BS EN 1922-1998 Information technology Character repertoire and coding for interworking with Telex services《信息技术 远程服务配合字符指令和编码》.pdf

1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 1922 : 1998 The Eur

2、opean Standard EN 1922 : 1997 has the status of a British Standard ICS 35.040 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Information technology Character repertoire and coding for interworking with Telex servicesThis British Standard, having been prepared under the direct

3、ion of the DISC Board, was published under the authority of the Standards Board and comes into effect on 15 February 1998 BSI 1998 ISBN 0 580 28883 8 BS EN 1922 : 1998 Amendments issued since publication Amd. No. Date Text affected National foreword This British Standard is the English language vers

4、ion of EN 1922 : 1997. It supersedes DD ENV 41504 : 1991 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee IST/2, Character Sets and Information Coding, which has the responsibility to: aid enquirers to understand the text; present to the responsible Eu

5、ropean 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 request to its secretary.

6、 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 Standards Electron

7、ic Catalogue. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 6, an inside back cover and a back cover.CEN European Committee for Standardization

8、 Comite Europe en de Normalisation Europa isches Komitee fu r Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1997 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1922 : 1997 E EUROPEAN STANDARD EN 1922 NORME EUROP

9、E ENNE EUROPA ISCHE NORM September 1997 ICS 35.040.70; 35.040 Descriptors: Data processing, teleprocessing, information interchange, data transmission, telex, coded character sets, directories, codification English version Information technology Character repertoire and coding for interworking with

10、Telex services Technologies de linformation Re pertoire des caracte res et codage pour linteraction avec les services te lex Informationstechnik Zeichenvorrat und Codierung fu r die Zusammenarbeit mit Telex-Diensten This European Standard was approved by CEN on 15 August 1997. CEN members are bound

11、to comply with the CEN/CENELEC 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 references concerning such national standards may be obtained on application to the Cent

12、ral Secretariat or to any CEN 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 CEN member into its own language and notified to the Central Secretariat has the same status as

13、the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.Page 2 EN 1922 : 1997 BSI 1998 Forewo

14、rd This European Standard has been prepared by Technical Committee CEN/TC 304, Character Set Technology, the secretariat of which is held by STRI. This European Standard supersedes ENV 41504 : 1990 (drawn up by CEN/CENELEC/IT/ WG-CSC). This European Standard shall be given the status of a national s

15、tandard, either by publication of an identical text or by endorsement, at the latest by March 1998, and conflicting national standards shall be withdrawn at the latest by March 1998. This standard is available in English and German only. According to the CEN/CENELEC Internal Regulations, the nationa

16、l standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Cont

17、ents Page Foreword 2 1 Scope 3 2 Normative references 3 3 Definitions 3 4 Description 3 5 Conformance 4 5.1 Conformance of information interchange 4 5.2 Conformance of devices 4 5.2.1 General 4 5.2.2 Device description 4 5.2.3 Originating devices 4 5.2.4 Receiving devices 4 6 Repertoire description

18、4 6.1 Repertoire options 4 6.2 Graphic characters 4 6.2.1 Latin graphic repertoire 4 6.2.2 Greek letter case 5 6.3 Control functions 5 7 Coding methods 5 7.1 Coding methods for Latin repertoire 5 7.2 Coding methods for Latin and Greek repertoire 5 7.3 Coding methods for control characters 5 7.4 16/3

19、2 coding environments 5 8 Identification of options 5 Annexes A (normative) Extended repertoire for national or private use 5 B (informative) Application to Latin and Greek character repertoires 5Page 3 EN 1922 : 1997 BSI 1998 1 Scope This European Standard specifies the graphic character repertoire

20、 and control functions relevant for information interchange via Telex services. It is intended to be used with and identified within other European functional standards that specify strings of coded characters for the interchange of coded information between information processing systems (IPS) via

21、Telex services. This standard specifies two alternative options for graphic character repertoires: option A for Latin graphic characters; and option B for Latin and Greek graphic characters. NOTE. The assignment of characters to three of the code positions is outside the scope of this standard. Such

22、 assignment is subject to national or private agreement. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter.

23、 For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated by amendment or revision. For undated references the latest edition of the publication referred to applies. prEN 1923 European character repertoires and th

24、eir coding 8-bit single-byte coding ISO/IEC 6429 Information technology Control functions for coded character sets ISO/IEC 8859-1 Information processing 8-bit single-byte coded graphic charactersets Part 1: Latin alphabet No. 1 ISO/IEC 8859-7 Information processing 8-bit single-byte coded graphic ch

25、aracter sets Part 7: Latin/Greek alphabet ISO/IEC 10646-1 Information technology - Universal multiple-octet coded character set (UCS) - Part 1: Architecture and basic multilingual plane ITU-T Recommendation S.1, 1993 International Telegraph Alphabet No. 2 ELOT 1095 Character set intended to be used

26、in the Hellenic Telex and telegraphic service (in Greek) 3 Definitions For the purposes of this standard the definitions given in ISO/IEC 10646-1 and the following apply. 3.1 CC-data-element An element of interchanged information that is specified to consist of sequences of coded representations of

27、characters, in accordance with one or more identified standards of coded character sets. 3.2 device A component of information processing equipment which can transmit, and/or can receive, coded information within CC-data-elements. (It may be an input/output device in the conventional sense, or a pro

28、cess such as an application program or gateway function). 3.3 user A person or other entity that invokes the services provided by a device. (This entity may be a process such as an application program if the device is a code converter or a gateway function, for example). 4 Description Within the sco

29、pe of this standard the processing of information interchange via Telex network equipment is as in figure 1. Information processing systems (IPS) work with character sets and coding in an ISO 8-bit environment, and these systems need to communicate via the international Telex service, with the restr

30、iction on coding and characters this implies. This standard defines a transformation module that will transform 8-bit CC-data-elements (IPS side) in accordance with an option of prEN 1923 into 5-bit CC-data-elements in accordance with ITU-T Recommendation S.1 (Telex side) and vice versa, while retai

31、ning as much as possible of the character repertoires functionality. This transformation module deals only with the repertoire of clause 6 of this standard, while the transformation of CC-data-elements other than those conforming to clause 6 is outside the scope of this standard. In addition, 6.2.2

32、specifies a Greek character repertoire, as in ELOT 1095. It follows from this, that the device to which conformance in accordance with 5.2 applies is the transformation module, and the user is the IPS. One transformation module may be replaced by a sending or receiving Telex terminal. NOTE. This sta

33、ndard does not describe the international Telex service. In the preparation of this standard the specification of the international Telex service was assumed to be as in ITU-T Recommendation S.1 for option A, and in ITU-T Recommendation S.1 and ELOT 1095 for option B, respectively. The use of the th

34、ree code combinations in Figure Shift in the Telex code, which have been reserved for national or private use, is outside the scope of this standard.Page 4 EN 1922 : 1997 BSI 1998 Figure 1. 5 Conformance 5.1 Conformance of information interchange A CC-data-element within coded information for interc

35、hange is in conformance with this standard if all the coded representations of characters within that CC-data-element conform to the requirements of clause 7 of this standard. A claim of conformance shall identify the option adopted as specified in clause 8. 5.2 Conformance of devices 5.2.1 General

36、A device is in conformance with this standard if it conforms to the requirements of 5.2.2, and either or both of 5.2.3 and 5.2.4. A claim of conformance shall identify the documents which contain the description specified in 5.2.2 and shall identify the option adopted. 5.2.2 Device description A dev

37、ice that conforms to this standard shall be the subject of a description that identifies the means by which the user may supply characters to the device, or may recognize them when they are made available to him, as specified respectively in 5.2.3 and 5.2.4. 5.2.3 Originating devices An originating

38、device shall allow its user to supply any sequence of characters conforming to the adopted option of this standard, and shall be capable of transmitting their coded representations within a CC-data-element. 5.2.4 Receiving devices A receiving device shall be capable of receiving and interpreting any

39、 coded representations of characters that are within a CC-data-element, and that conform to 5.1 of this standard, and shall make the corresponding characters available to its user in such a way that its user can identify them from among those of the adopted option, and can distinguish them from each

40、 other. 6 Repertoire description 6.1 Repertoire options This standard specifies the following two graphic character repertoires: option A : Latin graphic character repertoire (6.2.1); or option B : Latin and Greek graphic character repertoire (6.2.1 and 6.2.2). 6.2 Graphic characters 6.2.1 Latin gra

41、phic character repertoire The Latin graphic character repertoire consists of: the character space; the 26 Latin letters A (a) through to Z (z); the 10 digits zero through to nine; the following punctuation and miscellaneous characters: . full stop; , comma; : colon; ? question mark; apostrophe; + pl

42、us sign; - hyphen-minus; / solidus; = equals sign; ( left parenthesis; ) right parenthesis; three unidentified characters, see note 1 and annex A. In this repertoire, no distinction is made between the capital and small forms of the same letter. However, a transmitting product shall allow its user t

43、o supply any letter in either its capital or its lower case form. NOTE.1. ITU-T Recommendation S.1 contains three code combinations for which no graphic characters have been determined. The selection of these characters is left to national or regional agreement. NOTE.2. The use of extra control func

44、tions to distinguish between the capital and the small forms of the same letter is subject to national or private agreement.Page 5 EN 1922 : 1997 BSI 1998 6.2.2 Greek letter case The Greek graphic repertoire consists of the 24 (25) Greek letters alpha to omega, see Annex B. This repertoire makes no

45、distinction between the capital and lower case forms of the same letter, nor between the small Greek letter sigma and the small Greek letter terminal sigma. However, a transmitting product shall allow its user to supply any letter in either its capital or any of its lower case forms. NOTE. A special

46、 control function is provided by the Telex service to shift between Latin and Greek graphic character repertoires, see ELOT 1095. 6.3 Control functions The repertoire of control functions shall comprise the following three control functions: line feed; carriage return; bell. NOTE. The control functi

47、on WRU (Who are you?) is used only during the establishment and confirmation of a connection, which is outside the scope of this standard. 7 Coding methods 7.1 Coding methods for Latin graphic character repertoire Information received at the 5-bit side of the transformation module, which is coded in

48、 accordance with ITU-T Recommendation S.1, shall subsequently be transformed to be coded at the information processing side (8-bit side) in accordance with the G0 set of ISO/IEC 8859-1, except that the three unidentified characters mentioned in note 1 to 6.2.1 need not necessarily belong to the G0 s

49、et. After this transformation, the alphabetic characters shall all be represented either by the codes for capital letters, or by the codes for lower case letters, unless agreed otherwise by the communicating parties. Information received at the transformation module from the 8-bit side shall initially be coded in accordance with ISO/IEC 8859-1, without any restrictions on the use of lower case or capital letters. Subsequently it shall be transformed by the transformation module to be cod