What is the relationship between DCOM and OPC?
Classic OPC relies on DCOM for data transportation. That is, OPC specifies the format of data that transfers between applications that use OPC. For example, each OPC Data Access application must transfer a timestamp, quality level and data value. It is not enough to simply pass along the data value itself. So while OPC states what information must transfer between applications, DCOM handles the transfer itself. DCOM also handles security aspects such as authentication and encryption.
