OPC UA Variable Types
OPC UA supports multiple data types (variables) for various cases. The following table lists the current primitive variable types. You can use them to compose or derive other types of variables.
|
ID |
Name |
Nullable |
Default |
Description |
|---|---|---|---|---|
|
1 |
Boolean |
No |
false |
true or false |
|
2 |
SByte |
No |
0 |
integer [−128, ..., 127] |
|
3 |
Byte |
No |
0 |
integer [0, ..., 255] |
|
4 |
Int16 |
No |
0 |
integer [−32,768, ..., 32,767] |
|
5 |
UInt16 |
No |
0 |
integer [0, ..., 65,535] |
|
6 |
Int32 |
No |
0 |
integer [−2,147,483,648, ..., 2,147,483,647] |
|
7 |
UInt32 |
No |
0 |
integer [0, ..., 4,294,967,295] |
|
8 |
Int64 |
No |
0 |
integer [−9,223,372,036,854,775,808, ..., 9,223,372,036,854,775,807] |
|
9 |
UInt64 |
No |
0 |
integer [0, ..., 18,446,744,073,709,551,615] |
|
10 |
Float |
No |
0 |
IEEE single precision floating point value (32 bit) |
|
11 |
Double |
No |
0 |
IEEE double precision floating point value (64 bit) |
|
12 |
String |
Yes |
null |
sequence of Unicode characters |
|
13 |
DateTime |
Yes |
DateTime.MinValue |
An instance in time |
|
14 |
Guid |
Yes |
All zeros |
A 16-byte value that can be used as a globally unique identifier |
|
15 |
ByteString |
Yes |
null |
A sequence of octets |
|
16 |
XmlElement |
Yes |
null |
A sequence of Unicode characters that is an XML element |
|
17 |
NodeId |
Yes |
All fields set to default |
An identifier for a node in the address space of an OPC UA Server |
|
18 |
ExpandedNodeId |
Yes |
All fields set to default |
A NodeId that allows the namespace URI to be specified instead of an index |
|
19 |
StatusCode |
No |
Good |
A numeric identifier for an error or condition that is associated with a value or an operation |
|
20 |
QualifiedName |
Yes |
All fields set to default |
A name qualified by a namespace |
|
21 |
LocalizedText |
Yes |
All fields set to default |
Human readable text with an optional locale identifier |
|
22 |
ExtensionObject |
Yes |
All fields set to default |
A structure that contains an application specific data type that may not be recognized by the receiver |
|
23 |
DataValue |
Yes |
All fields set to default |
A data value with an associated status code and timestamps |
|
24 |
Variant |
Yes |
Null |
A union of all of the types specified above |
|
25 |
DiagnosticInfo |
Yes |
No fields specified |
A structure that contains detailed error and diagnostic information associated with a StatusCode |