Errata exists for this version of the document.
All OPC UA DataEncodings are based on rules that are defined for a standard set of built-in types. These built-in types are then used to construct structures, arrays and Messages. The built-in types are described in Table 1.
ID |
Name |
Description |
1 |
Boolean |
A two-state logical value (true or false). |
2 |
SByte |
An integer value between −128 and 127 inclusive. |
3 |
Byte |
An integer value between 0 and 255 inclusive. |
4 |
Int16 |
An integer value between −32 768 and 32 767 inclusive. |
5 |
UInt16 |
An integer value between 0 and 65 535 inclusive. |
6 |
Int32 |
An integer value between −2 147 483 648 and 2 147 483 647 inclusive. |
7 |
UInt32 |
An integer value between 0 and 4 294 967 295 inclusive. |
8 |
Int64 |
An integer value between −9 223 372 036 854 775 808 and 9 223 372 036 854 775 807 inclusive. |
9 |
UInt64 |
An integer value between 0 and 18 446 744 073 709 551 615 inclusive. |
10 |
Float |
An IEEE single precision (32 bit) floating point value. |
11 |
Double |
An IEEE double precision (64 bit) floating point value. |
12 |
String |
A sequence of Unicode characters. |
13 |
DateTime |
An instance in time. |
14 |
Guid |
A 16-byte value that can be used as a globally unique identifier. |
15 |
ByteString |
A sequence of octets. |
16 |
XmlElement |
An XML element. |
17 |
NodeId |
An identifier for a node in the address space of an OPC UA Server. |
18 |
ExpandedNodeId |
A NodeId that allows the namespace URI to be specified instead of an index. |
19 |
StatusCode |
A numeric identifier for an error or condition that is associated with a value or an operation. |
20 |
QualifiedName |
A name qualified by a namespace. |
21 |
LocalizedText |
Human readable text with an optional locale identifier. |
22 |
ExtensionObject |
A structure that contains an application specific data type that may not be recognized by the receiver. |
23 |
DataValue |
A data value with an associated status code and timestamps. |
24 |
Variant |
A union of all of the types specified above. |
25 |
DiagnosticInfo |
A structure that contains detailed error and diagnostic information associated with a StatusCode. |
Most of these data types are the same as the abstract types defined in OPC 10000-3 and OPC 10000-4. However, the ExtensionObject and Variant types are defined in this standard. In addition, this standard defines a representation for the Guid type defined in OPC 10000-3.