This is a subtype of the UInt32 DataTypewith the OptionSetValues Propertydefined. It is used to define the Attributeaccess restrictions of a Node. The AttributeWriteMaskis formally defined in Table 43.

If a bit is set to 0, it means the Attributeis not writable. If a bit is set to 1, it means it is writable. If a Nodedoes not support a specific Attribute, the corresponding bit has to be set to 0.

Table 43– Bit mask for WriteMask and UserWriteMask

Field

Bit

Description

AccessLevel

0

Indicates if the AccessLevel Attribute is writable.

ArrayDimensions

1

Indicates if the ArrayDimensions Attribute is writable.

BrowseName

2

Indicates if the BrowseName Attribute is writable.

ContainsNoLoops

3

Indicates if the ContainsNoLoops Attribute is writable.

DataType

4

Indicates if the DataType Attribute is writable.

Description

5

Indicates if the Description Attribute is writable.

DisplayName

6

Indicates if the DisplayName Attribute is writable.

EventNotifier

7

Indicates if the EventNotifier Attribute is writable.

Executable

8

Indicates if the Executable Attribute is writable.

Historizing

9

Indicates if the Historizing Attribute is writable.

InverseName

10

Indicates if the InverseName Attribute is writable.

IsAbstract

11

Indicates if the IsAbstract Attribute is writable.

MinimumSamplingInterval

12

Indicates if the MinimumSamplingInterval Attribute is writable.

NodeClass

13

Indicates if the NodeClass Attribute is writable.

NodeId

14

Indicates if the NodeId Attribute is writable.

Symmetric

15

Indicates if the Symmetric Attribute is writable.

UserAccessLevel

16

Indicates if the UserAccessLevel Attribute is writable.

UserExecutable

17

Indicates if the UserExecutable Attribute is writable.

UserWriteMask

18

Indicates if the UserWriteMask Attribute is writable.

ValueRank

19

Indicates if the ValueRank Attribute is writable.

WriteMask

20

Indicates if the WriteMask Attribute is writable.

ValueForVariableType

21

Indicates if the Value Attributeis writable for a VariableType. It does not apply for Variablessince this is handled by the AccessLeveland UserAccessLevel Attributesfor the Variable. For Variablesthis bit shall be set to 0.

DataTypeDefinition

22

Indicates if the DataTypeDefinition Attribute is writable.

RolePermissions

23

Indicates if the RolePermissions Attribute is writable.

AccessRestrictions

24

Indicates if the AccessRestrictions Attribute is writable.

AccessLevelEx

25

Indicates if the AccessLevelEx Attribute is writable.

Reserved

26:31

Reserved for future use. Shall always be zero.