1、IEC/ISO-1-d1346_2A.doc,printed:1997-09-01INTERNATIONAL ELECTROTECHNICAL COMMISSION_2CD of IEC 61346-2after meeting in Oberhausen1997-07-01Structuring principles and reference designationPart 2:Classification of objects and codes for classesIEC/ISO-2-CONTENTSPageFOREWORD.3INTRODUCTION.3Clause1Scope.4
2、2Normative references.43Definitions.44Classification principle.55Classification of objects according to purpose or task.56Classification of infrastructur objects.117Sub-classes.138Application of classes and sub-classes.13Annex A.15Annex B.17Annex C.19IEC/ISO-3-INTERNATIONAL ELECTROTECHNICAL COMMISSI
3、ON_INDUSTRIAL SYSTEMS,INSTALLATIONS AND EQUIPMENTAND INDUSTRIAL PRODUCTS STRUCTURING PRINCIPLES AND REFERENCE DESIGNATIONS Part 2:Classification of objects and codes for classes_ForewordThis draft of International Standard IEC 61346-2 has been prepared by subcommittee 3B:Documentation,of IEC technic
4、al committee 3:Documentation and graphical symbols,and ISOtechnical committee 10:Technical drawings,product definitions and related documentation.IEC 61346 consists of the following parts under the general title:Structuring principles and referencedesignations:Part 1:Basic rules Part 2:Classificatio
5、n of objects and codes for classes Part 3:Application guidelines(under consideration)Part 4:Discussion of some concepts used in the reference designation system(technical report)Introduction(to this draft)IEC 61346-2 is based on the basic requirements published as 3B(Secretariat)123 within IEC andTC
6、10 N575 within ISO,and the comments received and published as 3B(Secretariat)140.Therevised basic requirements are presented in the informative annex A.The first draft was distributed as 3B/195/CD within IEC and as TC10,N655 within ISO.Commentswere received and distributed as 3B/213/CC.Annex B(infor
7、mative)illustrates,how objects may be classified according to their purpose related toa process.Annex C shows an excerpt of the table from ISO/DIS 14617-6.In the first draft a new classificationscheme was presented using to a great extent the same letter codes as in the ISO draft.This led tosome con
8、fusion.The working group decided,to delete that table and refer to the ISO-documentalthough it shows no classification scheme but qualifying symbols.This may lead to unsufficientcovering of the needs in some fields of application.Especially electric variables are represented byone letter only.It was
9、 however seen that in most cases the variables will only be dealt with astechnical attributes or also as part of the graphical symbol.The aim of IEC 61346-2 is to establish classification schemes for objects which can be appliedthroughout all technical areas.Therefore existing letter codes,like thos
10、e from the former IEC 750(see IEC 61346-1,annex E),have been included unless they interfere with a generic approach.It washowever tried to find a solution which will cause as few changes as possible.IEC/ISO-4-INDUSTRIAL SYSTEMS,INSTALLATIONS AND EQUIPMENTAND INDUSTRIAL PRODUCTS STRUCTURING PRINCIPLE
11、S AND REFERENCE DESIGNATIONS Part 2:Classification of objects and codes for classes1 ScopeThis part of IEC 61346 establishes object classes and associated letter codes for these classes.Theletter codes are intended to be used in reference designations.The classification schemes are applicable for ob
12、jects in all technical areas and may be applied at anylevel in a hierarchical structure set up in accordance with IEC 61346-1.2 Normative referencesThe following normative documents contain provisions which,through reference in this text,constituteprovisions of this part of IEC 61346.At the time of
13、publication,the editions indicated were valid.Allnormative documents are subject to revision,and parties to agreements based on this part of IEC61346 are encouraged to investigate the possibility of applying the most recent editions of thenormative documents indicated below.Members of IEC and ISO ma
14、intain registers of currently validInternational Standards.IEC 61346-1:1996,Industrial systems,installations and equipment and industrial products Structuring principles andreference designations Part 1:Basic rulesISO/DIS 14617-6,Graphical symbols for diagrams Part 6:Measurement and control function
15、s3 DefinitionsFor the purpose of this part of IEC 61346,the definitions given in part 1 apply.IEC/ISO-5-4 Classification principleThe principle of classification of objects is based on viewing each object as being part of a processwith input and output(see figure 1).objectinputoutputprocessFigure 1
16、The basic process conceptEach object being part of a process can be characterized by the purpose or task with respect to itsinput and output.This implies that it is of no importance how the object is built-up internally.Purposeand task are the main characteristics for establishing a classification scheme in this InternationalStandard.(See also annex B.)5 Classification of objects according to purpose or taskIf at any level in any hierarchical structure an object is relevant from the view how thi
