标准摘要
[中文适用范围]： 该标准是为促进自动化系统组件互连而制定的一系列标准之一。它与 IEC/TR 61158-1:2010 中描述的三层现场总线参考模型定义的集合中的其他标准相关。该标准包含特定于 Type 21 通信协议的材料。 [外文原描述]： IEC 61158-6-21:2010(E) specifies the protocol of the Type 21 fieldbus application layer, in conformance with the OSI Basic Reference Model (ISO/IEC 7498-1) and the OSI application layer structure (ISO/IEC 9545). It defines the protocol provided to define the wire-representation of the service primitives defined in IEC 61158-5-21:2010, and the externally visible behavior associated with their transfer. This standard cancels and replaces IEC/PAS 62573 published in 2008.
英文名称Industrial communication networks - Fieldbus specifications - Part 6-21: Application layer protocol specification - Type 21 elements