3 Terms, abbreviated terms and conventions

3.1 Overview

It is assumed that basic concepts of OPC UA information modelling are understood in this document. This document will use these concepts to describe the Machine Tools Information Model. For the purposes of this document, the terms and definitions given in OPC 10000-1, OPC 10000-3, OPC 10000-4, OPC 10000-5, OPC 10000-7, OPC 10000-9, OPC 10000-20 OPC 10000-100, OPC 10000-200, OPC 10031-4, OPC 40001-1, OPC 40001-3 as well as the following apply.

Note that OPC UA terms and terms defined in this document are italicised in the document.

3.2 OPC UA for Machine Tools terms

3.2.1 Alert

3.2.2 Channel

3.2.3 Controller

3.2.4 Machine Tool

3.2.5 Manual Tool Change

3.2.6 Multitool

3.2.7 Part

3.2.8 Production Plan

list of all job elements a specific machine knows about
EXAMPLE: All jobs which were transferred to the machine in some way.

3.2.9 Untitled

3.2.10 Untitled

3.2.11 Program

also: production program; list of operations that the controller performs in sequence;
usually a machine-readable file, such as an NC program, which is needed for the controller to fulfil the job; NC programs may also carry a hierarchy of further sub-(NC)programs

3.2.12 Replacement Tool

tool with equivalent (identical) process capabilities (size and functionality) to an existing tool; used by the controller if the designated tool is locked due to wear, done automatically and/or after user interaction

3.2.13 Stacklight

3.2.14 Tool

3.2.15 Utility

3.3 Abbreviated terms

3.4 Conventions used in this document

3.4.1 Conventions for Node descriptions

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}” and the ValueRank is set to the corresponding value (see OPC 10000-3) and the ArrayDimensions is set to null or is omitted. Examples are given in Table 1.

• 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 all other 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.

Table 2 illustrates the table. 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.

Components of Nodes can be complex that is containing components by 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 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 show in Table 3.

If multiple characteristics are defined they are separated by commas. The name or the short name may be used.

3.4.2 NodeIds and BrowseNames

3.4.2.1 NodeIds

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, a “.”, and the BrowseName of itself. In this case “part of” means that the whole has a HasProperty or HasComponent Reference to its part. Since all Nodes not being 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 that some Nodes shall be generated, for example one for each Session running on the Server. The NodeIds of those Nodes are Server-specific, including the namespace. But the NamespaceIndex of those Nodes cannot be the NamespaceIndex used for the Nodes defined in this document, because they are not defined by this document but generated by the Server.

3.4.2.2 BrowseNames

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 Annex A.

If the BrowseName is not defined by this document, a namespace index prefix like ‘0:EngineeringUnits’ or ‘2:DeviceRevision’ is added to the BrowseName. This is typically necessary if a Property of another specification is overwritten or used in the OPC UA types defined in this document. Table 136 provides a list of namespaces and their indexes as used in this document.

3.4.3 Common Attributes

3.4.3.1 General

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 if 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 4 shall be set as specified in the table.

3.4.3.2 Objects

For all Objects specified in this document, the Attributes named in Table 5 shall be set as specified in the Table 5. The definitions for the Attributes can be found in OPC 10000-3.

3.4.3.3 Variables

For all Variables specified in this document, the Attributes named in Table 6 shall be set as specified in the table. The definitions for the Attributes can be found in OPC 10000-3.

3.4.3.4 VariableTypes

For all VariableTypes specified in this document, the Attributes named in Table 7 shall be set as specified in the table. The definitions for the Attributes can be found in OPC 10000-3.

3.4.3.5 Methods

For all Methods 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.