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Code 128 Barcodes
Code 128 barcodes are a high-density, variable-length barcode symbology widely used across various industries for encoding alphanumeric data. Unlike linear barcodes such as Codabar, Code 128 barcodes can encode a much larger set of characters, including all 128 ASCII characters. This versatility makes Code 128 ideal for encoding complex information such as product serial numbers, shipping labels, and inventory tracking codes. Additionally, Code 128 supports three different character sets (A, B, and C), allowing users to optimize barcode size and data density based on their specific requirements.
One of the key advantages of Code 128 barcodes is their high data density, which allows for compact representation of large amounts of information. This makes Code 128 barcodes particularly useful in applications where space on the label or product packaging is limited. Furthermore, Code 128 barcodes are highly reliable and offer built-in error detection and correction mechanisms, such as checksum digits. These features help ensure accurate scanning and decoding of the barcode, even in challenging environments. Overall, the versatility, compactness, and reliability of Code 128 barcodes have made them a popular choice for businesses seeking efficient and effective data encoding solutions.
Code 128 is a high-density 1D barcode symbology. This barcode set makes use of the entire 128 ASCII characters which include letter, number and symbols.
As with all barcodes, there are indicators to identify where the barcode starts and stops. These are marked in yellow below. Code 128 also has a check character which has been marked in green. The remainder of the barcode is the data being encoded. The text below the barcode is optional and is for human consumption in the event the barcode can't be scanned or if people also need to know what the code means.
Each character in the barcode symbol is composed of three bars and three spaces. Each bar or space must range from 1-4 units and the sum of all the width of all bars must work out to an even number. The stop marker is special because it adds an extra bar of 2 units at the very end (4 bars and 3 spaces). There are three different start markers to to identify which code set is being used. To represent all 128 characters, the code sets can be within a single barcode as needed by using control characters 98-101 (depending on the code set).
The check character is calculated by summing the value of each character and multiplying it by its position. The start character is also part of the sum but is added without weight (multiply by 1 just like the first encoded data character) then when you have the sum take the modulo 103 remainder. This gets a little more complex when mixing modes within a single barcode.