Industrial IoT Glossary — 30+ IIoT Terms Explained

A software system that enables remote monitoring and control of industrial facilities. SCADA collects field data (from sensors and PLCs), displays it on process diagrams, and enables commands to be sent. Examples include monitoring a water treatment plant, a power grid, or a production line.

Application of IoT technologies (connected sensors, communication protocols, cloud) to industrial environments. The IIoT connects machines, PLCs, and sensors to cloud-based monitoring platforms to improve maintenance, efficiency, and traceability. It differs from consumer IoT in its requirements for reliability, security, and robustness.

A set of techniques used to remotely monitor and control equipment or facilities via a communications network (4G, fiber, satellite). Remote management includes remote control (sending commands), remote measurement (collecting data), and remote signaling (receiving alarms).

The ability to diagnose and service industrial equipment remotely, without the need for on-site visits. Remote maintenance reduces downtime and travel costs. It relies on secure remote access to programmable logic controllers (PLCs), HMI interfaces, and SCADA systems via an industrial VPN.

Automated and remote collection of meter readings (water, gas, electricity, heat) via a communication network. Remote meter reading replaces manual meter readings, improves billing accuracy, and enables real-time detection of consumption anomalies.

A maintenance strategy based on the continuous analysis of operational data to predict failures before they occur. It relies on machine learning algorithms applied to sensor data (vibration, temperature, current, pressure) to detect early anomalies.

An industrial communication protocol created by Modicon in 1979. Modbus RTU (Remote Terminal Unit) uses an RS-485 or RS-232 serial connection. Each slave has a unique address (1–247). The master sends requests, and the slaves respond. Ideal for short distances (up to 1,200 m on RS-485) with a small number of devices (up to 32 on a single bus).

A variant of the Modbus protocol that operates over TCP/IP via Ethernet or Wi-Fi. It allows for unlimited distances (via an Ethernet network or the Internet using a VPN), a more flexible topology, and transmission speeds significantly higher than those of Modbus RTU. The standard port is 502. Widely adopted by new industrial equipment.

A publish/subscribe messaging protocol designed for low-bandwidth, high-latency networks. A broker (Mosquitto, AWS IoT, Azure IoT Hub) manages messages between publishers and subscribers. MQTT has become the dominant industrial IoT protocol for transmitting sensor data to the cloud. Standard port: 1883 (unencrypted) or 8883 (TLS).

A platform-independent industrial communication standard created by the OPC Foundation (IEC 62541). OPC-UA defines not only a transport protocol but also a semantic data model. It is the industry standard for IT/OT integration and Industry 4.0. Compatible with Siemens S7-1500 PLCs, Beckhoff PLCs, and most modern SCADA systems.

An industrial communication protocol used primarily in the water and energy (utilities) sectors. DNP3 is designed for challenging environments with unreliable communications (radio and satellite links). It natively supports timestamping, data integrity, and event prioritization. IEEE 1815 standard.

A physical serial communication standard that enables long-distance transmissions (up to 1,200 meters) with up to 32 devices on a single bus. RS-485 is the physical layer used by Modbus RTU. The differential connection makes it resistant to electromagnetic interference, which is crucial in industrial environments (drives, motors).

An industrial computer designed to automate electromechanical processes. A PLC runs a cyclic program (typical scan time: 1–100 ms) that reads inputs (sensors, buttons), executes logic, and controls outputs (actuators, motors). The leading manufacturers are Siemens (S7), Schneider (M340, M580), Rockwell (Allen-Bradley), Beckhoff, and Wago.

An electronic device designed to transmit field data to a central SCADA system. RTUs are optimized for long-distance communications (GPRS, radio, satellite) in wide-area networks (water, power, pipelines). Although less powerful than PLCs for local automation, they excel at monitoring remote sites with limited bandwidth.

Electronic equipment that bridges the gap between industrial devices (using Modbus, PROFIBUS, CAN) and modern IP networks (Ethernet, Wi-Fi, 4G). The IIoT gateway collects data from sensors and PLCs, converts it into cloud protocols (MQTT, HTTP/REST), and transmits it to the monitoring platform.

Router designed for industrial environments: extended temperature range (-40°C to +70°C), 9–48 V DC power supply, DIN rail enclosure, MTBF > 10 years, CE/E-Mark/ATEX certifications. Unlike consumer routers, these support M2M SIM cards, industrial VPNs (OpenVPN, IPsec), ZTP remote management, and RS-485/232 serial protocols.

An industrial router feature that allows the simultaneous use of two SIM cards from two different carriers. If network connectivity is lost with Carrier 1, the system automatically switches to Carrier 2 (failover). This redundancy increases network availability from 99.5% (single SIM) to 99.99% (Dual SIM). Essential for mission-critical applications.

A computing paradigm in which data processing takes place at the device that collects it (the “edge” of the network), rather than sending everything to a central cloud. In industry, edge computing enables real-time decision-making (< 1 ms), reduces bandwidth consumption, and ensures continued operation even without an internet connection.

A proven open-source VPN protocol based on the TLS/SSL stack, AES-256-GCM encryption, and mutual authentication using X.509 certificates. Its major advantage in industrial applications is that it can run over TCP on port 443 (like HTTPS), allowing it to pass through mobile operators’ firewalls and NATs. OpenVPN is the industry standard for industrial VPNs.

A security architecture based on the "never trust, always verify" principle. Unlike traditional VPNs, which grant broad network access, ZTNA enforces granular access controls: each user is granted access only to the resources they need, with continuous verification of identity and context.

European Directive (EU 2022/2555) strengthening cybersecurity for operators of essential services. Transposed into French law in 2024–2025, NIS2 applies to the energy, water, healthcare, transportation, and digital sectors. It mandates technical measures (strong authentication, encryption, traceability of operational technology access), incident reporting requirements (24 hours/72 hours), and penalties of up to €10 million.

OT refers to IT systems that directly control physical processes (PLCs, SCADA, sensors). IT refers to traditional information systems (ERP, CRM, email). IT/OT convergence (Industry 4.0) connects these two worlds, creating opportunities but also new cybersecurity risks for OT networks that have historically been isolated.

A set of international standards defining cybersecurity requirements for industrial control systems (ICS). IEC 62443 covers the entire lifecycle (design, deployment, operation) and defines security levels (SL 1 through 4). It serves as the complementary technical reference to NIS2 for operators of critical infrastructure (OCI).

A process that automatically configures network equipment when it is first powered on, without human intervention. The equipment contacts a cloud provisioning server, downloads its configuration, and activates itself. ZTP is essential for deploying fleets of industrial routers across hundreds of sites without sending a technician to each site.