Code 11 (also called USD-8) is a numeric-only barcode developed by Intermec in 1977. The symbology can encode the digits 0 through 9, a dash, and includes both a stop and start character. Code 11 is variable length with the only limit on length being the width available for print. Code 11 is a linear, one-dimensional (1D) barcode. This means the barcode is composed of a single set of varying width vertical lines and spaces. The data in the barcode is represented linearly by these black/white (bar/space) patterns. Below is a simple example.
Each character in a Code 11 barcode consists of 3 bars (black) and 2 spaces (white)—every character starts and ends with a bar. Of these five elements, two are always “wide” (twice the width of a “narrow” element), and three are always narrow. The symbology also includes distinct start and stop characters.
The symbology is further characterized as a discrete barcode, meaning that each character is separated with an inter-character gap element (typically a single white element, though larger gaps are permitted). Here is our example again, diagramed for clarity:
Code 11 is considered a weak or insecure symbology, as a single print or read error can result in a misinterpreted character. To combat this, a single character check digit is often used with messages of fewer than 10 digits, and a two-character check digit is used for longer messages. In the preceding examples, the last digit (8) is actually the computed check digit for the data message (4321).
While developed as a high-density, numeric barcode, because of its poor reliability, Code 11 is not widely used. Code 11 is primarily used in the labeling of telecommunications equipment.
The Cognex Mobile Barcode Scanner SDK supports Code 11 detection, enabling developers to gather relevant workflow and application data into their own apps. You can download the SDK for free by registering on the Cognex Mobile Barcode Developer Network. In addition, the Barcode Scanner SDK supports a broad range of symbologies to meet your growing development needs.