The OPC Data Access Specification is the first of a group of specifications known as the Classic OPC Specifications maintained by the OPC Foundation and deals only with real-time data. OPC DA is based on OLE (Object Linking and Embedding), COM, and DCOM Microsoft's proprietary technologies. Use this tag for questions on OPC DA part of the OPC Classic specification. For OPC UA, use the tag [opc-ua]. For OPC HDA and OPC AE, use the [opc] tag.
