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Codabar

Codabar (also known as Codeabar, Ames Code, NW-7, Monarch, Code 2 of 7, Rationalized Codabar, ANSI/AIM BC3-1995 and USD-4) is a relatively old (invented in 1972) linear barcode. It encodes digits, arithmetic operations (+-*/), colon (:), dollar symbol ($) and letters A to D. in some specifications, E, N, asterisk, and T are used in matching pairs to mark the beginning and end of the code. As of 2010, Codabar is still in use.

This applet converts user input into codabar. If your input cannot be represented in codabar, the applet shows red crossing lines.

Codabar can be accurately read even when printed on dot-matrix printers. While not as dense as newer barcodes, Codabar has a large installed base in libraries. It is even possible to print Codabar codes using typewriter-like impact printers, which create a large number of codes with subsequent numbers without any digital equipment. After each printed code, the printer's stamp is mechanically turned to the next number, as for example in mechanical mile counters.

Encoding

This code is essentially a kind of alphabet that directly converts symbols into barcode fragments. The table, how every symbol is converted to barcode fragment, is given below. Depending on the particular specification, Codabar can represent multiple digits. Some specifications define additional symbols but they do not cover complete alphabet. There is no standard check digit.

Each character comprises 7 binary identifiers (4 bars and 3 spaces). Each identifier or element is made up of a certain multiple of constant-width modules. Different specifications allow for different width modules, the smallest being 0.0065 inches, allowing 11 characters per inch to be encoded. Logical 0s and 1s are represented by narrow and wide elements respectively[1].


Char. Pattern Bars Spaces
0 lll l 0001 001
1 lll l 0010 001
2 ll ll 0001 010
3 l lll 1000 100
4 lll l 0100 001
5 lll l 1000 001
6 l lll 0001 100
7 l lll 0010 100
8 l lll 0100 100
9 ll ll 1000 010
- ll ll 0010 010
$ ll ll 0100 010
: llll 1011 000
/ llll 1101 000
. llll 1110 000
+ llll 0111 000
A or T ll l l 0100 011
B or N l l ll 0001 110
C or * ll l l 0001 011
D or E ll l l 0010 011

Acknowledgements

This web page reuses material from Wikipedia page http://en.wikipedia.org/wiki/Codabar under the rights of CC-BY-SA license. As a result, the content of this page is and will stay available under the rights of this license regardless of restrictions that apply to other pages of this website.


References

  1. 1 http://www.barcodeman.com/info/codabar.php

See also