IEC 61158-6-28:2023

Overview

IEC 61158-6-28:2023 is an international standard developed by the International Electrotechnical Commission (IEC) that specifies the application layer protocol for Type 28 elements within industrial communication networks, specifically focusing on fieldbus specifications. Fieldbus systems are essential components in industrial automation for enabling communication between control devices such as sensors, actuators, and controllers.

This part of IEC 61158 targets both time-critical and non-time-critical messaging communications in automation environments. The standard defines the elements required to ensure reliable and timely data exchange, where "time-critical" refers to operations that must be executed within strict time windows to avoid system failures, potential damage to equipment, plant operations, or even risk to human safety.

Key Topics

• Application Layer Protocol Specification: IEC 61158-6-28 focuses on the rules and procedures for peer application entities (AEs) to communicate effectively within automation systems using the Type 28 protocol.

• Time-Critical Messaging: The standard emphasizes handling messages that require guaranteed delivery within defined time constraints, ensuring that automation tasks are executed reliably and safely.

• APDU (Application Protocol Data Unit) Structures: Detailed descriptions of APDU headers and types are provided, covering how data packets are structured for transmission, time services notifications, and system management.

• State Machine Models: Various state machines are defined to represent the behavior of communication entities such as publishers, subscribers, clients, and servers. This formal modeling supports the interpretation and implementation of protocol operations.

• Conformance and Interoperability: Guidelines ensure devices and systems following IEC 61158-6-28 can interoperate within the broader Type 28 fieldbus ecosystem, enabling scalable and modular automation solutions.

• References to Related Standards: The document integrates key concepts and terminologies from related ISO/IEC communications and electromagnetic standards, enhancing alignment across international automation protocols.

Applications

IEC 61158-6-28:2023 is applicable in various industrial and manufacturing settings where reliable and real-time communication between automation components is critical. Typical applications include:

• Process Automation: Coordination of sensors and actuators in chemical plants, oil refineries, and power generation facilities where timing precision is vital.

• Factory Automation: Managing communication between programmable logic controllers (PLCs), motor drives, and robotic systems on production lines requiring synchronized operations.

• Safety-Critical Systems: Deployment in environments where failure to deliver messages within time limits could pose risks to human life or lead to costly equipment damage.

• Material Handling and Logistics: Automation of conveyor systems, warehouse robotics, and inventory management where real-time data exchange optimizes throughput and reduces downtimes.

Implementing IEC 61158-6-28 ensures that automation systems comply with international best practices for fieldbus communication protocols, leading to enhanced system reliability, safety, and maintainability.

Related Standards

This standard is part of the broader IEC 61158 series, which covers industrial communication networks and fieldbus specifications. Related standards and documents include:

• IEC 61158-1: The overall fieldbus reference model defining various protocol layers and general concepts.

• IEC 61784 Series: Provides additional guidelines and profiles for fieldbus systems, including combinations of protocol types standardized for specific industrial applications.

• ISO/IEC 7498-1 and ISO/IEC 9545: Define OSI (Open Systems Interconnection) reference models and presentation layers that underpin communications used by IEC 61158-6-28.

• IEC 61158-5: Covers data-link layer service elements that the application protocol relies on.

• IEC 61784-2: Specifies communication profiles supporting functional safety, often integrated with Type 28 implementations.

Adopting IEC 61158-6-28 along with these related standards facilitates interoperability, compliance with industrial automation regulations, and supports the development of advanced communication architectures in modern manufacturing landscapes.

Keywords: IEC 61158-6-28, industrial communication networks, fieldbus specifications, Type 28 application layer protocol, time-critical messaging, automation communication, industrial automation standards, application protocol data unit, APDU, industrial control systems, fieldbus protocol, IEC standards, automation safety, real-time communication.