.NET Realtime Data Access

The .NET Data Connector product provides read and write to realtime tags including data sources of direct drivers to Modbus, Allen Bradley, Siemens, OPC UA Servers, Classic OPC Servers, OPTO-22, MQTT, AWS IoT, Azure IoT Data Hub, Microsoft Excel, data from SQL Server, Oracle, Access, mySQL, MongoDB, REST API, and other .NET applications.

The OASData.dll assembly is a .NET Standard 2.0 assembly which can be integrated into any .NET application with the following targets.

  • .NET 5 or greater
  • .NET Core 2.0 or greater
  • .NET Framework 4.61 or greater
  • Xamarin.iOS 10.14 or greater
  • Xamarin.Android 8.0 or greater
  • UWP or greater

The same access can also be provided in the legacy assemblies for Framework 4.6 or less.
If you are using the OAS WPF HMI product use the OPCWPFDasbhoard.OPCWPFData component.
If you are using the OAS WinForm HMI product use the OPCControls.OPCControlData component.
For .NET Framework 4.6 or less projects without the need for user interface controls use the OPCSystemsDataConnector assembly.

The .NET Data Connector is also a very powerful method to turn any data from a .NET application into a realtime source for the Open Automation Software platform. This is easily done with the WriteTags method which you can optionally specify TimeStamps.

All components have the same easy to use programmatic methods.

The OAS Example Service Code is a working example of reading and writing tags synchronously and asynchronously.  This includes example projects for both C# and VB for .NET Core Console App to run on all operating systems including…

  • Linux
  • Windows
  • Mac
  • Android
  • iOS

There is also C# and VB projects to run as a Windows Service.  The code examples in all 4 projects are the same to show adding tags programmatically and the asynchronous and synchronous methods for reading and writing data.

Applications can be deployed locally or remotely and can optionally implement OAS Basic Networking or Live Data Cloud Networking.

All Tag Variables are accessible for reading and writing.


  • TagName.Value
  • TagName.Desription
  • TagName.Units
  • TagName.HighHighAlarmLimit
  • TagName.HighHighAlarmActive (read only)

See a complete list of Tag Variables


Tag names can include an IP Address, network node name, or registered domain name if the application is deployed remote from the OAS Engine.

Basis Networking Example:


If Live Data Cloud networking is implemented for self-hosting with a dynamic IP Address the LDC syntax is applicable.

Live Data Cloud Networking Example:


Common Methods

See our OASData documentation for more details.

And also Realtime Data Access – VB and C# – Windows Server and .NET Core Console App examples for programmatic tag creation and realtime data access.