OPC delivers a standard interface designed to meet the needs of automation, enabling applications from different vendors to exchange information. By using OPC as a common interface, you can choose from a variety of products, assembling them to meet the needs of your specific application.
The first generation of OPC developed primarily into three distinct specifications: OPC-DA, designed for real-time data access; OPC-A&E, designed for alarm and event message access; and OPC-HDA, designed for historian data access. Developers of data acquisition products could pick and choose from these specifications and implement the most suitable OPC functionality. Because most of the automation world revolves around real-time data access, OPC-DA became the most widely supported specification followed by OPC-A&E and, finally, by OPC-HDA.
OPC-UA promises to deliver exactly what is needed to solve the problems of the past, while delivering significant benefits for the future. For all the details, download the whitepaper.