What is OPC DA/UA?

OPC (OLE for Process Control) is a standard for enabling communication between industrial automation devices and software applications. OPC DA (Data Access) is the original OPC standard based on Microsoft's COM/DCOM technology. OPC UA (Unified Architecture) is a newer, platform-independent standard designed to overcome the limitations of OPC DA, offering improved security, scalability, and data modeling capabilities. OPC DA is commonly used for real-time data exchange in Windows-based industrial environments, while OPC UA is used for broader interoperability across different operating systems and platforms, including the cloud, and for more complex data modeling and information exchange scenarios. They are commonly used to provide a standardized way for various industrial control systems (PLCs, HMIs, etc.) to communicate with each other and with higher-level systems like MES and ERP.