IIoT Architecture: Integrating Field Sensor OPC-UA & MQTT with Enterprise Cloud Systems

1. MQTT vs OPC-UA in OT-IT Connectivity

OPC-UA acts as the standard protocol inside the factory floor for machine-to-machine (M2M) communication. MQTT serves as the lightweight transport mechanism to push telemetry over wide area networks (WAN) to AWS IoT Core or Microsoft Azure IoT Hub.

{
  "deviceId": "LINE_01_PUMP_03",
  "timestamp": "2026-08-16T10:30:00Z",
  "telemetry": {
    "vibration_rms_mm_s": 2.45,
    "stator_temp_celsius": 68.2,
    "current_amps": 45.1,
    "power_factor": 0.89
  },
  "status": "HEALTHY"
}