Overview
IEC 61158-5-28:2023 is an international standard published by the IEC focusing on industrial communication networks, specifically fieldbus specifications for application layer service definition using Type 28 elements. This standard addresses the requirements for both time-critical and non-time-critical messaging communications between application programs in automation environments.
The application layer described by this standard serves as a “window” between user programs and the fieldbus communication infrastructure, enabling effective communication and interoperability in industrial automation systems. Type 28 elements define specific services for ensuring timely exchanges, resource management, network management, and information consistency, which are critical in the context of process control, manufacturing, and factory automation.
Key Topics
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Time-Critical and Non-Time-Critical Messaging
IEC 61158-5-28 provides descriptions for messaging communications that must be performed within precise time windows to ensure determinism, as well as support for messages that do not have time constraints, making it suitable for diverse industrial scenarios.
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Fieldbus Application Layer Services
The standard details the architecture and operation of the Fieldbus Application Layer (FAL), including the use of Application Service Elements (ASEs), which provide structured, object-oriented access to resources and data.
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Application Service Elements (ASEs)
Several ASEs are defined, like those for real-time data (RT Data), non-real-time data (nRT Data), time synchronization, resource management, addressing, management, and virtualization. Each enables modular and scalable service delivery within industrial networks.
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Abstract Service Definition
Services are defined abstractly-focusing on externally visible operations, events, and parameters-without dictating implementation, allowing for flexibility and compatibility with a range of protocols and technologies.
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Conformance and Interoperability
While not prescribing product implementations, the standard guides the development of application layer protocols and migration from legacy protocols to modern fieldbus communication systems.
Applications
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Industrial Automation and Process Control
The standard is essential in environments where precise, reliable, and timely data exchange is mandatory, such as in automated manufacturing lines, distributed control systems (DCS), and programmable logic controllers (PLC).
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Network and Systems Management
IEC 61158-5-28 enables automated systems management, including network resource allocation, configuration, and diagnostics-crucial for maintaining system health and reducing downtime.
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Flexible Integration
Its support for both real-time and non-real-time messaging allows integration with diverse industrial devices, sensors, and controllers, while abstract service definitions facilitate interoperability among different vendors.
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Migration to Modern Protocols
By offering a structured service framework, the standard provides a roadmap for organizations transitioning from legacy communication systems to advanced fieldbus protocols.
Related Standards
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IEC 61158 Series: The complete suite of fieldbus specifications, including data-link and application layer details.
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IEC 61784 Series: Defines communication profiles using fieldbuses, supporting selection and implementation in industrial environments.
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ISO/IEC 7498-1: OSI Basic Reference Model, foundational for structuring communications in networked systems.
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ISO/IEC/IEEE 8802-3: Ethernet standard, relevant for physical and data-link layer considerations in industrial networks.
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IETF RFC 791 / RFC 2460: Internet Protocol (IP) standards, supporting network interoperability.
Practical Value
Implementing IEC 61158-5-28:2023 enables manufacturers and automation engineers to:
- Build interoperable industrial networks with consistent and reliable data exchange.
- Support scalable solutions for both time-critical and routine communication needs.
- Enhance automation system flexibility and lifecycle through standardized interfaces.
- Reduce costs and complexity associated with integrating devices from multiple vendors.
This standard is vital for anyone tasked with designing, deploying, or maintaining modern, robust industrial communication networks using fieldbus systems.