ASP Microcomputers - Relatively Simple Technology Drives Barcode Scanners

Relatively Simple Technology Drives Barcode Scanners

There is no question that barcode scanners are one of the most important innovations ever to hit the supply chain. No matter where a product is in production, in shipping, or in the sales channel, it is touched by barcode scanners. Industry has come to be so reliant on this simple technology that it is hard to imagine that we could get by without it. But what about the barcodes that the barcode scanners read? What do they mean?

The barcodes we see in the grocery store are the standard barcodes that are also referred to as UPC code. UPC stands for Universal Product Code. For something that looks so random, it is actually extremely detailed in its design. Each of the bars has a precise height and width. Many also have a series of numbers and letters below the black and white bars. The size of each bar is representative of specific information such as model number, location, and the like. Each digit on the code has a meaning. For example, the first 6 digits may represent the manufacturer and the remaining digits the item number. A person has to have the job of assigning these numbers, which means that there are a lot of UPC coordinators out there. Each manufacturer will have to have someone whose responsibility it is to assign the number and make sure there is no duplication.

In addition to the manufacturer number and item number, each barcode has what is known as a check digit. This is the very last number of the code. Each time an item is scanned, an algorithm is calculated. If the last UPC digit equals the calculated number, then the barcode scanner knows that the item has scanned correctly. It is significant to remember that some businesses create their own barcodes for specific purposes. For most of us, understanding what a UPC is will normally suffice.

Now, for the job of the actual barcode scanners. These relatively simple machines have the job of taking the number off of the package and getting it to a computer database where it can be used for things such as stock control or customer purchase.

Barcode scanners consist of three basic elements: a source of illumination, a sensor/converter, and a decoder. The source of illumination is either LED (light-emitting diode) or laser. This is the part that is run across the code in order to "read" it. Using the reflection of the light back to the sensor, the code information is converted from an analog signal to a digital signal. It is this digital signal that is decoded and sent to the computer or other device that will use the information.

Actual barcode scanners range from the simplest, a pen style single LED tool, to the sophisticated laser barcode scanners. Regardless of how sophisticated the illumination system, the process works the same. The key variation in the different lighting systems is how quickly they work and what their range is. The pen style, for example, must be run across the code in order to pick up all the information while a high end laser system can scanned from a remarkably long distance.

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