OPC dynamic data make their way to Excel using a built-in Excel function (RTD) that you can use in any cell. RTD is Microsoft's preferred way to get real-time data into Excel, instead of the obsolete DDE. It is possible to type in the RTD function manually as with any other function, but it is by far easier to select the OPC data in Connectivity Explorer tool, and drag-and-drop (or copy&paste) them to Excel. The RTD function addresses a so-called Connectivity RTD Server, a COM component that is part of the Excel Option, and this RTD server then performs the necessary communication with the data source.

In design-time, you would therefore typically use the Connectivity Explorer to locate the dynamic data and transfer them to the Excel worksheets you are creating, or you would type in the formulas containing the RTD functions directly into Excel.

In run-time, only the Connectivity RTD Server has to be installed on the computer, for your Excel worksheets to be functional.