code 39 Introduction

Three nine bar code is code 39, which is a kind of bar code developed by an American company in 1975. It is a kind of bidirectional bar code that can encode 44 characters such as numbers, English letters and other characters. It is non-continuous, non-fixed length and has the function of self-validation.

Each bar code character of the SAN Jiu bar code is composed of five "bars" and four "blanks" in a total of nine units, of which there are three wide units, the rest are narrow units, and hence the name. Sanjiu bar code has the function of self-validation, so that Sanjiu bar code has the advantages of low error rate.

At present, Sanjiu bar code is widely used in the automobile industry, material management, economic management, medical and health, postal, storage and transportation units and other fields.

Three nine bar code symbol features:

1) Coded character sets: all alphanumeric characters except for some special symbols (note that this does not include full ASCII codes and control function selection);

2) The number of data characters: variable, up to 16 characters;

3) Symbolic validation characters: 43 modulus symbolic validation characters should be used and output;