OPC Data Access (OPC DA) provides access to real time automation data. Using OPC DA, software applications can retrieve real-time data to enable them to monitor a given process. In that scenario, OPC DA is used for data acquisition. OPC DA can also be used to enable a software application to write data to a control system. This enables OPC DA applications to handle supervisory control. Thus, OPC DA is well suited for Supervisory Control and Data Acquisition (SCADA) scenarios. OPC DA is typically used by almost all process control applications that are used as an HMI, Historian, Advanced Process Control (APC), Maintenance, ERP (Enterprise Resource Planning), Analysis, Optimization, etc.

OPC DA enables the exchange of real-time process data, in other words, the latest values. To get the previous values, applications must use OPC HDA (Historical Data Access). The OPC Foundation (www.opcfoundation.org) is responsible for defining and maintaining the OPC Batch specification.

See also: OPC HDA