ROSISTEM
Barcode Education » Code 11 (USD-8)

Code 11 (USD-8)

Code 11 (USD-8) is a high-density numeric symbology developed in 1977, primarily used for labeling telecommunications components and equipment.

Introduction

Code 11 was developed in 1977 as a high-density numeric symbology. It is also known as USD-8, and is primarily used for labeling telecommunications components and equipment.

Code 11 is a numeric symbology whose character set consists of 10 digits and the dash symbol (-): 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -.

Code 11 uses one or two weighted checksum digits. Normally, if the message is shorter than 10 characters, only one checksum digit ("C") is used. Otherwise, both "C" and "K" are used.

Code 11 is a discrete symbology. Characters are separated by an inter-character gap that typically has the same width as the narrow element.

The height of the bars must be at least 0.15 times the symbol's length, or 0.25 inches, whichever is larger.

The name derives from the way the "C" checksum digit is calculated. See the checksum section below for details.

Although Code 11 is discrete, it is not self-checking, because a single printing defect can transpose one character into another valid character.

Structure of a Code 11 barcode

A typical Code 11 bar code has the following structure:

  1. A start character
  2. The encoded message
  3. The "C" check digit
  4. If the length of the encoded message is greater than 10, a "K" check digit is also required.
  5. A stop character
Check Digit Calculation

To calculate the optional checksum digit, follow these steps:

  1. Start with the right-most digit in the message; assign it a weight starting at 1. Move from right to left, incrementing the weight by one each time. A dash has a value of 10.
  2. Multiply each character's value by its weight and sum the results.
  3. Divide the total by 11. The remainder is the "C" checksum digit.
  4. If the message is longer than 10 characters, the "K" digit must also be calculated.
  5. Start with the right-most digit in the message (which now should include the "C" digit). Repeat step 1. This time, divide the result by 9. The remainder becomes the "K" checksum digit.