Code 49
The Code 49 is a 2D barcode with three error correction methods and therefore meets high security requirements over other labeling methods. Code 49 is the first multi-row code and was developed in 1987 for logistic applications in space travel by David Allais at Intermec (USA).
structure
The number of rows varies between two and four. Each row consists of a total of 70 modules, a start character (2 modules), four data words (2 × 16 modules) and a stop character (4 modules). A maximum of 49 alphanumeric characters or 81 digits can be encoded.
To ensure a high level of error security, Code 49 offers three forms of error detection
- The parity is checked for each character .
- Each line contains a check character as the last character .
- Two or three test characters are appended to the end of the code.
Code 49 has six control codes with special functions. With an extended decoder , the code can be identified by all conventional reading devices. Before decoding , the entire block of code must have been captured.
A detailed code specification is available from the Association for Automated Identification and Mobility .
literature
- BARCODAT: 2D primer . Dornstetten 2007.