Worth Data 5000 TriCoder s Dokumentacja Pobierz pdf (Strona 20)

to the scanner. Unless the bar code is on the surface of the item pointing straight

up, the bar code reader has a good chance of reading it. These devices are

required to be integrated into the sales counter. They typically directly interface

with a retail POS terminal.

On Counter Scanners

These devices are the smaller cousins of the Supermarket Slot Scanner. They

were developed for the convenience stores that wanted automation but didn't

have the counter space required for a slot scanner installation. They also have

an omni-directional light source to free the user to present the bar code in any

orientation. They sit on a counter, or they sit on a stand that sits on the counter.

Items are passed a few inches in front of the scanner to get a successful read.

Industrial Scanners

There are also a whole line of scanners made just for industrial applications

including small under $1000 scanners that read a few inches distance and large

$20,000 long range scanners that read twenty feet away. These are typically

mounted adjacent to conveyor lines to read bar codes on passing items; the host

computer then directs the items to the appropriate branching line. A classic

example of such scanners use is airport baggage sortation (those bar codes that

are placed on your luggage are actually used in the large airports to get your

luggage to the right place.) This type of equipment is almost always sold with

turnkey hardware (including conveyors) and software by specialty integrators. A

source for industrial laser scanners is:

• Microscan

800-251-7711, or in WA 425-226-5700

www.microscan.com

CCD Scanners

CCD scanners are a “can’t miss” scanner too. Most have to be placed on the code

for reading but some offer “laser-like” distance reading. Some are trigger-less and

some require the trigger or button to be pushed to initiate reading. CCD scanners

scan around 50 times per second; so unsuccessful read attempts go unnoticed.

Traditional CCD scanners have a “depth of field”, (how far you can be away

from the bar code and still get a read), of only ½”. They have to be placed on the

code to get a read. Just recently, CCD scanners have been developed with a

depth of field previously only achieved by laser scanners. These CCD scanners

are so unique that they have been termed “Linear Imager” scanners.

With Laser scanners and CCD scanners now sharing the same range, it is

important to know the difference between them. Laser scanners use a single spot

of light that sweeps across the bar code in a linear fashion. In a sense, lasers act

like a wand, transmitting the signal for each bar and space as it “scans” across.

This “scanned” pattern is then decoded. A CCD scanner on the other hand, uses

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