5.1 Overview

The goal of the mapping is to provide a lossless, bi-directional mapping of built-in data types from OPC UA to XML and vice versa.

  • In some cases, it is possible to map an OPC UA DataType to an XML data type directly (see 5.2). In most cases, this is a lossless mapping, sometimes there is a loss of precision or information.
  • In other cases, there is an OPC UA DataType without a corresponding XML data type. For those cases, the XML Schema defined in OPC 10000-6, Annex D, provides appropriate XML data types that can be used. The mapping to those XML data types is defined in 5.3.
  • Finally, there are cases where there is an XML data type without a corresponding OPC UA DataType. For those cases, an OPC UA Information Model is defined (see 6). The mapping is defined in 5.4.