User manual

A–4 CCD Operation and Bar Code Scanning

A.3 Bar Code Basics and Scanning Tips

A Closer Look At Bar Code Symbols

42000 06200

The illustration at the right shows a typical bar code

symbol. If you look at it closely, you’ll see it is

composed of a series of dark lines (bars) and white

areas (spaces) of various widths. By arranging these

bars and spaces in a certain order, it is possible to

represent, or “encode” letters, words and numbers.

You may also print the numbers represented by the bar code symbol on the label. These

human readable characters allow you to know exactly what information the scanner is

sending to the register or terminal. The human readable characters under the bar code

symbol also allow you to key in information in case the bar code symbol is not readable.

The blank area located just before and just after the bar space pattern is called the “quiet

zone.” It is placed on the symbol so the scanner knows exactly where the bar code

begins and ends. It is important to remember where the quiet zone is located so you can

scan accurately.

Bar Code Scanning

The purpose of the bar code scanner is to “read” the image formed by the bars and

spaces. A signal sends the information printed on the bar code symbol to the terminal.

Several types of scanners are in use today. The most common types include the wand

scanner, the laser scanner, and the CCD scanner. All scanners use optical systems which

are protected by “windows” at the scanning end to read the bar code symbol. On wand

scanners, the window is located in the tip. Laser and CCD scanners have a larger and

more noticeable viewing “window.” It is important to keep these optics clean, because

just like the lenses on reading glasses, if they become dirty, scratched or smudged, they

won’t work properly.

If your scanner is attached to a decoder (or it is also a decoder), the decoder may have a

beeper that will let you know when a scan has been performed properly and that the bar

code has been read accurately. After you’ve scanned a symbol, listen for a single beep,

(called a “good read” beep). This lets you know that the bar code information has been

received by the terminal. If you don’t hear the single beep or if you hear several beeps, it

means the symbol is unacceptable to the decoder, and the terminal has not received the

bar code information. If that happens, try scanning the symbol again.

Before using any scanner, make sure the symbol is of good quality and that the optic area

of your scanner is clean. Any dirt or specks in the bar code symbol or on the scanner

optics may prevent it from reading accurately. Even a symbol that is smudged during

printing, or gets wrinkled when it is applied to an object can cause a reading problem. If

you can’t get a good read beep or you begin to receive error beeps, be sure to check the

scanner optics and the symbol. The decoder may need to enable the beeper, either with a

hardware configuration or with a software command.