Bar Codes Fundamentals
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USS-TSS Unattended Scanning Systems Technical Support & Services Barcodes and 2D codes Place - DD/MM/YYYY - Session XX Bar Codes Fundamentals Datalogic Automation Agenda Datalogic Automation When: Day DD/MM/YYYY Where: Place Who: Speaker / Professional qualification What: Bar Codes Fundamental Duration: HH:MM hours Level: Basic Bar Codes Fundamentals Confidential Documentation Datalogic Automation Module’s Contents Main Bar Code Characteristics Code 2 of 5 Interleaved Code 39 Code 128 Code EAN128 and Application Identifiers (AI) A Comparison Between Codes 2/5, 39, 128 EAN/UPC/JAN Family Other codes Summary Bar Codes Fundamentals Confidential Documentation Bar Code Principles (1/2) Datalogic Automation Element or Module Bar or Space Bar Count number of Bars and Spaces Start/Stop fixed patterns used to detect bar code Resolution X module size width of the narrowest element in mm (mils in USA) Aspect Ratio Bar’s height to symbol’s length Quiet Zone White margins Overflow Quiet Zone time duration) Usually the Quiet Zone width must be 10 times X Bar Codes Fundamentals Confidential Documentation Datalogic Automation Bar Code Principles (2/2) Start pattern Stop pattern Quiet Zone Quiet Zone 123456 Scan Line Bar Codes Fundamentals Confidential Documentation Datalogic Automation Bar Code Types: Levels 2 Levels Bar Codes (Interleaved 2 of 5, Code 39, Codabar …): Elements can assume only two different widths: 1X (Narrow), 2X (Wide) N = Printing Ratio = ratio between the wide and the narrow element The range of N is from 2 : 1 to 3 : 1 4 Levels Bar Codes (Code 128, EAN 128, EAN-8, EAN-13, UPC-A, UPC-E, JAN …): Elements can assume only four different widths: 1X, 2X, 3X, 4X Printing Ratio N does not apply Bar Codes Fundamentals Confidential Documentation Datalogic Automation Bar Code Types: Continuous/Discrete Continuous: all spaces within the symbol are parts of characters. Examples: IL2/5, 128, EAN128, EAN-8, EAN-13, UPC-A, UPC-E … Edge of next character Character Character 1 2 Character 3 Discrete: the spaces between the characters (Inter Characters Gap) are not part of the characters. Examples: code 39, Codabar … Inter Character gaps Character Character Character 1 2 3 Bar Codes Fundamentals Confidential Documentation Datalogic Automation Bar Code Types: Self-check Self-Checking: a single printing defect will not cause a character to be transposed into another valid character in the same symbology Non Self-Checking: without self checking feature Bar Codes Fundamentals Confidential Documentation Datalogic Automation Bar Code Families Most used in Transportation & Logistics Code Interleaved 2 of 5 Code 39 Code 128 and EAN-128 Codabar (NW-7 in Japan) Other common Bar Code families (Retail) EAN/UPC family (EAN-8, EAN-13, UPC-A, UPC-E with or without ADD-ON 2 and ADD-ON 5) Other older or uncommon Bar Code families: Code 93 2 of 5 Compressed, Industrial, 5 Bars, 3 Bars Matrix, BCD Matrix, 11 Matrix, 3 bars Datalogic Plessey MSI Bar Codes Fundamentals Confidential Documentation Datalogic Automation Code 2 of 5 Interleaved (1/5) 2 levels bar code Numeric only Continuous Self-checking Optional check digit (modulo 10) Variable length, but always with an even number of digits Use of the check digit with an even number of digits is possible by adding a leading “0” Each digit is represented by 5 elements (all bars OR all spaces), 2 of which are wide (2 of 5) Odd digits are coded by bars while even digits are coded by spaces Bars of the odd digits are interlaced (Interleaved) with the spaces of the even digits Bar Codes Fundamentals Confidential Documentation Code 2 of 5 Interleaved (2/5) Datalogic Automation 9 1 8 9 Bar Codes Fundamentals 7 0 6 2 Confidential Documentation Datalogic Automation Code 2 of 5 Interleaved (3/5) START pattern is made up of 2 narrow bars and 2 narrow spaces STOP pattern is made up of one wide bar, one narrow space and one narrow bar Left and Right Quiet Zones width must be at least 10 times the module size X The wide elements are N times the narrow ones N is the Printing Ratio and can range: from 2 : 1 to 3 : 1 for X >= 0.508 mm (20 mils) from 2.2 : 1 to 3 : 1 for X < 0.508 mm (20 mils) Bar Codes Fundamentals Confidential Documentation Datalogic Automation Code 2 of 5 Interleaved (4/5) quite compact, but … ... not extremely safe Start and Stop pattern can easily be found inside a code Variable length should be avoided (possible truncations using code reconstruction) Use of check digit only reduces but does not eliminate the risk of misreading AIM IL 2/5 Uniform Symbology Specification says: “… There is no guarantee that a partial scan of the symbol will not produce a valid read for an embedded symbol having fewer characters. It is strongly recommended that USS I 2/5 should not be used in an application where the number of characters can vary …” Bar Codes Fundamentals Confidential Documentation Datalogic Automation Code 2 of 5 Interleaved (5/5) Length of the Start: 4X Length of a Character: 3X + 2NX Length of the Stop: 2X + NX Total Code Length : 4X + D(3 X+2NX) + 2X + NX = X (6 + N) + DX(3 + 2N) = X [6 + N + D(3 + 2N)] The number of Digits can be easily calculated as follows: D = (Bar Count - 7) / 5 or D = (Number of Wide Bars – 1) (where 7 are the elements of the Start and the Stop patterns and 5 are the elements which represent each single digit) Bar Codes Fundamentals Confidential Documentation Datalogic Automation Code 2 of 5 IL: ITF Codes (1/3) A particular code Interleaved 2 of 5 is referred to as ITF-14 (EAN specifications) It is very common on carton boxes for large distribution The same code can assume other names: DUN-14 (Delivered Unit Number) TUN-14 (Traded Unit Number) ITF-6 is similar but with 6 digits instead of 14 Bar Codes Fundamentals Confidential Documentation Datalogic Automation Code 2 of 5 IL: ITF Codes (2/3) As per EAN specifications, the dimensions in the picture are related to Magnification Factor 1, where X = 1.016 mm (40 mils) and H = 31.8 mm Bar Codes Fundamentals Confidential Documentation Datalogic Automation Code 2 of 5 IL: ITF Codes (3/3) ITF Magnification Factors and dimensions table (EAN specifications) Bar Codes Fundamentals Confidential Documentation Datalogic Automation Code 2 of 5 IL: IATA Codes (1/3) A particular code Interleaved 2 of 5 is referred to as IATA Code and it is used in airport applications(IATA Resolution 740) It is a 10 digits 2 of 5 IL code with the following characteristics X = 0.5 mm N=2:1 H min = 48 mm 2 possible layouts: “T” type label “Linear” or “Single” type label Bar Codes Fundamentals Confidential Documentation ORLANDO/FLA MCO CMH 0000 XB 123456 XB AIRLINES SAMPLE/JOHN XY 163 P PIT-ATO/C922 APR 93 ORLANDO/FLA MCO XC 2418 CMH XB 1018 XB 1018 VIA XC 2418 TO MCO XC 2418 VIA CMH ORLANDO/FLA MCO ORLANDO/FLA CMH 0000 XB 123456 XB AIRLINES SAMPLE/JOHN XY 163 P PIT-ATO/C922 APR 93 ORLANDO/FLA MCO XC 2418 CMH XB 1018 XB 1018 VIA XC 2418 TO XB AIRLINES SAMPLE/JOHN PRNTR-999999 XY 163 P PIT-ATO/C922 APR 93 0000 XB 123456 ORLANDO/FLA MCO TO CMH XB 1018 0000 XB 123456 XC 2418 VIA TO 0000 XB 123456 0000 XB 123456 XB 1018 0000 XB 123456 Bar Codes Fundamentals XB AIRLINES SAMPLE/JOHN PRNTR-999999 XY 163 P PIT-ATO/C922 APR 93 0000 XB 123456 Datalogic Automation Code 2 of 5 IL: IATA Codes (2/3) Code 2 of 5 IL IATA “T” Type: the same code is repeated in orthogonal positions Confidential Documentation ORLANDO/FLA CMH 0000 XB 123456 XB AIRLINES SAMPLE/JOHN XY 163 P PIT-ATO/C922 APR 93 ORLANDO/FLA MCO XC 2418 CMH XB 1018 XB 1018 VIA XC 2418 MCO ORLANDO/FLA TO MCO XC 2418 VIA CMH XB 1018 0000 XB 123456 0000 XB 123456 TO ORLANDO/FLA MCO ORLANDO/FLA CMH 0000 XB 123456 XB AIRLINES SAMPLE/JOHN XY 163 P PIT-ATO/C922 APR 93 ORLANDO/FLA MCO XC 2418 CMH XB 1018 XB 1018 VIA XC 2418 TO XB AIRLINES SAMPLE/JOHN PRNTR-999999 XY 163 P PIT-ATO/C922 APR 93 0000 XB 123456 XB AIRLINES SAMPLE/JOHN PRNTR-999999 XY 163 P PIT-ATO/C922 APR 93 0000 XB 123456 TO MCO XC 2418 VIA CMH XB 1018 0000 XB 123456 0000 XB 123456 Bar Codes Fundamentals XB AIRLINES SAMPLE/JOHN PRNTR-999999 XY 163 P PIT-ATO/C922 APR 93 0000 XB 123456 Datalogic Automation Code 2 of 5 IL: IATA Codes (3/3) Code 2 of 5 IL IATA “Linear” Type: the code is printed only in one direction Confidential Documentation Datalogic Automation Code 39 (1/4) 2 levels bar code Self-checking Full Alphanumeric (numbers and upper case letters) and 7 special characters (- . Space $ / + %) Discrete (Intercharacter Gap) Optional Check Digit (Modulo 43) Variable length Each digit is represented by 9 elements (5 bars and 4 intervening spaces), 3 of which are wide (3 of 9) Each digit is separated from the following by a space called Intercharacter Gap (ICG) Bar Codes Fundamentals Confidential Documentation Code 39 (2/4) Datalogic Automation * Bar Codes Fundamentals B A R * Confidential Documentation Datalogic Automation Code 39 (3/4) START and STOP patterns are both made up of 9 elements and represent the asterisk character (often included in the human readable part) Left and Right Quiet Zones width must be at least 10 times the module size X The wide elements are N times the narrow ones N is the Printing Ratio and can range: from 2:1 to 3:1 for X >= 0.508 mm (20 mils) from 2.2:1 to 3:1 for X < 0.508 mm (20 mils) The nominal width of the Intercharacter Gap should be: minimum: X maximum: 5.3X for X < 0.25 mm or 3X or 1.35mm whichever is greater for X >= 0.25mm Bar Codes Fundamentals Confidential Documentation Datalogic Automation Code 39 (4/4) Length of the Start: 6 X + 3 N X + ICG Length of a Character: 6 X + 3 N X + ICG Length of the stop: 6 X + 3 N X Total Code Length: 6X+3NX + D(6X+3NX) + 6X + 3NX + (D+1) ICG = X[12+6N+D(6+3N)] + (D+1) ICG if ICG = X X[13+6N+7D+3DN] the number of characters can be easily calculated as follows: D = (Bar Count - 19) / 10 (where 19 are the elements of the Start and the Stop patterns plus one Intercharacter Gap and 10 are the elements which represent each single digit plus the Intercharacter Gap) Bar Codes Fundamentals Confidential Documentation Datalogic Automation Code 39: Full ASCII Code 39 “FULL ASCII” feature: it is possible to encode the entire ASCII 128 character set by using two-characters sequences made up of one of the standard code 39 symbols ($ + % /) followed by one of the 26 letters Bar Codes Fundamentals Confidential Documentation Datalogic Automation Code 128 (1/6) 4 levels bar code Self-checking Continuous Variable length Alphanumeric (128 ASCII characters) Check Digit is always included (Modulo 103) 3 alternate character sets A, B and C are available Each characters set has its own start pattern It is possible to switch from one set to another inside a code by the use of the shift character The stop pattern is always the same Bar Codes Fundamentals Confidential Documentation Datalogic Automation Code 128 (2/6) START Set A STOP START Set B STOP START Set C STOP Bar Codes Fundamentals Confidential Documentation Datalogic Automation Code 128 (3/6) The Start pattern, each Character and the Check Digit are represented by 6 elements with a width of 11 modules The Stop pattern is represented by 7 elements with a width of 13 modules A very important parameter is the Bar Count (BC). From the value of the Bar Count it is possible to calculate the real number of characters inside the code as follows: D = (BC - 19) / 6 Bar Codes Fundamentals Confidential Documentation Code 128 (4/6) Datalogic Automation 1 2 3 4 5 6 7 8 9 10 11 12 13 START CHAR CHECK STOP Bar Codes Fundamentals Confidential Documentation Datalogic Automation Bar Codes Fundamentals Code 128 (5/6) Confidential Documentation Datalogic Automation Code 128 (6/6) Length of the Start (A,B,C): 11 X Length of a Character: 11 X Length of the Check Digit: 11 X Length of the Stop: 13 X Total Code Length: L = X (35 + 11 D) From the total bar code length L (quite zones not included) the Module Size (X) can be easily calculated as follows: X = L / (35 + 11 D) Bar Codes Fundamentals Confidential Documentation Datalogic Automation EAN 128 Same as Code 128, but with FNC1 as first character Can use AI (Application Identifiers) Bar Codes Fundamentals Confidential Documentation Datalogic Automation EAN 128: Application Identifiers (1/5) Application Identifier (AI) specifies particular meanings to be assigned to the code content AI are coded as the 2-4 first digits into the code and there is no separators between the AI and the field content Legenda N Numeric only AN Alphanumeric F Fixed Length V Variable Length Bar Codes Fundamentals Confidential Documentation Datalogic Automation EAN 128: Application Identifiers (2/5) Some of the most used Application Identifiers (AI) are: SSCC-18 SSCC-14 Codes EAN128 with Application Identifier 00 (SSCC) are also known as 128 Case Codes Bar Codes Fundamentals Confidential Documentation Datalogic Automation EAN 128: Application Identifiers (3/5) It is possible to concatenate two or more AI fields in the same bar code: Some rules for concatenation: Each field must be separated from the previous by a FNC1 character In the output message the FNC1 character will be converted to a GS (Group Separator) ASCII character (29 decimal) It is possible to avoid the FNC1 character separator if the previous field is a fixed length one or, if variable, the maximum number of characters were used Bar Codes Fundamentals Confidential Documentation Datalogic Automation EAN 128: Application Identifiers (4/5) + + Bar Codes Fundamentals = Confidential Documentation Datalogic Automation EAN 128: Application Identifiers (5/5) EAN 128 Application Identifiers warnings: Please remember that the scanners make no check about the correct use of Application Identifiers or their concatenation An evaluation of the quality of the code made only by naked eyes can reserve a lot of (bad) surprises! A parcel sent to the “No Read” exit not necessarily means that the code was not read by the scanners Bar Codes Fundamentals Confidential Documentation Datalogic Automation Bar Codes Fundamentals IL 2 of 5/Code 39/Code 128 (1/2) Confidential Documentation Datalogic Automation IL 2 of 5/Code 39/Code 128 (2/2) Some considerations: With the same number of digits and the same module size, Code 128 Set C is more compact than Interleaved 2 of 5 Code 39 is the widest Code 128 already includes a check digit Code 128 is a 4 level bar code, thus requires more printing accuracy with respect to I 2/5 and 39 With variable length, Code 128 is more error proof than Interleaved 2 of 5 (truncations) Bar Codes Fundamentals Confidential Documentation Datalogic Automation EAN/UPC Family UPC (Universal Product Code): UPC is a fixed length numeric symbology normally used in retail applications to identify type of product, manufacturers code and the and specific product UPC numbers are assigned to specific products and manufacturers by the Uniform Code Council (UCC) EAN (European Article Number) EAN is a European version of UPC family. It uses the same size requirements and a similar encoding scheme as for UPC codes EAN bar code numbers are assigned to specific products and manufacturers by an organization called ICOF in Belgium JAN (Japanese Article Number) JAN is a Japanese version of EAN family Bar Codes Fundamentals Confidential Documentation Datalogic Automation EAN-13 (1/8) 4 levels bar code Numeric only Continuous Self-checking Check Digit is always included Fixed length : 13 (12+1) digits Each of the 12 digits is represented by 4 elements for a total length of 7 modules An EAN-13 code can be printed with different Magnification Factors (MF) JAN (Japan Article Number) codes are similar to the EAN-13 codes, but starting with 45 or 49 Bar Codes Fundamentals Confidential Documentation Datalogic Automation Bar Codes Fundamentals EAN-13 (2/8) Confidential Documentation Datalogic Automation EAN-13 (3/8) There are 2 Guard patterns on the left and on the right of 3 elements (3 modules Bar-Space-Bar) There is a Center pattern of 5 elements (5 modules Space-Bar-Space-BarSpace) Left Quiet Zone is 11 modules wide Right Quiet Zone is 7 modules wide Bar Count is fixed to 59 (BC = 3+5+3+4*12=59) The length of the code is: L = X*95 (without Quiet Zones) Bar Codes Fundamentals Confidential Documentation Datalogic Automation EAN-13 (4/8) An EAN-13 code can be printed with different Magnification Factor (MF) All Dimensions are defined by EAN for the MF = 1 Module size for MF = 1 is X = 0.33 mm When printing the code with MF different from 1, ALL the dimensions must be proportional to the MF used. Examples: if MF = 1 module size X = 0.33 mm, bars height = 22.85 mm if MF = 0.8 module size X = 0.26 mm, bars height = 18.28 mm if MF = 1.5 module size X = 0.50 mm, bars height = 34.28 mm Bar Codes Fundamentals Confidential Documentation Datalogic Automation EAN-13 (5/8) Dimensions (mm) are referred to Magnification Factor 1 (X = 0.33 mm) Bar Codes Fundamentals Confidential Documentation EAN-13 (6/8) Datalogic Automation MF can only range between 0.8 and 2 An alternative way to define the code dimensions is by the SC factor, as per the following cross reference table SC Factor 0 1 2 3 4 5 6 7 8 9 Bar Codes Fundamentals Magnification Factor 0.8 0.9 1.0 1.1 1.2 1.4 1.5 1.7 1.85 2.0 Confidential Documentation Datalogic Automation EAN-13 (7/8) EAN-13 code structure: The first 6 digits on the left are coded with a variable sequence of Set A (Odd parity) or Set B (Even parity) depending on the 13th digit of data The second 6 digits on the right are all coded with Set C (even parity). Odd or Even parity of a set is given by the number of 1s in each digit The 13th digit defines the sequence of set A or set B used to code the 6 digits on the left The first 2 or 3 digits represent the code country in which the EAN13 code was requested or other particular use of the code (like ISSN or ISBN) Bar Codes Fundamentals Confidential Documentation Datalogic Automation Bar Codes Fundamentals EAN-13 (8/8) Confidential Documentation Datalogic Automation EAN-13 Supplemental EAN-13 has been adopted as the standard in the publishing industry for encoding ISBN numbers on books and ISSN numbers on periodicals ISSN (International Standard Serial Number) Serial Publication and Periodicals Starts with 977 ISBN (International Standard Book Number) Books (Bookland) Starts with 978 or 979 Bar Codes Fundamentals Confidential Documentation Datalogic Automation EAN-8 (1/4) 4 levels bar code Numeric only Continuous Self-checking Fixed length : 8 digits Check Digit is always included Each of the 8 digits is represented by 4 elements for a total length of 7 modules The left hand 4 digits are coded in set A (odd parity), while the right hand 4 digits are coded in set C (even parity) Dimensioning considerations are the same of EAN-13 code Bar Codes Fundamentals Confidential Documentation Datalogic Automation Bar Codes Fundamentals EAN-8 (2/4) Confidential Documentation Datalogic Automation EAN-8 (3/4) There are 2 Guard patterns on the left and on the right of 3 elements (3 modules Bar-Space-Bar) There is Center pattern of 5 elements (5 modules Space-Bar-Space-BarSpace) Left Quiet Zone is 7 modules wide Right Quiet Zone is 7 modules wide Bar Count is fixed to 43 (BC=3+5+3+4*8=43) The length of the code is L=X*67 (without Quiet Zones) Bar Codes Fundamentals Confidential Documentation Datalogic Automation EAN-8 (4/4) Dimensions (mm) are referred to Magnification Factor 1 (X = 0.33 mm) Bar Codes Fundamentals Confidential Documentation Datalogic Automation UPC-A (1/4) 4 levels bar code Numeric only Continuous Self-checking Check Digit is always included Fixed length: 12 digits Each of the 12 digits is represented by 4 elements for a total length of 7 modules The left hand 6 digits are coded in Set A (Odd parity), while the right hand 6 digits are coded in Set C (Even parity) Compatibility between EAN-13 and UPC-A is achieved because the EAN table for the left hand variable parity pattern is all A for the 13th digit equal to 0 (the implicit leading 0 of UPC-A) Bar Codes Fundamentals Confidential Documentation Datalogic Automation Bar Codes Fundamentals UPC-A (2/4) Confidential Documentation Datalogic Automation UPC-A (3/4) There are 2 Guard patterns on the left and on the right of 3 elements (3 modules Bar-Space-Bar) There is a Center pattern of 5 elements (5 modules Space-Bar-Space-BarSpace) Left Quiet Zone is 9 modules wide Right Quiet Zone is 9 modules wide Bar Count is fixed to 59 (BC = 3+5+3+4*12=59) The length of the code is L = X*95 (without Quiet Zones) Bar Codes Fundamentals Confidential Documentation Datalogic Automation UPC-A (4/4) Dimensions (mm) are referred to Magnification Factor 1 (X = 0.33 mm) Bar Codes Fundamentals Confidential Documentation Datalogic Automation UPC-E (1/4) 4 levels bar code Numeric only Continuous Self-checking Check Digit is always included Fixed length: 6 + 2 digits Each of the 6 digits is represented by 4 elements for a total length of 7 modules The 6 digits are coded with a variable sequence of Set A (Odd parity) or Set B (even parity) that depends on the 8th digit The permutation table of set A and set B encoding is different from the one of EAN-13 The first digit on the left is always 0 Bar Codes Fundamentals Confidential Documentation Datalogic Automation Bar Codes Fundamentals UPC-E (2/4) Confidential Documentation Datalogic Automation UPC-E (3/4) There is a Guard pattern on the left of 3 elements (3 modules Bar-SpaceBar) There is a right Stop pattern of 6 elements (6 modules Space-Bar-SpaceBar-Space-Bar) Left Quiet Zone is 9 modules wide Right Quiet Zone is 7 modules wide Bar Count is fixed to 33 (BC = 3+6+4*6=33) The length of the code is L = X*51 (without Quiet Zones) Bar Codes Fundamentals Confidential Documentation Datalogic Automation UPC-E (4/4) Dimensions (mm) are referred to Magnification Factor 1 (X = 0.33 mm) Bar Codes Fundamentals Confidential Documentation Datalogic Automation ADD-ON 2 And ADD-ON 5 ADD-ON 2 and ADD-ON 5 are additional codes placed on the right of EAN13 or UPC-A to add user’s information. Typically, they are used in magazines or periodicals to code the number of the item (day, week or month) Each of the 2 or 5 digits is represented by 4 elements with a length of 7 modules Use of Set A or Set B encoding (variable parity) follows a complex rule (algorithm to calculate a number + use of a table of the possible combinations). This is an implicit way to implement a check digit. Bar Codes Fundamentals Confidential Documentation Datalogic Automation ADD-ON 2 (1/2) There is a start pattern (3 elements Bar-Space-Bar of 1-1-2 modules) There is a delineator (2 elements space-bar of 1-1 modules) between the digits There is no stop guard pattern Left Quiet Zone is 7 modules wide Right Quiet Zone is 5 modules wide Bar Count is fixed to 13 (BC = 2+3+4*2=13) The length of the code is L = X*20 (without Quiet Zones) Bar Codes Fundamentals Confidential Documentation Datalogic Automation ADD-ON 2 (2/2) Dimensions (mm) are referred to Magnification Factor 1 (X = 0.33 mm) Bar Codes Fundamentals Confidential Documentation Datalogic Automation ADD-ON 5 (1/2) There is a Start pattern (3 elements bar-space-bar of 1-1-2 modules) There is a delineator (2 elements space-bar of the digits 1-1 modules) between There is no stop guard pattern Left Quiet Zone is 9 modules wide Right Quiet Zone is 7 modules wide Bar Count is fixed to 31 (BC = 3+2*4+4*5=31) The length of the code is L = X*47 (without Quiet Zones) Bar Codes Fundamentals Confidential Documentation Datalogic Automation ADD-ON 5 (2/2) Dimensions (mm) are referred to Magnification Factor 1 (X = 0.33 mm) Bar Codes Fundamentals Confidential Documentation Datalogic Automation Other Codes: Codabar 2 levels bar code Self-checking bar code Discrete (Inter Character Gap) Numeric (0-9) 6 special characters: - $ : / . + 4 letters: A, B, C, D as Start or Stop pattern Optional Check Digit Variable length Each character is encoded as 7 elements, 2 or 3 of which are wide For this reason this code is also known, mainly in Japan, as NW-7 (i.e. Narrow Wide 7 elements) Bar Codes Fundamentals Confidential Documentation Datalogic Automation Other Codes: Code 93 4 levels bar code Self-checking Continuous Variable length Alphanumeric (128 ASCII characters) 2 check digits (C and K) are always included (modulo 47) Each character is coded as 6 elements (3 bars and 3 spaces) for a total width of 9 modules (10 only for the stop pattern) Data character bars can be 1, 2 or 3 times the module size 4 modules wide bars can only be found in the start and stop pattern Like Code 39 Full ASCII, extended ASCII characters can be coded as pairs with special characters Bar Codes Fundamentals Confidential Documentation Datalogic Automation Summary Before thinking there is something wrong in the scanner because a lot of parcels are sent to the No Read exit: Know very well the codes you have to read Check carefully their printing quality with a code verifier (NEVER judge the quality by eyes!) Check the position of the code on the parcel Check the scanner’s configuration Check the PackTrack calibration Check the ACR or the ACB configuration Check if the communication with the host is correct Only after this you can start to be worried !!! …… (but usually you find the problem and its solution before!) Bar Codes Fundamentals Confidential Documentation
