Bar Codes

Bar code is an automatic identification technology that allows rapid data collection and does it with extreme accuracy. It provides a simple and easy method to encode information which is easily read by inexpensive electronic devices. Bar code is a defined pattern of alternating parallel bars and spaces, representing numbers and other characters that are machine readable. Predetermined width patterns are used to code data into a printable symbol. Bar codes can be thought of as a printed version of the Morse code in that the narrow bars represent dots and the wide bars represent dashes.

The bar code reader decodes a bar code by scanning a light source across the bar code and measuring the intensity of light reflected back to the device. The pattern of reflected light produces an electronic signal that exactly matches the printed bar code pattern and is easily decoded into the original data by simple electronic circuits. There are a variety of different types of bar code encoding schemes called symbologies, each developed to fulfill a specific need in a specific industry. Bar code technology is designed to function best with a red light as a scanning spot and is designed to be bidirectional to increase performance. The bidirectionality remains the same if bar codes are read from top to bottom/bottom to top, or left to right/right to left. Currently over 40 bar code symbologies have been developed with their unique scanning device.

Since bar code symbologies are like languages that encode information differently, a scanner programmed to read a particular code cannot read another. Some of the commonly encoding schemes or “symbologies” are code 39 (Normal and Full ASCII), Universal Product Code (UPC-A, UPC-E), and European Article Numbering system (EAN-8, EAN-13). The EAN symbologies adhere to the same size requirement.

In summary, the use of bar coding systems assists in the collection of data for production control, automatic sorting systems, or monitoring work-in-progress. As such, bar coding provides accurate, immediate information; thereby, it facilitates the decision making process.