OPC Data Access (OPC-DA) is the original OPC specification. Its common use it to move real-time data from PLCs, DCSs, and other control devices to HMIs and other display clients, but it gained broader usage scope over the time. The current version of the OPC Data Access specification is 3.0. It leverages earlier versions while improving the browsing capabilities and incorporating XML-DA Schema.
OPC-DA is fully supported by QuickOPC. You can develop OPC clients with data access capabilities easily with help of QuickOPC components.
In addition to the COM/DCOM based OPC-DA, QuickOPC also supports the SOAP-based OPC XML-DA specification.
Most developers use the procedural coding model to create their applications. You can also: