NAPOPC_ST DA Server free OPC DA Server (The "OPC" stands for "OLE for Process Control" and the "DA" stands for " Data Access") provided by ICP DAS. The first standard (originally called simply the OPC Specification and now called the Data Access Specification) resulted from the collaboration of a number of leading worldwide automation suppliers working in cooperation with Microsoft. Originally based on Microsoft's OLE COM (component object model) and DCOM (distributed component object model) technologies, the specification defines a standard set of objects, interfaces and methods for use in process control and manufacturing automation applications to facilitate interoperability.