The Problem#
OPC-UA is the industry standard for machine-to-machine communication in industrial automation — but existing Node-RED OPC-UA nodes are either too basic (only reading/writing single values) or too complex (requiring deep protocol knowledge). There’s a gap between what OPC-UA can do and what’s accessible in a visual programming environment.
The Solution#
An OPC-UA integration suite for Node-RED that makes the full protocol accessible through intuitive, well-documented nodes — from simple tag reads to complex subscriptions and method calls.
What is OPC-UA?#
OPC Unified Architecture is the interoperability standard for secure, reliable data exchange in industrial automation. It’s platform-independent, vendor-neutral, and supported by virtually every major PLC, SCADA, and MES vendor.
┌──────────┐ ┌──────────┐ ┌──────────┐
│ Siemens │ │ Beckhoff │ │ ABB │
│ PLC │ │ PLC │ │ DCS │
└────┬─────┘ └────┬─────┘ └────┬─────┘
│ │ │
└──────┬──────┴─────────────┘
│ OPC-UA
┌──────┴──────┐
│ Node-RED │──→ Dashboard
│ OPC-UA │──→ Database
│ Suite │──→ Cloud/MQTT
└─────────────┘Why OPC-UA?#
| Feature | Modbus | MQTT | OPC-UA |
|---|---|---|---|
| Data typing | No | No | Yes (rich types) |
| Information model | No | No | Yes (browsable) |
| Security | None | TLS | TLS + certificates + auth |
| Discovery | No | No | Yes (automatic) |
| Method calls | No | No | Yes |
| Historical data | No | No | Yes (built-in) |
| Industry adoption | Legacy | IT/IoT | OT/Automation |
Use Cases#
- Multi-vendor data collection — Read data from Siemens, Beckhoff, Allen-Bradley, and others through one protocol
- Shopfloor to Cloud — Bridge OPC-UA data to MQTT, NATS, or REST APIs for cloud analytics
- Recipe Management — Write setpoints and parameters back to PLCs
- Alarming — Subscribe to OPC-UA alarms and conditions for real-time notifications
