标准摘要
[中文适用范围]： 该部分IEC 61158标准为自动化环境中的应用程序之间提供了基于时间关键和非时间关键的消息传输的公共元素，并包含特定于第4型现场总线（Type 4 fieldbus）的材料。该国际标准定义了远程应用程序之间的交互，并以正式抽象语法、传输语法、应用上下文状态机和应用关系状态机来定义第4型现场总线应用层提供的外部可见行为。其目的是定义IEC 61158-5-4中定义的服务原语的线表示，并定义与其传输相关的外部可见行为。 [外文原描述]： IEC 61158-6-4:2019 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 2 fieldbus. The term “time-critical” is used to represent the presence of a time-window, within which one or more specified actions are required to be completed with some defined level of certainty. Failure to complete specified actions within the time window risks failure of the applications requesting the actions, with attendant risk to equipment, plant and possibly human life. This International Standard specifies interactions between remote applications and defines the externally visible behavior provided by the Type 2 fieldbus application layer. The purpose of this document is to define the protocol provided to a) define the wire-representation of the service primitives defined in this document, and b) define the externally visible behavior associated with their transfer. This document specifies the protocol of the Type 2 fieldbus application layer, in conformance with the OSI Basic Reference Model (ISO/IEC 7498-1) and the OSI application layer structure (ISO/IEC 9545). This third edition includes the following significant technical changes with respect to the previous edition: a) additional user parameters to services; b) additional services to support distributed objects; c) additional secure services.
英文名称Industrial communication networks - Fieldbus specifications - Part 6-4: Application layer protocol specification - Type 4 elements