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 specification or if it is server specific.

For all Nodesspecified in this specification, the Attributesnamed in Table 3shall be set as specified in the table.

Table 3– Common Node Attributes

Attribute

Value

DisplayName

The DisplayNameis a LocalizedText. Each server shall provide the DisplayNameidentical to the BrowseNameof the Nodefor the LocaleId “en”. Whether the server provides translated names for other LocaleIds is 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 3.4.2.1.

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 specification.

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.

For all Objectsspecified in this specification, the Attributesnamed in Table 4shall be set as specified in the Table 4. The definitions for the Attributescan be found in [OPC 10000-5].

Table 4– Common Object Attributes

Attribute

Value

EventNotifier

Whether the Nodecan be used to subscribe to Eventsor not is server specific.

For all Variablesspecified in this specification, the Attributesnamed in Table 5shall be set as specified in the table. The definitions for the Attributescan be found in [OPC 10000-5].

Table 5– 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 specification, 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 behaviour 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.

For all VariableTypesspecified in this specification, the Attributesnamed in Table 6shall be set as specified in the table. The definitions for the Attributescan be found in [OPC 10000-5].

Table 6– 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 behaviour 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.

For all Methodsspecified in this specification, the Attributesnamed in Table 7shall be set as specified in the table. The definitions for the Attributescan be found in [OPC 10000-5].

Table 7– Common Method Attributes

Attributes

Value

Executable

All Methodsdefined in this specification 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.