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The Code 39 Regular symbology was developed to meet the need for a
fully alphanumeric bar code for use with data-entry systems.
(An alphanumeric symbology can represent both letters and numbers
in its bar codes.) It is currently the most widely used alphanumeric
bar code and has been accepted as a standard code by many organizations
and given different names, including the following.
AIAG - Automotive Industry Action Group. LOGMARS - The Logistics Applications of Automated Marking & Reading Symbols (Department of Defense), recommends the use of Code 39 — Regular as the standard DOD bar code symbology. MIL-STD-1189 defines Code 39 — Regular as the standard symbology for marking unit packs, outer containers, and selected documents. HIBC - Health Industry Bar Code Council. In addition, the following organizations also use Code 39 - Regular: ANSI - American National Standards Institute. Code 39 - Regular is the only alphanumeric bar code described in their 1981 specifications draft titled Specifications for Bar Code Symbols on Transport Packages & Unit Loads. DSSG - Distribution Symbol Study Group. The Character Set Code 39 - Regular contains the following 43 usable characters: Symbology Structure Each Code 39 - Regular character is represented by nine elements: five bars and four spaces. The name "Code 39 - Regular" comes from the fact that, of the nine elements in each Code 39 - Regular character, three of the elements are always wide and six are narrow. A fifth space, an "intercharacter space", separates each bar code character from the next, but is not actually itself a part of a bar code character. The width of this space is not critical and is set to be identical to the width of a narrow space. Start and Stop Characters Code 39 - Regular also has a "start/stop" character. This character is used at both the beginning and the end of the bar code message to signal a bar code reader that a Code 39 - Regular bar code has been scanned. This character is commonly designated as an asterisk (*), but you may choose to have no start/stop characters at all or choose to let the data source specify the start or the stop character, or both. The start and stop characters are not transmitted as part of the bar code, and is not included in any check digit calculations. |
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