Below is an example of one of the most common 2-D matrix code types, the Data Matrix code. They are among the most frequently used 2-D codes in the Factory Automation industry.
2-D Matrix Code Size
Each 2-D matrix code is made up of a specific number of modules. Modules within a code are all the same size and do not change. However, the total number of modules can vary depending on number of rows and number of columns. For example, the overall size of a 10x10 matrix code can be the same overall size as a 20x20 matrix code except the 20x20 has half of the module size.
In order to properly decode a matrix code, the size of one module and the total number of modules within the code must be identified and understood. Below is a diagram of a 16x16 Data Matrix code.
Similar to 1-D barcode Quiet Zones, 2-D matrix Quiet Zones are the margin of white space around the entire code. 2-D matrix codes must have a Quiet Zone in order to be decoded correctly.
The Finder or “L” Pattern is how the code is located.
The Clocking Pattern is opposite the finder pattern and alternates black and white boxes or modules. It is the Clocking Pattern that is used to establish the module size of the code.
Note: 2-D codes can only be read using an image based ID reader.
The diagram below outlines the different features and symbol terminology for a 2-D Data Matrix code. The diagram key is below.