An IIoT-Based Digital Twin Architecture for Remote Supervisory Water-Level Control: Design and Latency Evaluation

Digital twins are attracting growing interest in the industry. They enable the optimization of monitoring, control, and decision-making. However, many existing implementations rely on costly proprietary platforms. This limits their adoption by small and medium-sized enterprises. This paper presents a low-cost digital twin architecture. It is based on open-source platforms (Node-RED, MQTT) and affordable hardware (Raspberry Pi). This architecture was applied to the remote supervisory setpoint control of the water level in an industrial reservoir. Real-time synchronization between the physical system and its digital twin was evaluated through transport-latency measurements on clock-synchronized machines (NTP, inter-clock offset below 0.1 ms), with sequence-numbered messages paired end-to-end between the gateway and the twin. Across several measurement campaigns totaling over 33,000 messages, including a fully paired 5226-message validation session (zero loss, duplication, or reordering), the median transport latency was 44 ms, with 99.20% of messages delivered within 100 ms and occasional peaks of a few hundred milliseconds (maximum 923 ms), consistent with transport-layer retransmission stalls. Despite these peaks, performance remains acceptable for non-critical real-time applications, such as water-level supervisory control, since the resulting estimated level-deviation bound stays within the controller’s 0.2% hysteresis band for 99.0% of messages. These results indicate that a digital twin of a small industrial reservoir can be implemented in a viable and cost-effective manner at the gateway and communication layers. This approach makes the technology more accessible to small and medium-sized industries.