Wincc Rest Api Patched May 2026
Here’s a short, insightful essay on the WinCC REST API — exploring its significance, technical reality, and the hidden challenges behind “modernizing” industrial HMI/SCADA systems.
Practical REST API Examples
Let’s walk through common operations using curl (command line) and Python.
For WinCC Professional (TIA Portal)
- Similar steps, but REST API support may be more limited (mostly tag read/write). WinCC Unified is the recommended platform for REST API usage.
9. Conclusion
The WinCC REST API is a critical enabler for the digitization of manufacturing. By exposing SCADA functionality via standard HTTP/JSON endpoints, Siemens has lowered the barrier to entry for IT developers looking to consume OT data.
It is best utilized for vertical integration (sending data to ERPs, Cloud, or Dashboards) and mobile solutions. For high-performance horizontal communication (PLC-to-PLC or local HMI-to-PLC), OPC UA remains the recommended standard. Integrators should pay close attention to security configuration (SSL certificates and User Mapping) to ensure that opening the REST API does not create vulnerabilities in the industrial network.
The WinCC REST API is a self-hosted service available in SIMATIC WinCC (V7.5 SP2 or higher) and WinCC Unified that enables external applications to securely interact with SCADA Runtime and configuration data using standard HTTP methods and JSON. Core Capabilities wincc rest api
The API serves as a bridge between the industrial OT layer and IT applications, allowing for:
Data Access: Read and write both Runtime values (tags) and configuration data.
System Integration: Connect external tools like C# applications or reporting platforms (e.g., Power BI) to WinCC.
Cloud Connectivity: Send data to cloud platforms via the WinCC/Cloud Connector using the REST protocol. Bi-directional Communication: Here’s a short, insightful essay on the WinCC
REST Service (Inbound): External apps call WinCC to request or update data.
REST Connector (Outbound): WinCC actively sends data to external REST interfaces, such as weather services. Standard Methods Supported The interface follows standard RESTful principles: GET: Retrieve tag values or project configuration.
POST: Send multiple values or specific resources in the request body.
PUT: Update individual values, often used for cloud synchronization. Setup and Security REST Reporting API - WinCC OA Practical REST API Examples Let’s walk through common
3. WinCC Classic (V7.x)
The classic WinCC (V7) traditionally lacked a native REST API. However, users often bridge this gap using:
- DataMonitor (Web-based trending and reporting).
- WebUX (Limited in older versions).
- Custom Middleware (A small C# or Python application that reads OPC DA/UA and exposes a REST endpoint).
For this article, the primary focus will be on WinCC OA and WinCC Professional (TIA Portal V17+) , as they represent the future.
Limitations and Considerations
Before you go all-in, understand the constraints:
- Performance: REST is not designed for millisecond-level polling. For high-speed data (e.g., 100 ms updates), use OPC UA Pub/Sub or a native driver.
- Concurrent connections: WinCC Web server has a limit (typically 5–10 simultaneous REST clients, depending on license).
- Write operations: Some tag types (e.g., internal system tags) may be read-only via API.
- No browsing (limited): Most versions don’t offer full tag tree browsing. You need to know tag names in advance.
- Stateless: Each request is independent. For streaming, consider WebSockets (available in WinCC Unified separately).