1、29C.D.U./U.D.C.:621.3:001.5.004.5(035.5)744.423COMMISSION ELECTROTECHNIQUE INTERNATIONALENORME DE LA CEIINTERNATIONAL ELECTROTECHNICAL COMMISSIONIEC STANDARDPublication 113-8Premiere edition-First edition1982Schemas,diagrammes,tableauxHuitieme partie:Etablissement des schmas pour manuels des instruc
2、tions fonctionnellesDiagrams,charts,tablesPart 8:Preparation of diagrams for system manualsMots cles:manuel dentretien pour systemes;Key words:system maintenance manual;schemas.diagrams.CCEI 1982Droits de reproduction reserves-Copyright-all rights reservedAucune partie de cette pubication ne peut tr
3、e reproduite ni utilisle sous No part of this publication may be reproduced or utilized in anyqueique forme que ce soit et par aucun procde,lectronique ou mca-form or by any means,electronic or mechanical,including photocopyingnique,y compris la photocopie et les microfilms,sans Iaccord orit de Idit
4、eur.I and miorofilm,without permission in writing from the publisher.Bureau Central de la Commission Electrotechnique Internationale3,rue de VarembeGeneve,SuisseIECPrixFrs.75.-PriceVoL.to113-8IEC198295.Functional system documentation5.1 ObjectivesSystem manuals seek to present information in ways wh
5、ich clarify the working of a system andhence facilitate the tasks of training and maintenance.With complex systems the location offaults often takes a longer time than their repair and it is therefore important that the docu-mentation should be laid out in a way which best aids the diagnostic proces
6、s.Functional systemdocumentation meets this objective by presenting information at a number of arbitrarily chosenlevels corresponding to functional rather than physical sub-divisions of the system.5.2 The concept of functionalizationIn this context,a function may be defined as an operation or proces
7、s which has a definiteeffect on signal or logic flow and hence on system behaviour.Functional flow describes thelogical interworking of equipment functions which enables an equipment to achieve its purpose.It is a prime objective of functionally based documentation to capture this functional flow wh
8、ichis often masked by hardware boundaries.Thus circuit diagrams are often prepared for discreteitems of equipment such as printed wiring boards or sub-assemblies.A functionally based diagram,however,will often group hardware items located in different parts of an equipment provided theyact together
9、to perform an identifiable function.5.3 Presentation of dataData is provided at a number of levels determined by functional analysis of the equipment orsystem covered by the documentation.Coverage progresses from the most general to the mostparticular,the information at each level being functionally
10、 and logically related to that at thepreceding level.The number of levels provided depends on the factors mentioned in the secondparagraph of Clause 4 and on the size chosen for the diagrams.6.Preparation of diagrams for system manuals6.1 General principlesIn order to meet the objectives outlined in
11、 Sub-clause 5.1,diagrams should be prepared inaccordance with the following aims and principles.6.1.1 Fitness for purposeEach diagram should be prepared with its primary purpose in mind.Different considerations will apply to diagrams prepared for general explanatory purposes thanwill apply to those
12、prepared specially for use by maintenance personnel.The former need onlyprovide a clear explanation of how the equipment works whereas the latter should also includeall the information required to locate and clear faults(see Sub-clause 6.1.5).6.1.2 Functional layoutClause 5 has explained that functional system documentation generally takes the form of astructural hierarchy of diagrams starting with one covering a complete system or equipment
