Why Use an OPC XML-DA Server Simulator?

OPC XML-DA is one of the older technologies in the OPC Classic family for exchanging data through web services. As more modern technologies such as OPC UA are now widely used, ready-to-use OPC XML-DA Server applications suitable for development environments may be more difficult to find compared with other OPC technologies.

However, connecting to a real XML-DA Server may still be necessary when maintaining existing systems, redeveloping legacy applications, testing different OPC clients, or developing a new OPC XML-DA Client. OpenXmlDaServer was developed to provide a simple and practical solution for this requirement in a development environment.

Primary purpose: OpenXmlDaServer is not a field simulation system. It is primarily designed to provide an OPC XML-DA Server source for software development, integration, and testing.

Key Features

  • OPC XML-DA Server: Provides a server simulation that OPC XML-DA clients can connect to.
  • Wind turbine data model: Presents process data from a typical wind turbine in a hierarchical structure.
  • Random data generation: Measurement values are simulated without requiring a real field device.
  • Client development support: Facilitates testing of connection and data reading functions in newly developed OPC XML-DA Client applications.
  • SCADA development: Can be used to develop SCADA and data acquisition applications that use an OPC XML-DA data source.
  • Local operation: Can be run on a development computer through localhost.
  • No external field system required: Testing does not require a real OPC XML-DA Server or a physical wind turbine connection.

Wind Turbine Data Hierarchy

OpenXmlDaServer presents data within a defined hierarchy so that client applications can be tested as if they were working with a real industrial data source. The hierarchical structure helps test tag discovery, addressing, data selection, and value reading operations.

Example data model:

  • WindTurbine
    • Electrical – electrical measurements
    • Mechanical – mechanical operating values
    • Environment – environmental measurements
    • Status – turbine operating and status information

This structure is an example model. The actual tag names and hierarchy provided by the simulator should be evaluated according to the version of OpenXmlDaServer.exe being used.

Before Running

OpenXmlDaServer provides its OPC XML-DA service through port 8080. Therefore, no other application or service using the same port should be running. This should be checked before starting the server.

Important: If another service is using port 8080 on your computer, that service must be stopped before starting OpenXmlDaServer. Otherwise, OpenXmlDaServer may be unable to bind to port 8080 and may not be able to provide the OPC XML-DA service.

In addition, OpenXmlDaServer.exe must be run as Administrator. In Windows, right-click the application file and select Run as administrator.

Startup sequence:

  1. Check whether another service or application is using port 8080.
  2. If so, stop the service using port 8080.
  3. Right-click OpenXmlDaServer.exe.
  4. Select Run as administrator.
  5. After the server starts, launch your OPC XML-DA Client application and test the connection.

After these preparations, the OPC XML-DA Client application can connect to OpenXmlDaServer through the following endpoint:

http://localhost:8080/XmlDa/

Usage

  1. Download OpenXmlDaServer.exe to your development computer.
  2. Run the application. The server simulator will start providing the OPC XML-DA service on the local computer.
  3. Connect to the server from your OPC XML-DA Client application.
  4. Use the following endpoint as the connection address:

    http://localhost:8080/XmlDa/

  5. Use your Client application to read the provided data hierarchy and tag values, and test connection and data processing functions.

Note: localhost should only be used when OpenXmlDaServer and the OPC XML-DA Client are running on the same computer. If the server is running on another computer, replace localhost in the connection address with the server computer's IP address or an appropriate host name.

Use Cases in Software Development

Use Case Topics That Can Be Tested with OpenXmlDaServer
OPC XML-DA Client Connection, tag access, data reading, and error handling.
SCADA Retrieving and processing process values from an OPC XML-DA data source.
Data Acquisition Periodic reading of tag values and transferring them to different data structures.
Protocol Integration Testing OPC XML-DA together with other communication or data processing layers.
Debugging Investigating Client connection problems and XML-DA request/response operations in a development environment.

OPC XML-DA Connection Address

OpenXmlDaServer is designed to be used by default on the local computer through the following endpoint:

Server Endpoint

http://localhost:8080/XmlDa/

You can access OpenXmlDaServer by using this address in the connection settings of your OPC XML-DA Client application.

Download OpenXmlDaServer

OpenXmlDaServer is provided for the development and testing of OPC XML-DA Clients and similar industrial software applications.

⬇ Download OpenXmlDaServer

Execution requirements: Before running OpenXmlDaServer.exe, make sure that port 8080 is not being used by another service. The application must also be started using Run as administrator.

Note for developers: The primary purpose of the simulator is not to be used as an OPC XML-DA Server in a production environment, but to provide a controlled data source for software development, integration, and testing processes.

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