OPC UA Server Data Types

OPC UA servers store data retrieved from sensors, actuators and other data sources, in variable nodes. Each variable node stores and retrieves data as a specific server data type, either as a single value or an array of values. The ServerDataType property of an OPC UA node object describes the OPC UA data type in which the server stores the node Value.

The OPC UA Standard defines simple data types and structures which consist of fields containing other data types. Vendors and standards organizations can define custom data types using these standard types. These custom data types are represented on the server as multiple nodes, each containing a standard data type.

When you read data from the server, MATLAB^® translates the value into the corresponding MATLAB data type. When you write data to the server, specify the values in the MATLAB data type that corresponds to the OPC UA data type.

This table lists the OPC UA Standard data types and their corresponding MATLAB data types.

OPC UA Data Type	MATLAB Data Type	Read	Write	Notes
Boolean	Logical	✔	✔
Byte	uint8	✔	✔
ByteString	uint8 vector	✔		Arrays are returned as cell arrays of uint8 values.
DateTime	Datetime	✔	✔	Numeric values written are interpreted as MATLAB datetime.
Double	Double	✔	✔
ExpandedNodeId	Structure	✔
Float	Single	✔	✔
Guid	Character vector	✔		Arrays are returned as cell arrays of encoded character vectors.
Int16	int16	✔	✔
Int32	int32	✔	✔
Int64	int64	✔	✔
LocalizedText	Character vector	✔	✔	Arrays are returned as cell arrays of character vectors.
NodeId	Character vector	✔		Arrays are returned as cell arrays of encoded character vectors.
QualifiedName	Character vector	✔		Arrays are returned as cell arrays of encoded character vectors.
SByte	int8	✔	✔
String	Character vector	✔	✔	Arrays are returned as cell arrays of character vectors.
UInt16	uint16	✔	✔
UInt32	uint32	✔	✔
UInt64	uint64	✔	✔
XmlElement	Character vector	✔		Arrays are returned as cell arrays of character vectors.