Guangzhou State Association | Honeywell barcode scanner | scanner provided by the Guangzhou State Association. We are Guangzhou City State Association Information Technology Co., Ltd. (www.gzdb899.com) located: Guangzhou specializes in: cash register, scanner, bar code machines, management software, small ticket machines, cash registers, shredders serial barcode scanning In fact, guns and keyboard barcode scanner, its advantages and disadvantages who is a: external power supply. Why use a serial barcode scanner? External power a little ugly in appearance Honeywell barcode scanner, and a power connector must Cadogan, but precisely because of this, it does not use the computer's power supply voltage is guaranteed. Some bar code scanner for voltage requirements are relatively high, keyboard port connected barcode scanner after this load, the voltage on the low down, is not working. And serial port can take a variety of host devices: PC, cash registers, terminals, barcode scanner keyboard port in the application scope is not as good as it. Let's make a comparison, in fact, should choose serial or keyboard port according to their own needs. Compare the contents of the serial keyboard port USB port power supply external, such as organic within the power supply can also be converted Symbol barcode scanner, such as PC, POS machines are also available from the PS / 2 fetch electricity (expert level in order to do so) from the keyboard, no external power supply USB port, no external RS232 standard length by 200 feet (60 meters), the actual but also longer 1.5 to 5 m USB specification 1.5 to 3 meters Applications PC, POS, industrial machines, terminals, data terminals PC , part of the POS machines, part of the terminal PC, Mac driver Scanpard, WinCom2key, com2key need to be supported by Windows, Windows built-in input speed the pace has not been tested principles and types of barcode scanner barcode scanner in conjunction with the other two are used for reading device information contained in the bar code, bar code readers structure is usually the following parts: a light source, the receiving device, photoelectric conversion parts, decoding circuitry, computer interface. Their basic working principle is: the light emitted by the light source through the optical system is irradiated to the bar code symbol above the light is reflected back through the optical system is imaged on the media converter, thus producing an electrical signal Honeywell 5145 laser barcode scanner , the signal after amplification circuit generates an analog voltage, which is proportional to the exposure to light is reflected back on the bar code symbol, and then filtered, shaping, forming a corresponding analog signal square wave signal scanner, the decoder interpreted as the computer can directly receive the digital signals. Ordinary barcode scanner usually following three techniques: light pen, CCD, laser, they have their own advantages and disadvantages, no one scanner can have an advantage in all respects.