It is assumed that the basic concepts of OPC UA information modelling are understood in this document. This specification will use these concepts to describe the OPC UA LADS Information Model. For the purposes of this document, the terms and definitions given in OPC 10000-1, OPC 10000-2, OPC 10000-3, OPC 10000-4, OPC 10000-5, OPC 10000-6, OPC 10000-7, OPC 10000-8, OPC 10000-100, OPC 40001-1 as well as the following apply.
Note that OPC UA terms and terms defined in this document are italicized in the document.
Analytical or laboratory device, also known as an instrument.
Instrument used in a laboratory to carry out specific tasks and generate the results of an analysis.
Instrument to study scientific data and provide analytical results.
Component of a device. (See OPC 10000-100.)
Non-local location in the lab network or the Internet.
Aggregation of functions to achieve a specific outcome. (Typically utilized by only one user at a time, it exposes its current state via a state machine and might optionally include a Program Manager.)
Action to achieve a specific outcome, organized by a Functional Unit. (Typical functions include but are not limited to sensors, controllers, actuators, timers, etc. They may utilize one or more tangible components.)
Organization of objects to manage program templates, run programs, and manage results.
General configuration of settings or formats to be used as a basis for further definition of individual programs.
Asset that causes a machine or other device to operate.
Asset that directs or regulates something.
Asset that detects or measures a physical property.
Asset that measures or records the amount of time taken by a process or activity.
Acoustic or electronic warning that is issued to signal an abnormal condition.
Alert issued to notify a user of an event or condition.
System that oversees and coordinates operations of lower-level subsystems or processes.
Unique identifier for a task within the supervisory system.
Note: In a Supervisory System, a Job consists of multiple Tasks, where a Task is the smallest atomic unit of operation that can be executed on a LADS Functional Unit. A SupervisoryTaskId is defined as the unique identifier for a Task within the Supervisory System.
Unique identifier for a specific program execution on a device.
Note: The "DeviceProgramRunId" is a unique identifier internally generated by a device for tracking a specific program execution. On the other hand, "SupervisoryTaskId" is an identifier used in a Supervisory System to denote a specific Task within the larger workflow.
Unique identifier for a job.
Note: A ‘Job’ generally refers to a specific Task or series of operations to be performed by a system.
Note: SupervisoryJobId is also commonly known as LotId in Discrete Part Manufacturing processes, or BatchId in Batch processes.
CSCompanion Specification
ELNElectronic Laboratory Notebook
ERPEnterprise Resource Planning
HMIHuman Machine Interface
LESLaboratory Execution System
LIMSLaboratory Information Management System
MESManufacturing Execution System
PIDProportional Integral Derivative controller
PMSProduction Management System
SCADASupervisory Control and Data Acquisition
Node definitions are specified using tables (see Table 2).
Attributes are defined by providing the Attribute name and a value, or a description of the value.
References are defined by providing the ReferenceType name, the BrowseName of the TargetNode and its NodeClass.
- If the TargetNode is a component of the Node being defined in the table, the Attributes of the composed Node are defined in the same row of the table.
- The DataType is only specified for Variables; “[<number>]” indicates a single-dimensional array, for multi-dimensional arrays the expression is repeated for each dimension (e.g.,[2][3] for a two-dimensional array). For all arrays, the ArrayDimensions is set as identified by <number> values. If no <number> is set, the corresponding dimension is set to 0, indicating an unknown size. If no number is provided at all the ArrayDimensions can be omitted. If no brackets are provided, it identifies a scalar DataType and the ValueRank is set to the corresponding value (see OPC 10000-3). In addition, ArrayDimensions is set to null or is omitted. If it can be Any or ScalarOrOneDimension, the value is put into “{<value>}”, so either “{Any}” or “{ScalarOrOneDimension}”, the ValueRank is set to the corresponding value (see OPC 10000-3), and ArrayDimensions is set to null or omitted. Examples are given in Table 1.
Table 1 – Examples of DataTypes
Notation |
DataType |
ValueRank |
ArrayDimensions |
Description |
0:Int32 |
0:Int32 |
-1 |
omitted or null |
A scalar Int32. |
0:Int32{OneOreMoreDimensions} |
0:Int32 |
0 |
Omitted or null |
An int32 array with one or more dimensions. |
0:Int32[] |
0:Int32 |
1 |
omitted or {0} |
Single-dimensional array of Int32 with an unknown size. |
0:Int32[][] |
0:Int32 |
2 |
omitted or {0,0} |
Two-dimensional array of Int32 with unknown sizes for both dimensions. |
0:Int32[3][] |
0:Int32 |
2 |
{3,0} |
Two-dimensional array of Int32 with a size of 3 for the first dimension and an unknown size for the second dimension. |
0:Int32[5][3] |
0:Int32 |
2 |
{5,3} |
Two-dimensional array of Int32 with a size of 5 for the first dimension and a size of 3 for the second dimension. |
0:Int32{Any} |
0:Int32 |
-2 |
omitted or null |
An Int32 where it is unknown if it is scalar or array with any number of dimensions. |
0:Int32{ScalarOrOneDimension} |
0:Int32 |
-3 |
omitted or null |
An Int32 where it is either a single-dimensional array or scalar. |
- The TypeDefinition is specified for Objects and Variables.
- The TypeDefinition column specifies a symbolic name for a NodeId; i.e., the specified Node points with a HasTypeDefinition Reference to the corresponding Node.
- The ModellingRule of the referenced component is provided by specifying the symbolic name of the rule in the ModellingRule column. In the AddressSpace, the Node shall use a HasModellingRule Reference to point to the corresponding ModellingRule Object.
If the NodeId of a DataType is provided, the symbolic name of the Node representing the DataType shall be used.
Note that if a symbolic name of a different Namespace is used, it is prefixed by the NamespaceIndex (see 3.4.2.2).
Nodes of different NodeClasses cannot be defined in the same table; therefore, only the used ReferenceType, their NodeClass and their BrowseName are specified. A reference to another part of this document points to their definition. This is illustrated in Table 2. If no components are provided, the DataType, TypeDefinition and Other columns may be omitted and only a Comment column is introduced to point to the Node definition.
Each Type Node or well-known Instance Node defined shall have one or more ConformanceUnits defined in 9.1 that require the Node to be in the AddressSpace.
The relations between Nodes and ConformanceUnits are defined at the end of the tables defining the Nodes, with one row per ConformanceUnit. The ConformanceUnits are reflected in the Category element for the Node definition in the UANodeSet (see OPC 10000-6).
The list of ConformanceUnits in the UANodeSet allows Servers to optimize resource consumption by using a list of supported ConformanceUnits to select a subset of the Nodes in an Information Model.
When a Node is selected in this way, all dependencies implied by the References are also selected.
Dependencies exist if the Node is the source of a HasTypeDefinition, HasInterface, HasAddIn or any HierarchicalReference. Dependencies also exist if the Node is the target of a HasSubtype Reference. For Variables and VariableTypes, the value of the DataType Attribute is a dependency. For DataType Nodes, any DataTypes referenced in the DataTypeDefinition Attribute are also dependencies.
For additional details see OPC 10000-5.
Table 2 provides an example of the table format. If no components are provided, the DataType, TypeDefinition and ModellingRule columns may be omitted and only a Comment column is introduced to point to the Node definition.
Table 2 – Type Definition Table
Attribute |
Value |
||||
Attribute name |
Attribute value. If it is an optional Attribute that is not set “--” is used. |
||||
|
|
||||
References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
Other |
ReferenceType name |
BrowseName of the target Node. |
DataType of the referenced Node, only applicable for Variables. |
TypeDefinition of the referenced Node, only applicable for Variables and Objects. |
Additional characteristics of the TargetNode such as the ModellingRule or AccessLevel. |
|
NOTE Notes referencing footnotes of the table content. |
|||||
Conformance Units |
|||||
Name of ConformanceUnit, one row per ConformanceUnit |
Components of Nodes can be complex; that is, containing components themselves. The TypeDefinition, NodeClass and DataType can be derived from the Type definitions, and the symbolic name can be created as defined in 3.4.3.1. Therefore, those Nodes containing components are not explicitly specified; they are implicitly specified by the Type definitions.
The Other column defines additional characteristics of the Node. Examples of characteristics that can appear in this column are shown in Table 3.
Table 3 – Examples of Other Characteristics
Name |
Short Name |
Description |
0:Mandatory |
M |
The Node has the Mandatory ModellingRule. |
0:Optional |
O |
The Node has the Optional ModellingRule. |
0:MandatoryPlaceholder |
MP |
The Node has the MandatoryPlaceholder ModellingRule. |
0:OptionalPlaceholder |
OP |
The Node has the OptionalPlaceholder ModellingRule. |
ReadOnly |
RO |
The Node AccessLevel has the CurrentRead bit set but not the CurrentWrite bit. |
ReadWrite |
RW |
The Node AccessLevel has the CurrentRead and CurrentWrite bits set. |
WriteOnly |
WO |
The Node AccessLevel has the CurrentWrite bit set but not the CurrentRead bit. |
If multiple characteristics are defined, they are separated by commas. The name or the short name may be used.
To provide information about additional References, the format as shown in Table 4 is used.
Table 4 – <some>Type Additional References
SourceBrowsePath |
Reference Type |
Is Forward |
TargetBrowsePath |
SourceBrowsePath is always relative to the TypeDefinition. Multiple elements are defined as separate rows of a nested table. |
ReferenceType name |
True = forward Reference. |
TargetBrowsePath points to another Node, which can be a well-known instance or a TypeDefinition. You can use BrowsePaths here as well, which are either relative to the TypeDefinition or absolute. If absolute, the first entry needs to refer to a Type or well-known instance, uniquely identified within a Namespace by the BrowseName. |
References can be made to any other Node.
To provide information about sub-components, the format as shown in Table 5 is used.
Table 5 – <some>Type additional subcomponents
BrowsePath |
References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
Others |
BrowsePath is always relative to the TypeDefinition. Multiple elements are defined as separate rows of a nested table |
NOTE: Same as for Table 2 |
The Type definition table provides columns to specify the values for required Node Attributes for InstanceDeclarations. To provide information about additional Attributes, the format as shown in Table 6 is used.
Table 6 – <some>Type Attribute Values for Child Nodes
BrowsePath |
<Attribute name> Attribute |
BrowsePath is always relative to the TypeDefinition. Multiple elements are defined as separate rows of a nested table |
The values of attributes are converted to text by applying the reversible JSON encoding rules defined in OPC 10000-6. If the JSON encoding of a value is a JSON string or a JSON number, that value is entered in the value field. Quotation marks are not included. If the DataType includes a NamespaceIndex (QualifiedNames, NodeIds or ExpandedNodeIds), the notation used for BrowseNames is used. If the value is an Enumeration, the name of the enumeration value is entered. If the value is a Structure, a sequence of name and value pairs is entered. Each pair is followed by a new line. The name is followed by a colon. The names are the names of the fields in the DataTypeDefinition. If the value is an array of non-structures, a sequence of values is entered. Each value is followed by a new line. If the value is an array of Structures or a Structure with fields that are arrays or with nested Structures, the complete JSON array or JSON object is entered. Quotation marks are not included. |
There can be multiple columns to define more than one Attribute.
The NodeIds of all Nodes described in this standard are only symbolic names. Annex A defines the actual NodeIds.
The symbolic name of each Node defined in this document is its BrowseName, or, when it is part of another Node, the BrowseName of the other Node, followed by “.” and its own BrowseName. In this case, “part of” means that the whole has a HasProperty or HasComponent Reference to its part. Since all Nodes which are not part of another Node have a unique name in this document, the symbolic name is unique.
The NamespaceUri for all NodeIds defined in this document is defined in Annex A. The NamespaceIndex for this NamespaceUri is vendor specific and depends on the position of the NamespaceUri in the server Namespace table.
Note that this document not only defines concrete Nodes, but also requires for some Nodes to be generated; for example, one for each Session running on the Server. The NodeIds of those Nodes are Server specific, including the Namespace. However, the NamespaceIndex of those Nodes cannot be the NamespaceIndex used for the Nodes defined in this document, as they are not defined by this document but are generated by the Server.
The text part of the BrowseNames for all Nodes defined in this document is specified in the tables defining the Nodes. The NamespaceUri for all BrowseNames defined in this document is defined in 10.2.
For InstanceDeclarations of NodeClass Objects and Variables that are placeholders (OptionalPlaceholder and MandatoryPlaceholder ModellingRule), the BrowseName and the DisplayName are enclosed in angle brackets (<>) as recommended in OPC 10000-3.
If a BrowseName is not defined by this document, a Namespace index prefix is added to the BrowseName (e.g., prefix '0' leading to ‘0:EngineeringUnits’ or prefix '2' leading to ‘2:DeviceRevision’). This is typically necessary if a Property of another specification is overwritten or used in the OPC UA types defined in this document. Table 146 provides a list of Namespaces and their indexes as used in this document.
The Attributes of Nodes, their DataTypes and 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 whether the Attribute value is defined by this document or if it is server specific.
For all Nodes specified in this document, the Attributes named in Table 7 shall be set as specified in the table.
Table 7 – Common Node Attributes
Attribute |
Value |
DisplayName |
The DisplayName is a LocalizedText. Each Server shall provide the DisplayName identical to the BrowseName of the Node for the LocaleId “en” unless specified differently in the specification. Whether the Server provides translated names for other LocaleIds is server specific. |
Description |
Optionally a server-specific description is provided. |
NodeClass |
|
NodeId |
The NodeId is described by BrowseNames as defined in 3.4.2.1. |
WriteMask |
Optionally the WriteMask Attribute can be provided. If the WriteMask Attribute is provided, it shall set all non-server-specific Attributes to not writeable. For example, the Description Attribute may be set to writeable since a Server may provide a server-specific description for the Node. The NodeId shall not be writeable, because it is defined for each Node in this document. |
UserWriteMask |
Optionally the UserWriteMask Attribute can be provided. The same rules as for the WriteMask Attribute apply. |
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 Objects specified in this document, the Attributes named in Table 8 shall be set as specified in the table. The definitions for the Attributes can be found in OPC 10000-3.
Table 8 – Common Object Attributes
Attribute |
Value |
EventNotifier |
Whether or not the Node can be used to subscribe to Events is server specific. |
For all Variables specified in this document, the Attributes named in Table 9 shall be set as specified in the table. The definitions for the Attributes can 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 Variables used for Type definitions is server specific, for all other Variables defined in this document, the access level shall allow reading; other settings are server specific. |
UserAccessLevel |
The value for the UserAccessLevel Attribute is server specific. It is assumed that all Variables can be accessed by at least one user. |
Value |
For Variables used as InstanceDeclarations, the value is server specific; otherwise, it shall represent the value described in the text. |
ArrayDimensions |
If the ValueRank does not identify an array of a specific dimension (i.e., ValueRank <= 0) the ArrayDimensions can either be set to null or the Attribute is missing. This behaviour is server specific. If the ValueRank specifies an array of a specific dimension (i.e., ValueRank > 0) then the ArrayDimensions Attribute shall be specified in the table defining the Variable. |
Historizing |
The value for the Historizing Attribute is server specific. |
AccessLevelEx |
If the AccessLevelEx Attribute is provided, it shall have the bits 8, 9, and 10 set to 0, meaning that read and write operations on an individual Variable are atomic, and arrays can be partly written. |
For all VariableTypes specified in this document, the Attributes named in Table 10 shall be set as specified in the table. The definitions for the Attributes can 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 ValueRank does not identify an array of a specific dimension (i.e., ValueRank <= 0) the ArrayDimensions can either be set to null or the Attribute is missing. This behaviour is server specific. If the ValueRank specifies an array of a specific dimension (i.e., ValueRank > 0) then the ArrayDimensions Attribute shall be specified in the table defining the VariableType. |
For all Methods specified in this document, the Attributes named in Table 11 shall be set as specified in the table. The definitions for the Attributes can be found in OPC 10000-3.
Table 11 – Common Method Attributes
Attributes |
Value |
Executable |
All Methods defined in this document shall be executable (Executable Attribute set to “True”) unless it is defined differently in the Method definition. |
UserExecutable |
The value of the UserExecutable Attribute is server specific. It is assumed that all Methods can be executed by at least one user. |
OPC 10000-3 differentiates between different kinds of Structures. The following conventions explain how these Structures shall be defined.
The first kind is Structures without optional fields, where none of the fields allow subtypes (except fields with abstract DataTypes). This is defined in Table 12.
Table 12 – Structures Without Optional Fields Where None of the Fields Allow Subtypes
Name |
Type |
Description |
<someStructure> |
structure |
Subtype of <someParentStructure> defined in … |
SP1 |
0:Byte[] |
Setpoint 1 |
SP2 |
0:Byte[] |
Setpoint 2 |
The second kind is Structures with optional fields, where none of the fields allow subtypes (except fields with abstract DataTypes). This is defined in Table 13.
Structures with fields that are optional have an “Optional” column. Fields that are optional have “True” set, otherwise “False”.
Table 13 – Structures with Optional Fields
Name |
Type |
Description |
Optional |
<someStructure> |
structure |
Subtype of <someParentStructure> defined in … |
|
SP1 |
0:Byte[] |
Setpoint 1 |
False |
Optional Field_1 |
0:String |
Some Text |
True |
The third kind is Structures without optional fields, where one or more of the fields allow subtypes. This is defined in Table 14.
Structures with fields that allow subtypes have an “Allow Subtypes” column. Fields that allow subtypes have “True” set, otherwise “False”. Fields with abstract DataTypes can always have subtypes.
Table 14 – Structures Where One or More of the Fields Allow Subtypes
Name |
Type |
Description |
AllowSubtypes |
<someStructure> |
structure |
Subtype of <someParentStructure> defined in … |
|
SP1 |
0:Byte[] |
Setpoint 1 |
False |
Allow Subtypes |
0:ByteString |
Some Bytestring |
True |