Not all WinCC flavors include native REST API support. As of 2025:
| WinCC Version | REST API Support | |----------------------------|--------------------------------| | WinCC Professional (TIA Portal) | ✅ Yes (via WebUX / WebAPI) | | WinCC Advanced (TIA Portal) | ❌ No (limited web services) | | WinCC Classic (V7.x) | ⚠️ Via add-on (Web Service / OData) | | WinCC Open Architecture (OA) | ✅ Built-in REST API | | WinCC Unified (TIA Portal) | ✅ Native REST API (modern) |
For WinCC Classic (V7.5+): You need the "WinCC Web Service" package.
For WinCC Unified: REST API is part of the Unified Web Server – no extra license.
Always verify with Siemens documentation for your exact version and update level. wincc rest api
PUT /WinCC/REST/Tags/TagName
"Value": 80.0
The WinCC REST API is an interesting essay in industrial software evolution: a legacy giant trying to speak the language of the web. It succeeds in lowering the initial barrier to entry for IT developers. It fails to deliver enterprise-grade performance or safety without careful design.
For the bold engineer: use it for monitoring, light control, and integration — but always put a safety PLC between your REST call and any dangerous actuator. For the pragmatic architect: keep OPC UA for core data, and use the REST API where HTTP+JSON genuinely simplifies your life. Not all WinCC flavors include native REST API support
In the end, the most interesting part isn’t the API itself — but what it represents: the slow, painful, and necessary marriage of the factory floor and the internet. And on that journey, every little REST endpoint is a step forward.
Would you like a practical example (e.g., Python code that reads/writes to a WinCC tag via REST) or a deeper comparison with OPC UA?
WinCC OA has its own robust REST API (Control Gateway). It is not identical to the TIA/WinCC Classic APIs. PUT /WinCC/REST/Tags/TagName
Crucial Note: The open-source community has also built unofficial wrappers (e.g., pyWinCC or Node-RED contrib nodes), but this article focuses on the official Siemens REST API available in TIA Portal WinCC Professional.
| Technology | Pros | Cons | |------------|------|------| | WinCC REST API | Simple, HTTP/JSON, language-agnostic, web-friendly | Limited to WinCC Unified/Professional, moderate speed | | OPC UA | High performance, standardized, secure, many SDKs | Steeper learning curve, requires OPC client libraries | | S7 Communication | Lowest latency, direct PLC access | Bypasses WinCC logic & alarming, complex multi-point writes | | WinCC WebUX | Full HMI screen remote access | Heavy, requires WebUX license, not suitable for data integration |
"name": "Pump_Setpoint",
"value": 42.5,
"quality": 192,
"timestamp": "2023-10-27T14:30:05.123Z",
"errorCode": 0,
"errorDescription": ""
Note on Quality Codes: The quality field follows OPC standards. A value of 192 (0xC0) typically means "Good".