RSLinx OPC server

I am using RSLogix 500, RSLinx Gateway 2.43, and RSlogix Emulate 500 for inhouse testing. I need to set up an OPC connection in RSLinx so that I can use Proficy iHistorian/RSLinx OPC Server connection to collect data. If I create a topic under the DDE/OPC menu item and use Cimplicity Plant Edition and its OPC Client to connect to my RSLogix project, the connection shows up in RSLinx as a DDE connection. The RSLinx Online Help is not very helpful.
Anyone know?

"shows up in RSLinx as a DDE connection." Where, precisely, do you see this indication ?

It's probably just an artifact of labeling. RSLinx Classic configures and manages DDE and OPC topics just the same.

If you connected from an OPC Client, be assured that you are making an OPC connection.

You can probably see the same label by connecting using the RSI OPC Test Client.