The Internet of Things (IoT) represents the binder of two worlds, specifically the real one and the digital one: tangible objects become recognizable in the virtual world, having digital matches, thus creating a network that enables the connection in-between the components. With the contemporary evolution of this domain, interconnectivity has become a primary fraction of new research and development directions. The Industrial Internet of Things (IIoT) is a concept that covers the more industrial level of the physical and digital connection and stays behind the Industry 4.0 concept. Supervisory control and data acquisition (SCADA) applications are important in the industry, their core being very present as complex products of big companies, at high prices. The Node-RED environment quickly evolved as one of the most important perspectives in IIoT, able to replace, up to a certain level, classic SCADA applications, bringing benefits to the industry. In this paper, the main focus is to evidence this aspect and to develop an application that will demonstrate the functionality of the concept, making use of protocols such as Modbus TCP (Transmission Control Protocol) for interacting with industrial devices and Message Queuing Telemetry Transport (MQTT) to interact with higher-levels, which provides a publish-subscribe structuring and a low band-width usage. The application uses logging and archiving modules based on InfluxDB database and is conceived to achieve the visual supervisory structure as close as possible to well-known SCADA solutions. The presented work results prove the efficiency of the solution.

Considering Industry 4.0 directions, followed by recent Industry 5.0 principles, interest in integrating legacy systems in industrial manufacturing has emerged. Due to the continuous evolution of the Internet of Things (IoT) and the Industrial Internet of Things (IIoT), as well as the rapid extension of the scope and adoption of broader technologies, such integration has become feasible. Even though newly developed equipment provides easier interoperability, the replacement of legacy systems highly impacts cost and sustainability, which usually extends to the entire production process, the operators and the maintenance team, and sometimes even the robustness of the production process. Ensuring the interoperability of legacy systems is a problematic task, being dependent on technologies and development techniques and specific industrial domain particularities. This paper considers strategies to ensure the interoperability of legacy systems in a building-management system scenario where local structures are approached using both industrial protocols and web-based contexts. The solution is built following the Industry 5.0 pillars (sustainability, human focus, resilience) and conceives the entire data acquisition and supervisory solution to be flexible, open-source, resilient, and under the control of company engineers. The chosen environment for interfacing and supervision is Node-RED, enabling IoT and IIoT tools, together with a complete orientation toward digital transformation. This way, it is possible to construct a final result that enhances security while bridging outdated protocols and technologies, eliminating compatibility risks in the context of the evolutionary IIoT, ensuring critical process functions are possible, and aiding operators in complying with regulations governing building-management system (BMS) operations, thus solving the challenges that arise in the complex task of adopting the IoT backbone of digital transformation in relation to the integration of legacy equipment. The obtained solution is tested in an automotive industry building-management system, and the results demonstrate its performance, reliability, and high customizability in a context of openness and low cost.