The COM UA Proxy converts all the ItemIds in the Write into valid NodeIds by replacing the ‘-’ with ‘=’. It converts the Value, Quality and Timestamp (VQT) to a DataValue structure as per the mapping in Figure A.16. and calls the OPC UA Write Service for the Value Attribute.

If the Write Service call fails or if there are errors for some of the Nodes, then the StatusCodes of these Nodes are mapped to the error code by the COM UA Proxy.

The mapping of the OPC UA Status code to OPC DA Write Error code (in the COM UA Proxy) is shown in Table A.67:

Table A.67 – OPC UA Write error code mapping

OPC UA Status Code	OPC DA Error ID
Bad_TypeMismatch	E_BADTYPE
Bad_OutOfMemory	E_OUTOFMEMORY
Bad_NodeIdInvalid	E_INVALIDITEMID
Bad_NodeIdUnknown	E_UNKNOWNITEMID
Bad_NotWritable	E_BADRIGHTS
Bad_UserAccessDenied	E_ACCESSDENIED
Bad_AttributeIdInvalid	E_UNKNOWNITEMID
Bad_WriteNotSupported	E_NOTSUPPORTED
Bad_OutOfRange	E_RANGE