Devices - 3.3.3 Common Attributes

The Attributesof Nodes, their DataTypesand descriptions are defined in OPC 10000-3. Attributes not marked as optional are mandatory and shall be provided by a Server. The following tables define if the Attributevalue is defined by this document or if it is server-specific.

For all Nodesspecified in this document, the Attributesnamed in Table 7shall be set as specified in the table.

Table 7– Common Node Attributes

Attribute	Value
DisplayName	The DisplayNameis a LocalizedText. Each Servershall provide the DisplayNameidentical to the BrowseNameof the Nodefor the LocaleId“en”. Whether the server provides translated names for other LocaleIdsare server-specific.
Description	Optionally a server-specific description is provided.
NodeClass	Shall reflect the NodeClassof the Node.
NodeId	The NodeIdis described by BrowseNamesas defined in 3.3.2.1.
WriteMask	Optionally the WriteMask Attributecan be provided. If the WriteMask Attributeis provided, it shall set all non-server-specific Attributesto not writable. For example, the Description Attributemay be set to writable since a Servermay provide a server-specific description for the Node. The NodeIdshall not be writable, because it is defined for each Nodein this document.
UserWriteMask	Optionally the UserWriteMask Attributecan be provided. The same rules as for the WriteMask Attributeapply.
RolePermissions	Optionally server-specific role permissions can be provided.
UserRolePermissions	Optionally the role permissions of the current Session can be provided. The value is server-specific and depends on the RolePermissions Attribute(if provided) and the current Session.
AccessRestrictions	Optionally server-specific access restrictions can be provided.

3.3.3.2 Objects

For all Objectsspecified in this document, the Attributesnamed in Table 8shall be set as specified in the Table 8. The definitions for the Attributescan be found in OPC 10000-3.

Table 8– Common Object Attributes

Attribute	Value
EventNotifier	Whether the Nodecan be used to subscribe to Eventsor not is server-specific.

3.3.3.3 Variables

For all Variablesspecified in this document, the Attributesnamed in Table 9shall be set as specified in the table. The definitions for the Attributescan be found in OPC 10000-3.

Table 9– Common Variable Attributes

Attribute	Value
MinimumSamplingInterval	Optionally, a server-specific minimum sampling interval is provided.
AccessLevel	The access level for Variablesused for type definitions is server-specific, for all other Variablesdefined in this document, the access level shall allow reading; other settings are server-specific.
UserAccessLevel	The value for the UserAccessLevel Attributeis server-specific. It is assumed that all Variablescan be accessed by at least one user.
Value	For Variablesused as InstanceDeclarations,the value is server-specific; otherwise it shall represent the value described in the text.
ArrayDimensions	If the ValueRankdoes not identify an array of a specific dimension (i.e. ValueRank<= 0) the ArrayDimensionscan either be set to null or the Attributeis missing. This behavior is server-specific. If the ValueRankspecifies an array of a specific dimension (i.e. ValueRank> 0) then the ArrayDimensions Attributeshall be specified in the table defining the Variable.
Historizing	The value for the Historizing Attributeis server-specific.
AccessLevelEx	If the AccessLevelEx Attributeis provided, it shall have the bits 8, 9, and 10 set to 0, meaning that read and write operations on an individual Variableare atomic, and arrays can be partly written.

3.3.3.4 VariableTypes

For all VariableTypesspecified in this document, the Attributesnamed in Table 10shall be set as specified in the table. The definitions for the Attributescan be found in OPC 10000-3.

Table 10– Common VariableType Attributes

Attributes	Value
Value	Optionally a server-specific default value can be provided.
ArrayDimensions	If the ValueRankdoes not identify an array of a specific dimension (i.e. ValueRank<= 0) the ArrayDimensionscan either be set to null or the Attributeis missing. This behavior is server-specific. If the ValueRankspecifies an array of a specific dimension (i.e. ValueRank> 0) then the ArrayDimensions Attributeshall be specified in the table defining the VariableType.

3.3.3.5 Methods

For all Methodsspecified in this document, the Attributesnamed in Table 11shall be set as specified in the table. The definitions for the Attributescan be found in OPC 10000-3.

Table 11– Common Method Attributes

Attributes	Value
Executable	All Methodsdefined in this document shall be executable (Executable Attributeset to “True”), unless it is defined differently in the Methoddefinition.
UserExecutable	The value of the UserExecutable Attributeis server-specific. It is assumed that all Methodscan be executed by at least one user.