IEC 61158-5-25:2019

Overview

IEC 61158-5-25:2019 is part of the IEC 61158 series, providing specifications for industrial communication networks, specifically fieldbus systems. This standard focuses on the application layer service definition for Type 25 elements, detailing the structure and services of the fieldbus Application Layer (FAL) in alignment with the OSI Basic Reference Model (ISO/IEC 7498-1) and OSI Application Layer Structure (ISO/IEC 9545).

The standard defines how the FAL acts as an interface-essentially a "window"-between industrial automation system application programs, supporting both time-critical and non-time-critical communications within fieldbus networks. It provides a common framework to facilitate interoperability and reliable communication between automation devices and systems.

Key Topics

• Application Layer Services: The standard specifies abstract service definitions for the fieldbus application layer, supporting reliable data exchange between application entities (AEs).
• Object-Oriented Structure: The FAL AE framework consists of Application Service Elements (ASEs) and a Layer Management Entity (LME), providing object-oriented services and management features.
• Model Conformance: All definitions align with major international standards, specifically ISO/IEC 7498-1 and ISO/IEC 9545.
• Cyclic and Acyclic Communications: Support for both periodic (cyclic) and on-demand (acyclic) communication is included for real-time and non-real-time data transfer needs.
• Service Primitives: Detailed definitions for the primitive actions, parameters, and valid interaction sequences between application programs and the fieldbus network.

Applications

IEC 61158-5-25:2019 is essential for developers, integrators, and users of industrial automation systems that implement fieldbus networks, specifically those utilizing Type 25 elements. Practical applications include:

• Interoperability: Ensures that automation devices from different vendors can communicate reliably at the application layer.
• Process Automation: Facilitates integration of sensors, actuators, controllers, and other field devices in process industries such as manufacturing, power generation, and chemical processing.
• System Management: Provides standardized services for monitoring and managing the behavior and configuration of automation network devices.
• Migration Support: Assists in transitioning from legacy industrial communication protocols to standardized fieldbus solutions.
• Time-critical Operations: Supports applications where the timely exchange of information is crucial for safety and process control.

Related Standards

IEC 61158-5-25:2019 functions within a larger family of standards for industrial communication networks. Key related standards include:

• IEC 61158-3-25: Data-link layer service definitions for Type 25, foundational for the operation of the application layer.
• IEC 61158-6-25: Application layer protocol specification for Type 25, specifying the protocols that implement the services.
• IEC 61158-1: Overview of fieldbus reference models and three-layer architecture used throughout the standard series.
• IEC 61784 Series: Profiles for communication networks in industrial environments, providing guidance on the practical implementation of fieldbus standards.
• ISO/IEC 7498-1: OSI Basic Reference Model, the underlying model for organizing network layers and services.
• ISO/IEC 9545: Application Layer Structure, detailing the organization and function of the application layer in open systems interconnection.

By utilizing IEC 61158-5-25:2019, organizations can enhance the reliability, safety, and interoperability of their industrial automation networks, ensuring robust solutions for modern manufacturing and process control systems.