IEC 61158-1:2019

Overview - IEC 61158-1:2019 (Fieldbus overview and guidance)

IEC 61158-1:2019 is the second edition (technical revision) of the IEC guidance document that defines the generic concept of fieldbuses for industrial communication networks. It provides an organized overview of the IEC 61158 family and explains how to use parts of IEC 61158 together with the IEC 61784 series. The document maps fieldbus concepts onto the ISO/IEC 7498-1 OSI Basic Reference Model, describes common concepts used across type-specific parts (physical, data‑link and application layers), and explains application layer service description concepts and generic fieldbus data types. This edition also updates references across related standards and adds Type 25 and Type 26 fieldbus types and their profile families (CPF 20 and CPF 21).

Key topics and technical coverage

• Structure and scope of IEC 61158: Guidance on how the series is organized into layer-specific parts (physical, data-link, application).
• Mapping to the OSI model: How fieldbus layers correspond to the OSI Basic Reference Model (ISO/IEC 7498-1).
• Layer separation: service vs. protocol: Distinction between service descriptions and protocol specifications for the Data‑link Layer (DL) and Application Layer (AL).
• Application Layer concepts: Fieldbus Application Layer (FAL) architecture, application processes, Application Process Objects (APOs), ASE (Application Service Elements) and management of objects and naming/addressing.
• Generic fieldbus data types: Data type ASE and mechanisms for user-defined types and transfer of user data.
• Summaries for fieldbus Types: Physical, data-link and application layer characteristics for multiple fieldbus Types (including newly added Types 25 and 26).
• Profiles and CPF (Communication Profile Families): Structure of CPFs and relationship with IEC 61784 profiles (including safety and installation profiles).
• Guidance for implementers: Supported options, benefits of formal descriptions, media selection (Annex B) and guidance for wireless and safety-related communication.

Practical applications and target users

Who uses IEC 61158-1:2019:

• Fieldbus implementers and device vendors - to structure protocol implementations and ensure interoperability.
• System integrators and automation engineers - for selecting appropriate fieldbus types and CPFs for control systems.
• Standards and QA teams - to align product documentation, testing and conformance strategies.
• Safety and wireless specialists - to understand integration of functional safety profiles (IEC 61784-3) and wireless considerations.

Practical value:

• Facilitates interoperability among fieldbus devices and profiles.
• Helps map vendor technologies to a common OSI-based model.
• Guides selection of physical media, profiles and data types for industrial control networks.

Related standards

• IEC 61158 (type-specific parts) - protocol definitions for physical, data‑link and application layers.
• IEC 61784 series - fieldbus communication profiles and functional safety communication profiles.
• ISO/IEC 7498-1 - OSI Basic Reference Model (mapping guidance referenced).
• IEC 61918 - referenced for CPF document structure and installations.

Keywords: IEC 61158-1:2019, fieldbus, industrial communication networks, IEC 61158, IEC 61784, OSI model, application layer, data-link layer, physical layer, CPF, fieldbus data types, industrial control network.