OPC (OLE for Process Control. OLE = Object Linking Embedding) is an industry standard for interoperability of process control software, using Microsoft COM as middleware. The OPC members are mainly automation companies i.e. Fisher Rosemount etc. OPC addresses a different and complementary subject. CO makes use of OPC interfaces for accessing the process control data. OPC does not address interoperability of process models – this is where CAPE-OPEN interfaces are used.