The OPC Foundation has defined interfaces to Data Access Servers, Event Servers, Batch Servers, and History Data Access Servers. These servers have information that is valuable to the enterprise, and is currently being provided to enterprise applications via OLE/COM based interfaces.
XML, the eXtensible Markup Language, and XML-based schema languages provide another means to describe and exchange structured information between collaborating applications. XML is a technology that is more readily available across a wide range of platforms. OPC XML-Data Access (OPC XML-DA) is the OPC Foundation’s adoption of the XML set of technologies to facilitate the exchange of plant data across the internet, and upwards into the enterprise domain.
The purpose of this document is to continue OPC’s goal of enabling and promoting interoperability of applications. The XML-DA based interfaces will simplify sharing and exchange of OPC data amongst the various levels of the plant hierarchy (low level devices and up to enterprise systems), and to a wider range of platforms.
The goal for this document is to provide:
Support for OPC Data Access 2.0x/3.0 data
- Support for HTTP, and SOAP
- Support for Subscription based services
- Support for a Security approach