Suppose you’re tired of combining scripts and middleware to get live values from your control systems into a dashboard or analytics tool. In that case, the OPC Expert REST API Server is the streamlined solution you’ve been waiting for. Whether building an HTML5 dashboard, integrating alarms in a SCADA-lite setup, or feeding values into a Python-based analytics engine, the REST API gives you up-to-the-second access to data, directly from your OPC servers.
Let’s break down what this means in practice—and how simple it is to get started.
From Setup to Streaming in Minutes
Activating the REST API server is refreshingly straightforward. From the OPC Expert GUI, navigate to:
Tools → Servers & Services,
Then check the boxes for both “OPC Expert UA server” and “REST API server”,
and click OK.
You’ll see the services start up immediately under the System account. Behind the scenes, the other PC Expert sets everything up as Windows services—no command-line tinkering required.
Browse & Trend Data Instantly
Once your REST API server runs, you can browse available data sources (DA, UA, Modbus, MQTT, etc.) directly in OPC Expert. You’ll see servers like:
- ICONICS.Simulator.OPCDA.2
- opc.tcp:// endpoints
To validate your setup, right-click a data point and select Trend. OPC Expert’s built-in trend viewer uses the REST API, so if you see a real-time graph, you know the API is working.
Use Real-Time Data Anywhere—Desktop, Web, or Mobile
Once trending is active, the REST API’s flexibility becomes clear. The same data trend you see in the desktop app can be:
- Opened in a local browser (Options → Open on local browser)
- Accessed on a mobile device using a QR code
- Embedded into an HMI dashboard or third-party system
The browser-based trend UI is shown below, as well as the mobile QR flow.
Need access from your phone or tablet while walking the floor? Scan the QR code and go.
Pull Real-Time Values from Python, JavaScript, and More
Thanks to automatic source code generation, OPC Expert provides ready-to-go code snippets in Python, JavaScript, C#, and other languages. Right-click on a tag, and the command is instantly copied to your clipboard—there is no need to wrestle with syntax or authentication headers.
For example, generating a Python command to read a Numeric. Random value takes just two clicks:
- Right-click the item
- Select REST API Command → Generate Code Snippet → Read → Python
Paste it into your IDE, run the script, and you’re pulling live data.
Why It Matters: Real Use Cases
Dashboards: Feed JSON values into Grafana, Power BI, or custom visualizations
Alarms: Set thresholds in your scripts and get notified when data crosses limits
Analytics: Stream data into Python, R, or MATLAB for deeper operational insights
Mobile Access: Operators can check KPIs or live values on their phones, without complex VPN setups
Reduced Downtime: Immediate data means quicker diagnostics, faster fixes
Summary: Simplified, Secure, and Scalable
The OPC Expert REST API Server removes the complexity of accessing live control system data. With cross-platform access, JSON output, and broad language support, it’s ideal for system integrators, developers, and operations teams.
Whether you’re embedding data in dashboards or scripting live analytics, you now have an easy way to connect your OPC systems to the tools that make decisions happen.