Appendix C
Specifications for Code 39
Code 39 (or Code 3 of 9) is the de facto standard of
The name "Code 39" comes from both the fact that its character set originally contained 39 characters (it now has 43) and from its structure. Each character is formed of three wide and six narrow elements, made up of five bars and four spaces. Code 39's density can vary from a low
of .75 characters per inch (cpi) to a high of 9.4 cpi.
*C39* There should be a ¼" "quiet zone" (white space) to the left and right of the bar code.
Code 39 uses an asterisk (*) as a start and stop character. This character must precede and follow the data in the bar code. The RF Laser Reader gives you the option of transmitting or not transmitting these characters when the bar code is read.
Exact specifications for Code 39 and other bar code symbologies can be obtained from ANSI at the address below:
American National Standards Institute
Customer Service
11West 42nd St., 13th Floor New York, NY 10036
document ANSI/AIM BC1-1995
Code 39 has several advanced features and functions that are discussed further in this appendix.
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