OPC DA (OPC Data Access) is a communication protocol and standard in the OPC (OLE for Process Control) family. It is designed for real-time data exchange between software applications and industrial automation systems, such as SCADA (Supervisory Control and Data Acquisition) and process control systems.
OPC DA provides a standardized method for accessing and sharing data from diverse data sources, including sensors, devices, and process equipment. It enables seamless interoperability and communication between different applications and systems, regardless of the underlying hardware or communication protocols.
Key features and characteristics of OPC DA include:
- Data Access: OPC DA allows client applications to access real-time data from OPC servers. It supports both read and write operations, enabling applications to retrieve data values from sensors, control devices, and other data sources, as well as send commands or set values to control the process.
- Tag-Based Model: OPC DA organizes data using a tag-based model. Each data item or variable is assigned a unique tag or address, allowing clients to access specific data points by their tags.
- Asynchronous Data Updates: OPC DA supports asynchronous data updates, where the server notifies the client application when there is a change in the data value. This event-driven approach reduces network traffic and improves efficiency by transmitting data only when it changes.
- Historical Data Access: OPC DA allows clients to access historical data stored in OPC servers. It provides methods to retrieve data values over a specified time range, facilitating analysis, reporting, and trend analysis.
- Interoperability: OPC DA ensures interoperability between different applications and systems by providing a standardized interface and data exchange format. It abstracts the underlying communication protocols and hardware, allowing applications to communicate with OPC servers regardless of the specific technologies employed.
- Wide Industry Adoption: OPC DA is widely adopted in various industries, including manufacturing, oil and gas, utilities, pharmaceuticals, and more. Its popularity stems from its ability to facilitate seamless integration and data exchange between diverse systems and devices.