A bar code symbol is a parallel pattern of variable width bars and spaces; symbologies is the industry term describing the inviolable rules that specify the way that data is encoded into that pattern of bars and spaces.
The Universal Product Code (UPC) has been employed in the supermarket industry since about 1973. UPC is a coding system, as well as a symbology, that uniquely identifies both the manufacturer and its products.
There are 12 digits in the UPC Version A (UPC-A) symbology, the first six are assigned by the Uniform Code Council. They include the NSC (Number System Character) and the Manufacturer's Number.
The next five digits make up a code identifying the product, and are called the Product Code. The final digit is known as the Modulo Checksum Character or Mod Check. The value of the Mod Check is mathematically derived from a formula which used the other numbers encoded in the symbol.
When a manufacturer wants to have a UPC assigned to his products, they must first register with the Uniform Code Council. The UCC is located in Dayton, Ohio and they may be reached by phone at the following number: 937/435-3870.The UCC charges a one-time fee for registration. This fee is set upon a sliding scale based upon the financial size of your company. These folks are helpful and they will expedite processing your application for additional revenue.
The European Article Numbering system (EAN) is a superset of UPC; and while an EAN scanner will decode a UPC symbol, the UPC scanner may not necessarily decode an EAN. EAN is available in two versions, EAN-13 and EAN-8. An EAN-13 symbol contains the same number of bars as UPC-A, but additionally encodes a thirteenth digit. That digit, combined with the twelfth digit defines the two flag characters representing the country code.
All EAN symbologies start with a national identifier except those on books. In the US, if you require an ISBN Bookland EAN-13 code for a book, you must register with the ISBN Agency, represented by R.R. Bowker in New York, phone number 908/464-6800. For a fee, they will process your registration and see that you are assigned ISBN numbers. Once that is done you may contact Data Index, Inc. and we will construct a Bookland EAN-13 barcode from your ISBN numbers.
Both the ISBN number you are assigned and the Bookland EAN-13 barcode have check digits. In each case, the check digit is derived by formula from the digits of that specific number sequence, so it is likely that the check digit for the ISBN will be different from the check digit of your Bookland EAN-13 bar code.
The most widely used non-retail symbology is Code 39. This was the first alphanumeric symbology. Each Code 39 character has nine elements, four spaces and five bars. Of the nine, three elements are wide and six are narrow Code 39 symbols begin and end with and asterisk (*), the start/stop code of the symbol.
It is possible to encode a full 128 ASCII character set using Code 39. The code is self-checking and is normally not used with a check character. An optional modulo 43 check character can be used in applications that require data security. HIBCC (Health Industry Bar Code Council) has adopted the use of this check character in health care applications. If print quality is marginal, the use of Code 39' s check character is encouraged.
I 2 of 5 is a high-density, continuous numeric symbology, that is self-checking; commonly used in the distribution industry. Each I 2 of 5 character encodes two digits, one in the bars and one in the spaces. There are five bars, two which are wide and three that are narrow; and each digit has ist own unique 2 out of 5 arrangement. The complete symbol consists of a start code, the data characters and a stop code.
This code is often used with a modulo 10 check digit in the final position for improved data security. However, the check digit alone will not prevent partial scan problems. In order to minimize accidental partial scans on longer symbols, bearer bars should be used. The bearer bars must touch the top and bottom of all data bars.
Commonly used in libraries, blood banks and air parcel express applications, Codabar is a self-checking, discrete symbology with a sixteen character set: numbers 0 through 9, $, :, /, ., +, and -. There are four diffenent start/stop codes. Originally developed in 1972, traditional Codabar is most commonly used in its variant format known as Rationalized Codabar. Rationalized Codabar is totally compatible with Traditional Codabar and just as secure, but with a slightly higer density.
This a a very high density alphanumeric code; variable length, continuous code using multiple element widths. Each character has 11 modules, either black or white; three spaces and three bars. Code 128 employs three different character sets (A, B, or C) each of which contains 106 different printed characters. Three different start characters identify which character set is being used, and three shift codes permit changing character sets inside a symbol.