The COM UA Proxy converts the OPC UA Data Value to the corresponding OPC DA Variant type. The mapping is shown in Table A.64. For DataTypes that are subtypes of an existing base DataType the conversion for the Base DataType is used.
Table A.64 – DataTypes and Mapping
OPC UA Data type (In UA Server) |
Variant Data Type (In DA server) |
Int16 |
VT_I2 |
Int32 |
VT_I4 |
Float |
VT_R4 |
Double |
VT_R8 |
Decimal |
VT_DECIMAL |
String |
VT_BSTR |
Boolean |
VT_BOOL |
Byte |
VT_UI1 |
SByte |
VT_I1 |
UInt16 |
VT_UI2 |
UInt32 |
VT_UI4 |
Int64 |
VT_I8 |
UInt64 |
VT_UI8 |
Guid |
VT_BSTR |
DateTime |
VT_DATE |
NodeId |
VT_BSTR |
XmlElement |
VT_BSTR |
ExpandedNodeId |
VT_BSTR |
QualifiedName |
VT_BSTR |
LocalizedText |
VT_BSTR |
StatusCode |
VT_UI4 |
ExtensionObject |
Array of VT_UI1 |
Array of above OPC UA types |
Array of corresponding Variant type |