IEC 61158-5-4:2019 PDF

Overview

IEC 61158-5-4:2019 - "Industrial communication networks - Fieldbus specifications - Part 5-4: Application layer service definition - Type 4 elements" defines the services and structure of the Fieldbus Application Layer (FAL). It specifies the interface and services at the boundary between the FAL user and the application layer, and between the application layer and Systems Management, in conformance with the OSI Basic Reference Model (ISO/IEC 7498-1) and OSI application layer structure (ISO/IEC 9545). This is the third edition (2019), a technical revision of the 2014 edition, introducing additional user parameters, services to support distributed objects, and additional secure services.

Key Topics

• Application layer service definitions (FAL): Service elements and procedures exposed to application processes and Systems Management.
• Conformance with OSI: Structure follows ISO/IEC 7498-1 and ISO/IEC 9545, ensuring interoperability with OSI-based architectures.
• Application Service Elements (ASEs): Detailed ASE specifications such as Variable ASE, Application Relationship ASE and Route Endpoint ASE, including class specifications and service parameters.
• Service procedures: Confirmed and unconfirmed FAL service procedures and time-sequence diagrams for message exchange.
• Naming, addressing and APDU handling: FAL naming/addressing conventions, object access mechanisms and APDU size considerations.
• Support for distributed objects and security: New services for distributed object management and enhanced secure services added in this edition.
• Management and error handling: Systems Management boundary services, error codes, attribute get/set, and resource reservation/freeing semantics.

Applications

IEC 61158-5-4 is essential for professionals implementing or integrating Fieldbus application-layer components in industrial automation:

• Protocol stack developers building Type 4 fieldbus application-layer implementations.
• Device manufacturers creating fieldbus-capable sensors, actuators and controllers requiring standards-based application services.
• System integrators and network architects designing multi-vendor fieldbus networks and gateways.
• Test and certification labs validating conformance to application-layer service definitions.
• Security and asset managers applying enhanced secure service features and distributed object controls.

Practical benefits include interoperability across devices, consistent application-layer behavior, clearer object and relationship models, and improved support for distributed object architectures and secure communication.

Related standards

• IEC 61158 series (Fieldbus specifications)
• ISO/IEC 7498-1 (OSI Basic Reference Model)
• ISO/IEC 9545 (OSI application layer structure)
• IEC 61784-1 / IEC 61784-2 (protocol-type combinations and profiles)

For implementation or procurement, obtain the full standard and latest corrigenda from the IEC webstore to ensure compliance with the complete normative text.