1、BRITISH STANDARD GRAFCET specification language for sequential function charts The European Standard EN 60848:2002 has the status of a British Standard ICs 29.020 BS EN 60848:2002 WkNb A%“ U- rn% E rn NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW $ present to the responsible
2、 international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. - A list of organizations represented on this committee can be obtained on reques
3、t to its secretary. From 1 January 1997, all IEC publications have the number 60000 added to the old number. For instance, IEC 27-1 has been renumbered as IEC 60027-1. For a period oftime during the change over from one numbering system to the other, publications may contain identifiers from both sy
4、stems. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standard
5、s Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not ofitself confer immunity from legal obligations. Summary of pages T
6、his document comprises a front cover, an inside front cover, the EN title page, pages 2 to 52, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. O BSI 27 May 2002 ISBN O 580 39757 2 EUROPEAN STANDARD NORME EUROP .ENN
7、E EUROPfISCHE NORM EN 60848 April 2002 ICs 29.020 English version GRAFCET specification language for sequential function charts (IEC 60848:2002) Langage de spcification GRAFCET pour diagrammes fonctionnels en squence (CE1 60848:2002) (IEC 60848:2002) Entwutfssprache GRAFCET far Ablauf-Funktionspl%m
8、This European Standard was approved by CENELEC on 2002-04-01. CENELEC members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical r
9、eferences concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENEL
10、EC member into its own language and notified to the Central Secretariat has the same status as the oficial versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta
11、, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique EuropYkches Komitee f, r Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussel
12、s O 2002 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60848:2002 E Page 2 EN 60848:2002 Foreword The text of document 3B/344/FDIS, future edition 2 of IEC 60848, prepared by SC 3B, Documentation, of IEC TC 3, Information struct
13、ures, documentation and graphical symbols, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60848 on 2002-04-01. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard or by
14、endorsement latest date by which the national standards conflicting with the EN have to be withdrawn (dop) 2003-01-01 (dow) 2005-04-01 Annexes designated “normative“ are part of the body of the standard. Annexes designated “informative“ are given for information only. In this standard, annex ZA is n
15、ormative and annexes A, B and C are informative. Annex ZA has been added by CENELEC. Endorsement notice The text of the International Standard IEC60848:2002 was approved by CENELEC as a European Standard without any modification. In the official version, for Bibliography, the following note has to b
16、e added for the standard indicated: IEC 61131-3 NOTE Harmonized as EN 61131-3:1993 (not modified) O BSI 27 May 2002 Page 3 EN 60848:2002 CONTENTS INTRODUCTION . 4 Scope and object . . 5 Normative references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 Terms and definitions . 5 . General principles 7 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 GRAFCET, a behaviour specification language GRAFCET, short presentation Evolution rules Comparison bet
18、ween the two output modes Graphical representation of the elements 16 Graphical representation of sequential structures 29 6.1 Basic structures . 29 6.2 Particular structures 32 Structuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 7.1 Partition of a grafcet 35 7.2 Structuring using the forcing of a partial grafcet . 37 7.3 Structuring using the enclosure 38 7.4 Structuring using the macro-steps 41 Annex A (i
20、nformative) Example of control of a press . 42 Annex B (informative) Example: Automatic weighing-mixing 43 Annex C (informative) Relations between the GRAFCET of IEC 60848 and the SFC of IEC 61131-3 49 Annex ZA (normative) Normative references to international publications with their corresponding E
21、uropean publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52 Bibliography 51 O BSI 27 May 2002 Page 4 EN 60848:2002 INTRODUCTION The main reason for the revision of this standard
22、 is the desire of the users to increase the standardised specification language with new concepts, allowing a structured and hierarchical description. Otherwise, in addition to the descriptive and functional aspects of the first edition, it now seems necessary to add the formal and behavioural aspec
23、ts, which are essential for the definition of a real specification language. For all these reasons, an overall review of the document is required. This standard is mainly for people (design engineers, realisation engineers, maintenance engineers, etc.) who need to specify the behaviour of a system (
24、control-command of an automatic machine, safety component, etc.). This specification language should also serve as a communication means between designers and users of automated systems. O BSI 27 May 2002 Page 5 EN 60848:2002 GRAFCET SPECIFICATION LANGUAGE FOR SEQUENTIAL FUNCTION CHARTS 1 Scope and
25、object This International Standard defines the GRAFCETI) specification language for the functional description of the behaviour of the sequential part of a control system. This standard specifies the symbols and the rules for the graphical representation of this language, as well as for its interpre
26、tation. This standard has been prepared for automated production systems of industrial applications. However no particular area of application is excluded. Methods of development of a specification that makes use of GRAFCET are beyond the scope of this standard. One method is for example the “SFC la
27、nguage“ specified in IEC 61131-3, which defines a set of programming languages for programmable controllers. NOTE such as the SFC of IEC 61131-3. See annex C for further information on the relations between IEC 60848 and implementation languages 2 Normative references The following normative documen
28、ts contain provisions, which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encoura
29、ged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of IEC and IS0 maintain registers of currently valid International Standards. IEC 6005
30、0-351 :I 998, Infernafional Elecfrofechnical Vocabulary (VE1 - Parf 351: Aufomafic confrol IEC 60617-12:1997, Graphical symbols for diagrams - Parf 12: Binary logical elemenfs 3 Terms and definitions For the purposes of this International Standard, the following definitions apply. The definitions of
31、 the terms preceded by an asterisk apply only in the context of the GRAFCET specification language. The chosen order is the alphabetic one. 3.1 * action GRAFCET language element associated with a step, indicating an activity to be performed on out put variables 1) GRAFCET , GRAphe Fonctionnel de Com
32、mande Etape Transition O BSI 27 May 2002 Page 6 EN 60848:2002 3.2 chart, graph graphical presentation describing the behaviour of a system, for example the relations between two or more variable quantities, operations or states 3.3 * directed link GRAFCET language element indicating the evolution pa
33、ths between steps by connecting steps to transitions and transitions to steps 3.4 * grafcet chart function chart using GRAFCET NOTE The “grafcet chart” can, in short form, be called “grafcet” 3.5 * input event event characterized by the change of at least one value of all input variables of the sequ
34、ential part of the system 3.6 * internal event event characterized by an input event associated with the situation of the sequential part of the system 3.7 * interpretation part of the GRAFCET enabling the linkage of: - the input variables and the structure, by the means of the transition-condition;
35、 - the output variables and the structure, by the means of the actions 3.8 * situation name of the state of the system described by grafcet and characterised by the active steps at a given instant 3.9 * step GRAFCET language element used for the definition of the state of the sequential part of the
36、system NOTE 1 A step can be active or inactive. NOTE 2 The set of active steps represents the situation of the system. 3.10 * structure part of the GRAFCET enabling the description of the possible evolution between situations 3.11 system a set of interrelated elements considered in a defined context
37、 as a whole and separated from their environment IEV 351-11-01 NOTE 1 mathematical methods, programming languages). Such elements may be material objects and concepts as well as their results (e.g. forms of organisation, O BSI 27 May 2002 Page 7 EN 60848:2002 NOTE 2 The system is considered to be se
38、parated from the environment and from the other external systems by an imaginary surface, which cuts the links between them and the system. NOTE 3 The language GRAFCET can be use to describe the logical behaviour of any kind of system 3.12 * transient evolution evolution characterized by the clearin
39、g of several successive transitions on the occurrence of a single input event 3.13 * transition GRAFCET language element indicating a possible evolution of the activity between two or more steps NOTE The possible evolution is realised by clearing the transition. 3.14 * trans it ion-co nd i t io n GR
40、AFCET language element associated with a transition indicating the result of a boolean expression NOTE The transition-condition can be either true or false. 4 General principles 4.1 Context The implementation of an automated system requires, in particular, a description relating cause and effect. To
41、 do this, the logical aspect of the desired behaviour of the system will be described. The sequential part of the system, which is accessed via Boolean input and output variables, is the logical aspect of this physical system. The behaviour indicates the way in which the output variables depend on t
42、he input variables (see note to figure 1). The object of the GRAFCET is to specify the behaviour of the sequential part of the systems. A SYSTEM I SEQUENTIAL PART OF THE SYSTEM fi I b Il auto b P/P Boolean inputs b DCY J Pv b /: Test Non boolean- b I P= (auto . Pv ) + (P/P . Dcy) NOTE The sequential
43、 part of the system is characterised by its input variables, its output variables, and its behaviour. This sequential part comprises only input and output boolean variables. However the GRAFCET specification language by extension allows the description of the behaviour of the non Boolean variables (
44、for example: evaluation of an assertion or allocation of a numeric value for a variable). Figure 1 - Graphical representation of the sequential part of a system O BSI 27 May 2002 Page 8 EN 60848:2002 4.2 GRAFCET, a behaviour specification language The GRAFCET specification language enables a grafcet
45、 to be created showing the expected behaviour of a given sequential system. This language is characterized mainly by its graphic elements, which, associated with an alphanumerical expression of variables, provides a synthetic representation of the behaviour, based on an indirect description of the s
46、ituation of the system. The behaviour description on states is the following: the “monomarked“ states correspond to the GRAFCET sifuafions, which implies the uniqueness of the situation at a given instant. The states are connected to each other by means of an evolution condition, which allows the pa
47、ssage from one situation to another one to be described. For reasons of convenience, the behaviour description based on states is better replaced by a description based on sfeps called GRAFCET. In the GRAFCET, several steps may be active simultaneously, the situation being then characterized by the
48、set of active steps at the considered moment. The evolution of one set of steps to another are translated by one or several transitions, each characterized by: 0 its preceding steps, 0 its succeeding steps, 0 its associated transition-condition NOTE These reasons lead to the syntax rule enforcing th
49、e alternation step-transition. 4.3 GRAFCET, short presentation The GRAFCET is used for the design of grafcet charts to provide a graphical and synthetic representation of the sequential systems behaviour. The representation (figure 2) distinguishes: 0 0 the sfrucfure, which allows possible evolutions between the situations to be described, the inferprefafion, which enables the relationship between input, output variables and the structure (evolution, assignation and allocation rules are necessary to achieve this interpretation). 4.3.1 0 The structure comprises th
