IEC 61158-6-20:20 14定义了协议，该协议用于定义IEC 61158-5-20中定义的服务原语的有线表示，并定义与其传输相关联的外部可见行为。本标准规定了20型现场总线应用层的协议，符合OSI基本参考模型（ISO/IEC 7498-1）和OSI应用层结构（ISO/IEC 9545）。本第三版取消并取代2010年出版的第二版，构成技术修订。主要变化有: -添加到IEC 61158-5-20的新服务的附加协议； -增加了规范性附件； -随后更新的参考文献、术语、定义、符号、缩写； -更正编辑错误和案文。

IEC 61158-6-20:2014 defines the protocol provided to define the wire-representation of the service primitives defined in IEC 61158-5-20, and define the externally visible behavior associated with their transfer. This standard specifies the protocol of the Type 20 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 cancels and replaces the second edition published in 2010 and constitutes a technical revision. The main changes are:
- added protocol for new services that are added to IEC 61158-5-20;
- added normative annexes;
- updated then references, terms, definitions, symbols, abbreviations;
- corrected the editorial errors and the text.