Wincc Rest Api May 2026

By default, browsers restrict web apps from making requests to a different domain/port than the one they served from. The WinCC REST API server must be configured to allow CORS headers if you are hosting a frontend dashboard on a different server that queries WinCC directly.

WinCC OA has its own robust REST API (Control Gateway). It is not identical to the TIA/WinCC Classic APIs.

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.

curl -X GET "https://192.168.1.100/api/v1/tags/Tank1_Level" \
     -H "Authorization: Bearer <your-token>"

Response:

  "name": "Tank1_Level",
  "value": 74.3,
  "quality": "good",
  "timestamp": "2025-03-15T14:22:10Z"

The WinCC REST API bridges the classic SCADA world with modern web and cloud ecosystems. It’s not the right tool for every job (stay away from high-speed control loops), but for dashboards, reporting, ERP integration, and remote monitoring, it’s a game-changer.

Your next steps:

The era of locked-in SCADA data is ending. With REST APIs, your WinCC system becomes a first-class citizen in the connected enterprise. wincc rest api

Have you implemented WinCC REST API in a real project? What challenges did you face? Share your experience in the comments below!

The WinCC REST API (Representational State Transfer Application Programming Interface) is a modern, flexible interface introduced to bridge the gap between traditional industrial automation (OT) and standard IT systems. It allows external applications to interact with Siemens SIMATIC WinCC using standard HTTP methods and JSON data formats.  Key Components of WinCC REST Functionality 

Siemens offers two distinct ways to use REST with WinCC, depending on whether WinCC is the "server" or the "client": 

REST API (Server Role): Introduced in WinCC V7.5 SP2 and enhanced in WinCC V8.0, this acts as a passive interface. External applications (like AI agents, ERP systems, or custom web dashboards) can "pull" data from WinCC or "push" values to it.

REST Connector (Client Role): This allows WinCC to act as a client that "actively" sends requests to other systems (e.g., sending an alarm notification to a messaging service or updating a cloud database).  Core Capabilities 

The REST interface provides access to three primary types of WinCC data:  By default, browsers restrict web apps from making

Tags (Runtime Values): Read and write process values in real-time.

TagLogging (Historical Data): Access archived process data for trend analysis or reporting.

AlarmLogging (Alarms & Messages): Query active alarms or historical alarm logs to track system events.  Implementation and Security 

Standard Methods: It uses common HTTP verbs: GET to retrieve data, POST to create or trigger actions, and PUT to update tag values.

Configuration: A built-in JSON configurator helps users define endpoints and trigger methods based on specific tags or alarms.

Security: Security modes can be configured separately for each server, typically utilizing encryption and secure port binding to protect sensitive industrial data.  Common Use Cases  WinCC OA has its own robust REST API (Control Gateway)

AI and Machine Learning: Exporting historical data to Python libraries for predictive maintenance or anomaly detection.

IT/OT Integration: Connecting SCADA data directly to enterprise resource planning (ERP) or manufacturing execution systems (MES) without complex middleware.

Custom Web Dashboards: Building lightweight, platform-independent monitoring tools that run in any standard web browser. 

For official technical documentation and specific implementation steps, users often refer to the Siemens Industry Online Support portal. 

curl -X POST https://192.168.1.100:5001/api/v1/auth/login \
  -H "Content-Type: application/json" \
  -d '"username":"operator","password":"secret"' \
  -k   # ignore self-signed certificate for testing

Response:

"token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..."

| 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 |