Session: 02-05-01: IoT and Digital Twins

Paper Number: 167395

MQTT-UNS and OPC UA in RAMI4.0: A Comparative Analysis for Industrial Communication 

In the era of Industry 4.0, achieving seamless data integration and interoperability across diverse systems is fundamental to driving digital transformation in manufacturing. The Reference Architecture Model for Industry 4.0 (RAMI 4.0) serves as a structured framework designed to address these challenges by encompassing lifecycle phases, functional layers, and system hierarchies.

This study focuses on the implementation of Open Platform Communications Unified Architecture (OPC UA) and Message Queuing Telemetry Transport (MQTT) with Unified Namespace (UNS) within the RAMI 4.0 framework. Through an analysis of technical literature and relevant research, the study examines the effectiveness of MQTT-UNS for the communication and information layers of RAMI 4.0, particularly in comparison to OPC UA.

The primary objective of this research is to bridge existing gaps by conducting a comparative analysis of these two communication protocols. The key scientific contribution of this study lies in evaluating whether the integration of UNS with MQTT enhances its capabilities to the extent that it becomes a viable communication solution within the RAMI 4.0 architecture.

Interoperability is one of the most significant challenges in Industry 4.0, as different communication protocols are designed for various system architectures. Choosing an appropriate solution is critical for ensuring smooth integration and efficient data exchange across manufacturing environments. RAMI 4.0, widely regarded as a leading reference architecture, recommends OPC UA as the preferred protocol, particularly for the information layer, as it provides a standardized approach to data exchange and system interaction. Meanwhile, MQTT has gained traction due to its lightweight nature and suitability for Industrial Internet of Things (IIoT) applications. When combined with UNS, MQTT has the potential to structure and manage data more effectively, but its role within RAMI 4.0, especially within the communication layer, remains ambiguous.

To address this gap, this study conducts a technical comparison between MQTT-UNS and OPC UA, analyzing their capabilities, advantages, and limitations within the RAMI 4.0 framework. Preliminary findings suggest that MQTT fulfills the essential technical requirements of the communication layer. Furthermore, UNS provides a structured data framework, enabling MQTT to function as a robust solution not only for the communication layer but also for the information layer of RAMI 4.0.

Globally, this research contributes to the ongoing discourse on interoperability in Industry 4.0 by evaluating the feasibility of using MQTT-UNS as an alternative or complementary communication strategy alongside OPC UA. The findings could inform manufacturing enterprises, system integrators, and industry stakeholders in their decision-making processes regarding protocol selection for digital transformation initiatives within RAMI 4.0-based architectures. By enhancing understanding of these technologies, this study aims to support the development of more interconnected, efficient, and scalable industrial systems in the Industry 4.0 landscape.

Presenting Author: José Machado University of Minho

Presenting Author Biography: José Machado concluded Habilitation Title in February 2019 at University of Minho, Portugal. He received his PhD degree in Mechanical Engineering – Automation, from University of Minho, Portugal and, in simultaneous, from Ecole Normale Superieure de Cachan, France, in 2006. He is Deputy Director of MEtRICs Research Center and Associate Professor w/ Habilitation at Mechanical Engineering Department of University of Minho. He has authored, or co-authored, more than 250 refereed journal and conference proceedings papers. He coordinates and has coordinated - and participated as collaborator - in several Research and Technology Transfer Projects on Mechatronics and Automation domains. His main interests are related with Industry 4.0, more specifically, on the design and development of Cyber-Physical Systems; design and analysis of dependable controllers for obtaining dependable mechatronic systems; and mechatronic systems design with special focus on manufacturing industry and medical or biomedical applications, wellbeing and/or rehabilitation. He is member of Scientific Communities IEEE, IFAC and IFToMM.

Authors:

Luís Freitas University of Minho
Filipe Pereira University of Minho
Helena Lopes University of Minho
Camelia Avram Technical University of Cluj-Napoca
Nuno Leal Sonae Arauco Portugal, S.A.
José Machado University of Minho