OPC Studio User's Guide and Reference
Reactive Programming Model
The reactive programming development model merges the world of Microsoft Reactive Extensions (Rx) for .NET with OPC. The Reactive Extensions (http://msdn.microsoft.com/en-us/data/gg577609.aspx) is a library to compose asynchronous and event-based programs using observable collections (data streams) and LINQ-style query operators.
OPC Data Client provides OPC-specific classes that implement the Rx interfaces. For example, you can easily create an Rx observable sequence with OPC-DA. OPC XML-DA or OPC-UA item changes, and process it further. Similarly, you can create an Rx observable sequence with OPC-A&E event notifications.
For complex event and stream processing that builds on top of the reactive programming model, see also