One of the reasons that the use of bar codes has increased so rapidly has been the development of Keyboard Wedge reading. This enables a bar code scanner to be connected between the keyboard of a PC, or terminal, and the keyboard port. The keyboard retains all functionality and bar codes can be read directly into any application software that is being used.
Wedges are available for PCs and most mainframe terminals (IBM, Wyse, DEC, +120 more). For non-wedge applications we stock all types of reader with either undecoded or RS232 interface output. RS232 terminals can be interfaced by placing the decoder on the cable that goes from the terminal to the CPU. The same equipment can be configured to provide RS485 networks which allow the collection of data when and where required.
Contact scanning where the wand actually has to touch the bar code. Used for most applications for ease of use and low cost. For library circulation, scans up to 3,500 per day are common for wands.
Non-contact scanning where the scan head never touches the bar code. The scanning distance is dependent on two factors: the X dimension of the bar codes and the scanner head. Standard Laser scanners will scan the bar codes you see in the stores (6-10 milX dim.) from 2 inches to 8 inches from the item.
CCD scanners look like a vacuum nozzle in shape and are described as the inexpensive laser scanner. A CCD scanner is non-contact and contact in that you just have to place the scan head over the bar code to scan. The distance is 0 to 3 inches.
Long range scanners in warehouse applications, will scan (40-60 mil) from 20 inches to 120 inches. Extra Long Range scanners will scan a 55 mil bar up to 180 inches in the correct light. Further than that requires reflective label material.