Simply put, a barcode scanner replaces keystrokes from your keyboard by scanning a barcode which translates the lines on a barcode label to a product number. The POS system then looks up the product number in its database and finds the relevant description, price and other details. Barcodes greatly increase the speed and accuracy of sales processing.
There are three basic technologies adopted by scanner manufacturers; CCD, Laser and Linear Imaging.
CCD scanners
CCD (Charged Coupled Device) scanners are based on older technology. The scanners emit a fuzzy red beam which reads the barcode. CCD scanners normally need to scan at a distance of less than 10cm, with the cheaper models needing to be almost scraped over the barcode. For this reason CCD scanners are not recommended for curved surfaces such as bottles.
Laser scanners
Laser scanners emit a thin red laser beam which can accurately read barcodes from a distance of around 30-50cm. The laser beam needs to be scanned horizontally across the barcode. A further enhancement to laser technology is omni directional scanning. The scanner emits multiple beams at different angles, so that it does not matter what angle the barcode is scanned.
Linear Imaging scanners Linear Imaging is based on CCD technology. As linear imaging technology makes new advances, it is being considered comparable to a laser scanner. A laser scanner has the ability to scan 30 to 50 scans per second, while imaging scanners double those speeds at more than 100 scans per second.
CONNECTIVITY
Scanners can be connected to your computer in 3 basic ways; Keyboard wedge, USB or Serial.
Keyboard Wedge
The keyboard wedge scanner comes with a piece of "Y" shaped cable that has two PS/2 connectors - one male and the other female. The one end of the cable goes to the computer's keyboard PS/2 port, and the PS/2 keyboard plugged into the other end, so that the scanner is able to input data to the computer as though it were typed on the keyboard. Keyboard Wedge scanners are plug&play, just like the computer keyboard. Many computers now come standard with a USB keyboard. In this case you should avoid a keyboard wedge scanner. Using a USB>PS/2 adapter will not necessarily work.
USB
USB interface is probably the most common barcode scanner interface nowadays, it requires no software driver, and it is of course also plug&play. Another advantage of using the USB interface is that it is compatible with all notebook/laptop computers that have a USB port.
Serial (RS-232)
Data is sent in ASCII format at RS-232 levels (Most Common handshaking is 9600,N,8,1 for barcode scanning devices with serial interface). Serial ports on a PC are RS-232, however the user must have software drivers to input data from the port. Before purchasing a serial scanner, you should ensure your POS application software supports RS-232 communication. Testing of an RS-232 barcode scanner can be done via the default Windows Communication Tool - HyperTerminal (Hyperterm.exe). You would need to run HyperTerminal, select the COM port where your scanner is connected, and assign the suitable handshaking properties (baud rate, parity, and start/stop bit), scan few barcodes and see if the scanned data comes out correctly in the HyperTerminal screen.
The above options are given as an outline only. Scanners can normally be programmed for specific purposes, for example, adding a carriage return, keyboard wedge for use without a keyboard, or for use on a laptop etc. This is done by scanning a sequence of barcodes as specified in the manaufacturers handbook.
PRICING
Datalogic Touch65 CCD (KBW/USB/Serial) $295 (60mth warranty)
PSC QS1000 laser (KBW) $395 (24mth warranty)
PSC QS1000 laser (USB) $425 (24mth warranty)
PSC QS1000 laser (Serial) $455 (24mth warranty)
PSC QS6000 laser (KBW/USB) $455** (60mth warranty)
PSC QS6000 laser (Serial) $495** (60mth warranty)
PSC QS6500 linear imager (KBW/USB) $425** (60mth warranty)
PSC QS6500 linear imager (Serial) $495** (60mth warranty)
Symbol LS-2208 laser (KBW/USB/Serial) $395 (60mth warranty)
Symbol LS-9203 Omni-directional laser (KBW/USB/Serial) $595 (24mth warranty)
Symbol LS-9208 Omni-directional laser (KBW/USB/Serial) $745 (30mth warranty)
Gryphon M100 cordless CCD (30cm range) (KBW/USB/Serial) $1250 (30mth warranty)
** add $55 for stand