1、STD-BSI DD ENV 12925-EidGL 1998 Lb24bb b8234 DRAFT FOR DEVELOPMENT - Bar coding - Symbology specifications - PDF417 * * m ICs 35.040 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW JO4 m )D ENV 2925 : 1998 STD-BSI DD ENV 12725-ENGL 1998 1bZLibb b82398 790 = having been prepare
2、d under the direction of the DISC Board, was published under the authority of the Standards Board and comes into effect on 15 February 1998 bd. No. Q BSI 1998 ISBN O 580 29188 X DD ENV 12925 : 1998 Date Text affected National foreword This Draft for Development is the English language version of ENV
3、 12925 : 1997. This publication is not to be regarded as a British Standard. It provisional nature because the subject matter is still under development requiring wider exposure. It should be applied on this provisional basis, so that information and experience of its practid application may be obta
4、ined. Comments arising from the use of this Draft for Development are requested so that UK experience can be reported to the European organization responsible for its conversion into a European Standard. A review of this publication will be initiated 2 years after its publication by the European org
5、anization so that a decision can be taken on its status at the end of its three-year life. The commencement of the review period wiil be notified by an announcement in Update Standards. According to the replies received by the end of the review period, the responsible BSI Committee will decide wheth
6、er to support the conversion into a European Standard, to extend the life of the prestandard or to withdraw it. Comments should be sent in writing to the Secretary of BSI Technical Committee IST/34, Bar coding, at 389 Chiswick High Road, London, W4 a, giving the document reference and clause number
7、and proposing, where possible, an appropriate revision of the text. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be fou
8、nd in the BSI Standards Catalogue under the section entitled International Standards Correspondence Index, or by using the Find facility of the BSI Standards Electronic Catalogue. Compliance with a British Standard does not of itself confer immunity from legal obligations. being issued in the Draft
9、for Development series of publications and is of a Summary of pages This document comprises a front cover, an incide front cover, the ENV title page, pages 2 to 116, an inside back cover and a back cover. EUROPEAN PRESTANDARD ENV 12925 PRNORME EUROPENNE EUROPISCHE VORNORM December 1997 ICs 35.040 De
10、scriptors: data processing, character recognition, optical recognition, bar codes, symbols, specifications English version Bar coding - Symbology Specifications - PDF41 7 This European Prestandard (ENV) was approved by CEN on 17 November 1997 as a prospective standard for provisional application. Th
11、e period of validity of this ENV is limited initially to three years. Aiter two years the members of CEN will be requested to submit their comments, particularly on the question whether the ENV can be converted into a European Standard. CEN members are required to announce the existence of this ENV
12、in the same way as for an EN and to make the ENV available promptly at national level in an appropriate form. It is pennissible to keep conflicting national standards in force (in parallel to the ENV) mil the final decision about the possible conversion of the ENV into an EN is reached. CEN members
13、are the national standards bodies of Austria, Belgium, Czech Republic, Denmark. Finland, France, Gemany, Greece, Iceland, Ireland, Italy. Luxembourg, Netherlands, Norway, Portugal. Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMllTEE FOR STANDARDIZATION EUROPISCHES KOMITEE FOR NORMUNG C
14、OMITE EUROPEEN DE NORMALISATION Central Sacretariat: rue de Stassart, 36 8-1050 Brussels Q 1997 CEN All rights of exploitation in any form and by any means reserved worldwide for GEN national Members. Ref. No. ENV 12925:1997 E Page 2 ENV 12925:1997 Contents Page Foreword Introduction 1 Scope 2 Norma
15、tive References 3 3.1 Definitions 3.2 Mathematical Symbols and Operations 3.3 Abbreviations Definitions, Mathematical Symbols and Abbreviations 4 4.1 4.1.1 4.1.2 4.2 4.2.1 4.2.2 4.2.3 4.3 4.3.1 4.3.2 4.4 4.4.1 4.4.2 4.4.3 4.4.4 4.4.5 4.4.6 4.5 4.5.1 4.5.2 4.5.3 4.5.4 4.6 4.7 4.7.1 4.7.2 4.7.3 4.8 4.
16、9 4.9.1 4.9.2 4.10 4.1 1 4.1 1.1 4.1 1.2 4.1 1.3 4.11.4 4.12 Requirements Symbology Characteristics Basic Characteristics Summary of Additional Features Symbol Structure PDF41 7 Symbol Parameters Row Parameters Codeword Sequence Basic Encodation Symbol Character Structure Start and Stop Characters H
17、igh Level (Data) Encodation Function Codewords Text Compaction Mode Byte Compaction Mode Numeric Compaction Mode Advice to Select the Appropriate Compaction Mode Treatment of PDF41 7 Reserved Codewords Extended Channel Interpretation Encoding the ECI Assignment Number Pre-assigned Extended Channel I
18、nterpretations Encoding ?CI Sequences Within Compaction Modes Post-Decode Protocol Determining the Codeword Sequence Error Detection and Correction Error Correction Level Error Correction Capacity Defining the Error Correction Codewords Dimensions Defining the Symbol Format Defining the Aspect Ratio
19、 of the Module Defining the Symbol Matrix of Rows and Columns Generating the Error Correction Codewords Low Level Encodation Clusters Determining the Symbol Matrix Determining the Values of the Left and Right Row Indicators Row Encoding Compact PDF41 7 6 6 9 9 9 10 11 11 11 12 13 13 14 14 15 18 23 2
20、5 27 27 28 29 29 30 32 32 33 33 33 35 35 36 36 36 38 40 40 41 41 41 42 4.1 3 4.13.1 4.1 3.2 4.14 4.14.1 4.14.2 4.14.3 4.14.4 4.1 5 4.1 6 4.1 7 4.17.1 4.1 7.2 4.1 7.3 4.1 7.4 4.17.5 4.17.6 Annex A Annex B Annex C Annex D Annex E E. 1 E.2 Annex F Annex G Annex H H. 1 H.2 H.2.1 H.2.2 H.2.3 H.2.4 H.3 H
21、.4 H.5 H.5.1 H.5.2 H.6 H.6.1 H.6.2 H.6.3 Page 3 ENV 12925:1997 Macro PDF41 7 Compaction Modes and Macro PDF41 7 ECls and Macro PDF417 User Guidelines Human Readable Interpretation Autodiscrimination Capability User-defined Application Parameters PDF41 7 Symbol Quality Reference Decode Algorithm Erro
22、r Detection and Error Correction Procedure Transmitted Data Transmitted Data in the Basic (Default) Interpretation Transmission Protocol for Extended Channel Interpretation (ECU Transmitted Data For Macro PDF41 7 Transmission of Reserved Codewords Using the ECI Protocol Symbology Identifier Transmis
23、sion Using Older Protocols (normative) Encoding/Decoding Table of PDF41 7 Symbol Character X-Sequences (normative) The Default Character Set for Byte Compaction Mode (normative) Base 256 to Base 900 Conversion Algorithm (normative) Base 10 to Base 900 Conversion Algorithm (normative) User Selection
24、of Error Correction Recommended Error Correction Level Other User Consideration of the Error Correction Level (normative) Tables of Coefficients for Calculating PDF41 7 Error Correction Codewords (normative) Compact PDF41 7 (normative) Macro PDF417 Macro PDF41 7 Overview Macro PDF41 7 Syntax The Seg
25、ment Index File ID Field Optional Fields Macro PDF41 7 Terminator High Level Encoding Considerations Encodation Example Macro PDF41 7 and Extended Channel Interpretation Macro PDF417 with ECI O00000 and O00001 (GLI O and 1) Macro PDF41 7 and Other ECls Macro PDF41 7 Data Transmission Operating in Bu
26、ffered Mode Operating in Unbuffered Mode Reset-to-Zero Transmissions 42 42 42 43 43 43 43 44 44 44 44 44 44 45 46 46 46 47 61 62 64 66 66 66 67 72 73 73 73 74 74 74 76 76 77 78 78 78 79 80 80 81 Page 4 ENV 12925: 1997 Annex J J. 1 J.2 J.3 (normative) Testing PDF41 7 Symbol Quality Grade Based on Sta
27、rt and Stop Characters Grade Based on Symbol Characters Overall Symbol Grade 82 82 82 83 Annex K K. 1 K. 2 K.3 K.4 (normative) Reference Decode Algorithm for PDF41 7 Initialisation Reference Decode Algorithm for Line Decoding Filling the Matrix Interpretation 84 84 84 86 07 Annex L (normative) Error
28、 Correction Procedures 88 Annex M (normative) Symbology Identifier 90 Annex N (normative) Transmission Protocol for Decoders Conforming to Earlier PDF41 7 Standards Basic Channel Encodation GLI Encoded Symbols Macro PDF41 7 Symbols Transmission in Buffered Mode Transmission in Unbuffered Mode Transm
29、ission of Reserved Codewords Using the Original PDF41 7 Protocol Achieving Compatibility Between Old and New PDF41 7 Equipment Encoders Decoders 91 91 91 93 93 93 N. 1 N.2 N.3 N.3.1 N.3.2 N.4 94 N.5 95 95 95 N.5.1 N.5.2 Annex P (informative) Algorithm to Minimise the Number of Codewords 98 Annex Q (
30、informative) Autodiscrimination Compatibility 1 O0 Annex R (informative) Guidelines to Determine the Symbol Matrix 101 Annex S (informative) Calculating the Coefficients for Generating the Error Correction Codewords - Worked Example 105 Annex T (informative) Generating the Error Correction Codewords
31、 - Worked Example 106 Annex U (informative) Division Circuit Procedure for Generating Error Correction Codewords 1 o9 Annex V (informative) Bibliography 110 * ln 4 STD.BSI DD ENV 12725-ENGL L778 = lb2Libb Ob82403 738 Page 5 ENV 12925: 1997 Foreword This European Prestandard has been prepared by Tech
32、nical Committee CEN/TC 225 “Bar coding“, the secretariat of which is held by NNI. Organisations contributing to the development of the standard include: Symbol Technologies Inc (as original inventors of PDF41 7 symbology) AIM Europe (Automatic Identification Manufacturers) AIM USA (Automatic Identif
33、ication Manufacturers) According to the CENKENELEC Internal Regulations, the national standards organizations of the following countries are bound to announce this European Prestandard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg,
34、Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Introduction The technology of bar coding is based on the recognition of patterns encoded in bars and spaces of defined dimensions. There are various methods of encoding information in bar code form, known as symbologi
35、es, and the rules defining the translation of characters into bar and space patterns and other essential features are known as the symbology specif ication. Symbologies are of two broad categories: 0 A traditional simple format of linear symbologies, where data is encoded as a single string from lef
36、t to right. A more sophisticated format of two-dimensional symbologies where data is encoded in an arrangement of rows and columns. PDF41 7 is a two-dimensional symbology. Manufacturers of bar code equipment and users of bar code technology require publicly available standard symbology specification
37、s to which they can refer when developing equipment and application standards. It is the intent and understanding of CEN that the symbology presented in this standard is entirely in the public domain and free of all user restrictions, licences and fees. STD-BSI DD ENV 12725-ENGL 1998 W 1b24bbS ObA24
38、0Li 874 II Page 6 ENV 12925: 1997 1 Scope This European Standard specifies the requirements for the bar code symbology known as PDF41 7. It specifies PDF41 7 symbology characteristics, data character encodation, symbol formats, dimensions, tolerances, error correction rules, decoding algorithm, and
39、a number of application parameters. 2 Normative References This 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 below. For dated references, subsequent a
40、mendments to or revisions of any of these publications apply to this standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. EN 796 - Bar Coding - Symbology Identifiers EN 841 prEN 1556 - Bar Coding - Terminolo
41、gy prEN 1635 - ISO/IEC 646: 1991 - - Bar Coding - Symbology Specifications - Format Description Bar Coding - Test Specifications for Bar Code Symbols Information Processing - IS0 7-bit Coded Character Set for Information Exchange : International Reference Version NOTE: The code table is equivalent t
42、o ANSI X3.4-1986 Character Sets - Part 1: Latin Alphabet No. 1 IS0 8859-1 - Information Processing - 8-bit Single-byte Coded Graphic Extended Channel Interpretation Assignment Standard published by AIM International 3 Definitions, Mathematical Symbols and Abbreviations 3.1 Definitions For the purpos
43、es of this standard the following definitions in prEN 1556 shall apply. algorithm, application standard, ASCII, autodiscrimination, bar, bar code, bi-directional, binary, bit, codeword, column, continuous code, data character, data codeword, data compaction, data region, decode algorithm, decoder, e
44、lement, encode, error correction level, human readable character, leading zeros, linear symbology, module, modulo, multi-row symbology, n,k symbology, numeric, overhead, pad character, pad codeword, quiet zone, reference decode algorithm, row, scanner, self-checking, space, start character, stop cha
45、racter, symbol aspect ratio, symbol character, symbology, symbology identifier, symbol width, X dimension, Y dimension The following definitions also apply to this standard. 3.1.1 Basic Channel Model: A standard system for encoding and transmitting bar code data where only data message bytes are out
46、put from the decoder. A decoder, complying to this model, operates in Basic Channel Mode. 3.1.2 Cluster: One of three subsets of PDF41 7 symbol characters, all of which are mutually exclusive. The symbol characters in a given cluster conform to particular structural rules which are used in decoding
47、the symbology. 3.1.3 Error Correction Codeword: A codeword in a symbol which encodes a value derived from the error correction codeword algorithm to enable decode errors to be detected and, depending on the error correction level, to be corrected. Page 7 ENV 12925: 1997 3.1.4 Extended Channel Interp
48、retation: A procedure within some symbologies, including PDF41 7 to replace the default interpretation with another interpretation in a reliable manner. The interpretation intended prior to producing the symbol can be retrieved after decoding the scanned symbol to recreate the data message in its or
49、iginal format. 3.1.5 Extended Channel Model: A system for encoding and transmitting both data message bytes and control information about the message. A decoder, complying to this model, operates in Extended Channel Mode. The control information is communicated using Extended Channel Interpretation (ECI) escape sequences. 3.1.6 Function Codeword: A codeword in a symbology which initiates a particular operation within the symbology, for example to switch between data encoding sets, to invoke a compaction scheme,
