种访问现场总线通信环境的方法。在这方面，FAL 可以看作是“相应应用程序之间的窗口”。本标准为自动化环境中的应用程序和 8 型现场总线特有的材料之间的基本时间关键和非时间关键消息传递通信提供了通用元素。术语“时间关键”用于表示存在一个时间窗口，在该时间窗口内，需要以某种确定的确定性完成一个或多个指定的操作。如果未能在时间窗口内完成指定的操作，则请求这些操作的应用程序可能会失败，从而对设备、工厂甚至人身安全造成风险。1.2 规范 本标准的主要目标是指定应用层协议的语法和行为，该协议传达 IEC 61158-5-8 中定义的应用层服务。次要目标是提供从先前存在的工业通信协议的迁移路径。正是后一个目标导致了 IEC 61158-6 系列中标准化协议的多样性。1.3 一致性本标准不规定单独的实现或产品，也不限制工业自动化系统内应用层实体的实现，一致性是通过实现本应用层协议规范来实现的。 [外文原描述]： IEC 61158-6-8:2007 provides common elements for basic time-critical and non-time-critical messaging communications between application programs in an automation environment and material specific to Type 8 fieldbus. It specifies interactions between remote applications and defines the externally visible behavior provided by the Type 8 fieldbus application layer. It defines the protocol provided to: define the wire-representation of the service primitives defined in IEC 61158 5-8, and define the externally visible behavior associated with their transfer. It specifies the protocol of the Type 8 fieldbus application layer, in conformance with the OSI Basic Reference Model (ISO/IEC 7498) and the OSI application layer structure (ISO/IEC 9545). This first edition and its companion parts of the IEC 61158-6 subseries cancel and replace IEC 61158-6:2003 and constitutes a technical revision. It includes the following significant changes from the previous edition: - deletion of the former Type 6 fieldbus for lack of market relevance; - addition of new types of fieldbuses; - partition of part 6 of the third edition into multiple parts. This bilingual version corresponds to the monolingual English version, published in 2007-12.
英文名称Industrial communication networks - Fieldbus specifications - Part 6-8: Application layer protocol specification - Type 8 elements