This structure contains a label and an ID describing a chemical substance. The structure is defined in Table 219.

Table 219 – ChemicalSubstanceDataType Structure

Name

Type

Description

Allow Subtypes

ChemicalSubstanceDataType

structure

Subtype of 0:Structure type defined in OPC 10000-3

PatDictionary

PatDictionaryEnum

PatDictionary

True

Label

0:LocalizedText

Label

True

Id

0:LocalizedText

ID

True

PatDictionary: identifier that determines the type of information given by the Id. It can obtain the following values given by its DataType PatDictionaryEnum:

  • 0 (CAS): the Id is a CAS Registry Number for a chemical substance defined in the CAS Registry by the Chemical Abstracts Service
  • 1 (PAT): the Id is a term that describes a measurand or matrix component related to a PAT device, that doesn’t have a CAS number. PAT terms are defined in IEC CDD.
  • 2 (user-defined): the Id is a term without definition. It is applied when neither CAS nor PAT terms match the measurement task.

Id: defined identification term that enables machine readability and comparability.

Label: non-defined descriptive term for the measurand or matrix. It can be adapted to the preferences and needs of manufacturers and users to achieve a common sense understanding of the measuring task.

Example: PatDictionary = 0 (CAS), Label = “O2”, Id = “7782-44-7”. This identifies oxygen.

Its representation in the AddressSpace is defined in Table 220.

Table 220 – ChemicalSubstanceDataType definition

Attribute

Value

BrowseName

ChemicalSubstanceDataType

IsAbstract

False

References

NodeClass

BrowseName

DataType

TypeDefinition

Other

Subtype of the 0:Structure type defined in OPC 10000-3

Conformance Units

PA-DIM PatMeasurementVariableType

PA-DIM PatMeasurementVariableType PatMatrixDescription