Which of the following is primarily a platform-independent communications protocol used for data exchange in industrial automation?

• A. Modbus RTU
• B. CAN bus
• C. OPC UA
• D. I2C

Answer: (C)

Platform-independent data exchange in industrial automation is achieved by a framework that decouples data representation from transport. OPC UA is built as a vendor-neutral, platform-independent architecture that provides a service-oriented interface and a rich information model, allowing data, events, and historical information to be shared across devices, controllers, and enterprise systems regardless of hardware or software. It runs on multiple platforms—from embedded controllers to enterprise servers—and supports various transport mechanisms and strong security, enabling true interoperability across different vendors and system layers. Other options serve different purposes: Modbus RTU is a simple serial protocol, CAN bus is a fieldbus for real-time device networks, and I2C is a short-range inter-chip bus. They don’t offer the same cross-platform data modeling and enterprise-level interoperability that OPC UA delivers, so OPC UA is the best fit.