What is OPC Classic?

The OPC Classic specifications are based on Microsoft Windows technology, using COM/DCOM (Distributed Component Object Model) for communication among software components in a distributed client-server network. The OPC Classic specifications provide separate specifications for exchanging process data, alarms and historical data.

The original OPC Classic specification is OPC DA (Data Access), which defines an interface between client and server applications to exchange process and manufacturing data. Other important OPC Classic specifications include OPC Alarms & Events (OPC AE) and OPC Historical Data Access (OPC HDA).

OPC Classic continues to be an integral part of the OPC technology portfolio. In 2010, OPC Classic was enhanced with the OPC .NET 4.0 specifications to adapt to the new technical innovations of the Microsoft platforms providing better connectivity, reliability, security and interoperability.