The last digit of the symbol is assumed to be the check digit, and it is compared to a calculated check digit to verify the symbol.
In Code 39 Full ASCII, however, 'a' is represented as '+A'.Ī modulo 43 check character can be used to enhance data security for Code 39 symbols. For example, in standard Code 39 a lowercase 'a' cannot be represented. Code 39 can be extended to an 128 character symbology (full ASCII) by combining one of the special characters ($, /, %, +) with a letter (A-Z) to form the characters that are not present in the standard Code 39 symbology. Standard Code 39 contains only 43 characters (0-9, A-Z, $, /, %, +). Listed below are the options for the Code 39 symbology. '%' which can be paired with alphanumeric characters to extend to the full ASCII character set. The Code 39 bar code uses four special characters '$', '/', '+'. Three of the nine elements (bars) are wide and six elements are narrow. The principal feature is to encode messages using the full alphanumeric character set. Code 39 is variable length and is the most frequently used symbology in industrial bar code systems today.
