OPC Data eXchange (OPC DX) is a specification that defines how OPC servers exchange data with other OPC servers. While a small number of vendors incorporated this specification in their products, there are no commercial implementations of this technology. Instead, corporations are using various forms for OPC bridging products that transfer data between OPC Servers.
The OPC Foundation (www.opcfoundation.org) is responsible for defining and maintaining the OPC DX specification.