ISA-95 Common Object Model - 7 ISA-95 Base Information Model

Figure 19 illustrates overview of the ISA-95 Base Information Model.

Figure 19 - ISA-95 Base Information Model Overview

The test specification is a definition of a test to ensure the requirements of the ISA95Objects. The test specification may be associated with a subtype of ISA95Class, ISA95ClassProperty, ISA95Object, or ISA95Property.

The test specification is represented as Object and doesn’t define elements that represent contents of the test specification. Thus, third party shall create a subtype of the test specification to describe particular test specification (see Figure 20).

Figure 20 - Test Specification Information

For example, the subtype of test specification might have an Object of FileType (defined in OPC 10000-5) that indicates a file for the document that describes a test specification. If a test specification is stored as a file. This type is sub-typed as part of the individual data models to allow easy identification of the type of test specification being referenced, i.e. Equipment Test specification or Physical Asset test specification. It is envisioned that implementers of ISA-95 Models would create subtypes of the data model specific test specification.

7.3 Test Result Information

The test result is the result from an execution of a test specification. An ISA95Property may have a variable that provides the test result. These test results could be time series data that would be accessed by standard Attribute Services as defined in OPC UA Part4.

The test result is represented as DataVariable. The DataType of the VariableType is a structure that represents the various elements of the test result. (See Figure 21 for an example).

Figure 21 - Test Result Information

The test results listed in the figure are a minimum set of information that all test result shall include, but individual systems may provide their own structure that includes additional information. For example some systems may require the name of the person that conducted the test and the qualification that the person had. A new structure can be created that includes all of the original items along with a field for the person information and a field for the person’s qualifications. The new record can then be used for the test results.

7.4 DataTypes

7.4.1 ISA95EquipmentElementLevelEnum

This DataType is an enumeration that defines the equipment element levels defined in ISA-95. Its values are defined in a below table.

Note: for enumeration DataTypes it is recommended that variables that use the enumeration also expose the EnumStrings property. This property allows a client to easily translate the enumeration (integer value) to a string for display (see OPC 10000-3).

Table 36 – ISA95EquipmentElementLevelEnum Values

Value	Description
ENTERPRISE_0	An enterprise is a collection of sites and areas and represents the top level of a role based equipment hierarchy.
SITE_1	A site is a physical, geographical, or logical grouping determined by the enterprise. It may contain areas, production lines, process cells, and production units.
AREA_2	An area is a physical, geographical, or logical grouping determined by the site. It may contain work centres such as process cells, production units, production lines, and storage zones.
PROCESSCELL_3	Process cells are the low level of equipment typically scheduled by the Level 4 and Level 3 functions for batch manufacturing processes. The definitions for process cells are contained in IEC 61512-1.
UNIT_4	Units are low level of equipment typically scheduled by the Level 4 and Level 3 functions for batch manufacturing processes and continuous manufacturing processes. The definition of the unit for batch manufacturing processes is contained in IEC 61512-1.
PRODUCTIONLINE_5	Production lines are low levels of equipment typically scheduled by the Level 4 or Level 3 functions for discrete manufacturing processes.
WORKCELL_6	Work cells are low levels of equipment typically scheduled by the Level 4 or Level 3 functions for discrete manufacturing processes.
PRODUCTIONUINT_7	Production units are the lowest level of equipment typically scheduled by the Level 4 or Level 3 functions for continuous manufacturing processes.
STORAGEZONE_8	Storage zones are low level of material movement equipment typically scheduled by the Level 4 and Level 3 functions for discrete, batch and continuous manufacturing processes.
STORAGEUNIT_9	Storage units are low level of material movement equipment typically scheduled by the Level 4 and Level 3 functions for discrete, batch and continuous manufacturing processes.
WORKCENTER_10	Work centres are typically the grouping of equipment scheduled by the Level 4 or Level 3 functions.
WORKUNIT_11	A work unit is any element of the equipment hierarchy under a work centre. Work units are the lowest form of elements in an equipment hierarchy that are typically scheduled by Level 3 functions.
EQUIPMENTMODULE_12	An equipment module entity is an engineered subdivision of a process cell, a unit, or another equipment module. The definition of the equipment module is contained in IEC 61512-1.
CONTROLMODULE_13	A control module entity is an engineered subdivision of a process cell, a unit, an equipment module, or another control module. The definition of the equipment module is contained in IEC 61512-1.
OTHER_14	The types of work centres may be extended when required for application specific role based equipment hierarchies where the defined types do not apply. In that case, the equipment element level shall be specified as this value, and actual value that identifies the level shall be specified by OtherValue Property of ISAHierarchyScopeType defined in 7.4.1. When a new type is added it shall maintain the same relationship within the hierarchy as the defined work centre types (within an area and contains work units).

Its representation in the OPC UA AddressSpace is defined in a below table.

Table 37 – ISA95EquipmentElementLevelEnum Definition

Attributes	Value
BrowseName	ISA95EquipmentElementLevelEnum

7.4.2 ISA95TestResultMeasurementDataType

This structure contains elements that records the result from the execution of a test identified in a Test Specification.

Table 38 – ISA95TestResultMeasurementDataType Structure

Name	Type	Description
ISA95TestResultMeasurementDataType	Structure	Information that describes the test record.
Id	NodeId	Identification associated with the test result.
TestResultDescription	LocalizedText	Additional information or description about the result.
Date	DateTime	Date and time of the test. (may be different then Time stamp of the value – which would be when it was recorded)
Result	BaseDataType	The result of qualification test.
ResultUnitOfMeasure	EUInformation	The unit of measure of the associated test result.
Expiration	DateTime	The date of the expiration of the test result.

Its representation in the AddressSpace is defined in a below table.

Table 39 – ISA95TestResultMeasurementDataType Definition

Attributes	Value
BrowseName	ISA95TestResultMeasurementDataType

7.4.3 ISA95TestResultDataType

This structure contains elements that records the result from the execution of a test identified in a Test Specification. This data type shall be the default DataType for test results.

Table 40 – ISA95TestResultDataType Structure

Name	Type	Description
ISA95TestResultDataType	Structure	Information that describes the test record.
Id	NodeId	Identification associated with the test result.
TestResultDescription	LocalizedText	Additional information or description about the result.
Date	DateTime	Date and time of the test. (may be different then Time stamp of the value – which would be when it was recorded)
Result	BaseDataType	The result of qualification test.
ResultUnitOfMeasure	String	The unit of measure of the associated test result.
Expiration	DateTime	The date of the expiration of the test result.

Its representation in the AddressSpace is defined in a below table.

Table 41 – ISA95TestResultDataType Definition

Attributes	Value
BrowseName	ISA95TestResultDataType

7.5 VariableTypes

7.5.1 Overview

The section defines common variable types that are used by multiple section of the ISA specification (i.e. equipment and physical assets etc.) In some cases these types define a generic version of the variable that will be further customized in the specific section, i.e. equipment or physical asset variable section.

The variable types defined in the following sections make use of reference types that are defined in section 9. These reference types provide specific semantic information. To fully understand the Variable or Object models it may be required to review these reference descriptions.

7.5.2 ISA95ClassPropertyType

The ISA95ClassPropertyType is an abstract VariableType that cannot be used directly. It must be subtyped to be used. It is a subtype of BaseDataVariableType defined in OPC 10000-5.

This VariableType is used to define an ISA95ClassProperty for an ISA95Class.

Table 42 – ISA95ClassPropertyType definition

Attribute	Value
BrowseName	ISA95ClassPropertyType
IsAbstract	True
ValueRank	0 (OneOrMoreDimensions)
DataType	BaseDataType
References		NodeClass	BrowseName	DataType	TypeDefinition	ModellingRule
Subtype of the BaseDataVariableType defined in OPC 10000-5
HasISA95Attribute		Variable	Key	CDTIdentifier	BaseDataVariableType	Optional

The Key defines an Id to differentiate between the different values. When multiple values are stored to the Value attribute this ISA95Attribute is used. For example a value may be a series of numbers, such as a series of peak values from a spectrometer.

7.5.3 ISA95PropertyType

The ISA95PropertyType is an abstract VariableType that cannot be used directly. It must be subtyped to be used. It is a subtype of BaseDataVariableType defined in OPC 10000-5.

This VariableType is used to define an ISA95Property for an ISA95Object.

Table 43 – ISA95PropertyType definition

Attribute	Value
BrowseName	ISA95PropertyType
IsAbstract	True
ValueRank	0 (OneOrMoreDimensions)
DataType	BaseDataType
References		NodeClass	BrowseName	DataType	TypeDefinition	ModellingRule
Subtype of the BaseDataVariableType defined in OPC 10000-5
HasISA95Attribute		Variable	Key	CDTIdentifier	BaseDataVariableType	Optional

Key defines an Id to differentiate between the different values. When multiple values are stored to Value attribute this ISA95Attribute is used. For example a value may be a series of numbers, such as a series of peak values from spectrometer.

7.5.4 ISA95TestResultType

The ISA95TestResultdType is a concrete VariableType that can be used directly. It is a subtype of BaseDataVariableType defined in OPC 10000-5.

This VariableType indicates the test results. Value attribute of this DataVariable is structured data. However, each element of the structure can be accessed via Properties.

Table 44 – ISA95TestResultType definition

Attribute	Value
BrowseName	ISA95TestResultType
IsAbstract	False
ValueRank	0 (OneOrMoreDimensions)
DataType	Structure
Historizing	True
References		NodeClass	BrowseName	DataType	TypeDefinition	ModellingRule
Subtype of the BaseDataVariableType defined in OPC 10000-5
HasISA95Attribute		Variable	Id	NodeId	PropertyType	Mandatory
HasISA95Attribute		Variable	ResultDescription	LocalizedText	PropertyType	Mandatory
HasISA95Attribute		Variable	TestDate	DateTime	PropertyType	Mandatory
HasISA95Attribute		Variable	Result	BaseDataType	PropertyType	Mandatory
HasISA95Attribute		Variable	ResultUnitOfMeasure	BaseDataType	PropertyType	Mandatory
HasISA95Attribute		Variable	Expiration	DateTime	PropertyType	Mandatory

Note: The Variable has a DataType of Structure which is generic and must be assigned to a defined sub-type before it is transmitted on the wire. The generic Structure DataType results in an ExtensionObject being placed on the wire. The default defined sub-type is either ISA95TestResultDataType or ISA95TestResultMeasurementDataType depending on the nature of the data. If a different structure is used, it shall include all of the fields defined in this structure and the defined sub-type of this variable type shall also include any additional fields that are in the structure as separate variables.

Id is an identifier of the Test Result. This field can be used to reference the actual result.

ResultDescription is an additional information or description of the test result.

TestDate is the date and time of the test. This Time is used to determine when a test expires, it is server specific as to whether it is a test start time or end time, but it should be consistent in all cases.

Result is the result of the test (further defined in subtypes).

ResultUnitOfMeasure is the unit of measure of the associated test result. It is defined as a structure to allow either a EUInformation or a measurement code (clause 6.3.8) to be reported.

Expiration is the date of the expiration of the test result.

7.6 ObjectType

7.6.1 Overview

The section defines common object types that are used by multiple section of the ISA specification (i.e. equipment and physical assets etc.) In some cases these types define a generic version of the object that will be further customized in the specific section, i.e. equipment or physical asset variable section.

The object types defined in the following sections make use of reference types that are defined in section 9. These reference types provide specific semantic information. To fully understand the Object models it may be required to review these reference descriptions.

7.6.2 ISA95ClassType

The ISA95ClassType is an abstract ObjectType that cannot be used directly. It is a subtype of BaseObjectType defined in OPC 10000-5.

This abstract ObjectType is used to define groupings of functionality that is associated with an ISA95Object. AnyISA95Object may be associated with zero or more ISA95Classes.

Objects of this ObjectType or its subtypes may be associated to ISA95TestSpecifications or their subtypes.

Table 45 - ISA95ClassType definition

Attribute		Value
BrowseName		ISA95ClassType
IsAbstract		True
References	NodeClass		BrowseName	DataType	TypeDefinition	ModellingRule
Subtype of the BaseObjectType defined in OPC 10000-5

7.6.3 ISA95ObjectType

The ISA95ObjectType is an abstract ObjectType that cannot be used directly. It is a subtype of BaseObjectType defined in OPC 10000-5.

Table 46 - ISA95ObjectType definition

Attribute		Value
BrowseName		ISA95ObjectType
IsAbstract		True
References	NodeClass		BrowseName	DataType	TypeDefinition	ModellingRule
Subtype of the BaseObjectType defined in OPC 10000-5

7.6.4 ISA95TestSpecificationType

The ISA95TestSpecificationType is an abstract ObjectType that cannot be used directly. It is a subtype of BaseObjectType defined in OPC 10000-5.

This ObjectType is a base ObjectType that has no elements that describe the test specification, it is expected that sub types of this ObjectType will be created by implementers of this standard and will define the details associated with a test specification. This ObjectType indicates the existence of a test specification. This is typically used where a test is required to ensure capability of a modelling target such as ISA95Person.

Table 47 - ISA95TestSpecificationType definition

Attribute		Value
BrowseName		ISA95TestSpecificationType
IsAbstract		True
References	NodeClass		BrowseName	DataType	TypeDefinition	ModellingRule
Subtype of the BaseObjectType defined in OPC 10000-5
HasISA95Attribute	Variable		Version	String	BaseDataVariableType

Version is a version of the test specification.