The BarCode Reader
What is a Bar Code?
A Bar Code is just a different way of encoding numbers and letters by using a combination of bars and spaces of varying widths. This is just another way of entering data into a {color=blue]computer. A bar code does not contain descriptive data. It is a reference number that a computer uses to look up an associated record that contains descriptive data and other important information. For example, a barcode found on a soda can does not contain the product name, type of soda, or price, instead, it contains a 12-digit product number. When this number is scanned by the cashier at the check-out, it is transmitted to the computer which finds the record associated with that item number in the data base. The matching item record contains a description of the product, vendor name, price, quantity-on-hand, etc. The computer instantly does a "price lookup" and displays the price on the cash register. It also subtracts the quantity purchased from the quantity-on-hand. This entire transaction is done instantly. In a nutshell, a bar code typically has
ID data encoded in it, and that data is used by computer to look up all specific information associated with the data. Now you may ask, but how does computer know what those bars and spaces are? Well, let s go to bar code scanning section.
What is a Bar Code reader or Bar Code scanner?
Computers can not read bar codes. For a computer to make use of the information contained in the bar code, the bar code data must be captured and decoded into a data format that the computer can process. The device that reads or captures the bar code information and sends it to the decoder is known as the bar code reader, generally called bar code scanner.
How does a bar code reader or bar code scanner work?
A typical Bar Code Reader kit consists of Scanner, Decoder, and Cable that interfaces the Decoder to the computer. The Scanner scans the Bar Code symbol and captures the bars and spaces of the bar code and sends it to the decoder. The decoder translates the bars and spaces into corresponding electrical output and transmits that data to the computer in a traditional data format. A bar code scanner can either have the Decoder built into it, or be "undecoded". Undecoded bar code scanner requires a separate box called an interface or keyboard wedge.