A multi-level barcode developed by Computer Identics Corp. in 1981, named for being able to symbolize 128 characters in full-ASCII.
In other barcodes, one character can express one type of data. In CODE-128, through the selective use of the start character, one character can express three types of data in any position.
- Selective Start Characters
Start Code – A = following characters are expressed using full-ASCII. Start Code – B = following characters are expressed as a 1-digit alpha-numeric or a mark. Start Code – C = following characters are expressed as a 2-digit number.
Change in Data Content By Start Character
- Code Set Character
Code – A : changes the type of following characters to full-ASCII. Code – B : changes the type of following charactesr to 1-digit alpha-numeric. Code – C : changes the type of following characters to 2-digit numbers.
- Shift Characteralters only the following single character from A –> B, B –> C, or C –> A, then back to the original type code.
- Function Charactera character for special definition; for example, by inserting FC1 after the Start-code character, it indicates that the data is coded in the UCC/EAN-128 format.
With its flexible functionality, it has been adopted as worldwide-common supplemental code for physical distribution.
Summary of Code-128 Symbol
|Length of symbol||variable|
|Checkdigit||Needed (modulus 103)|
|Character Density||about 5.83 chars/cm|