Abstract: A hardware identification system is provided in a bar code reading arrangement including a main body and a plurality of modular detachable scanning heads connectable to the main body dependent on the application desired for the reader. Each of the heads includes a voltage divider dividing identification voltage and the main body includes a microprocessor including an analog to digital converter which reads the identification voltage, converts it to a digital signal and compares the identification voltage against a look-up table of identification voltages and their associated hardware element to identify the module type. Alternatively, or in addition, the module may be similarly configured to identify the main body by virtue of an identification voltage defined by a voltage divider in the main body. Alternatively the hardware identification system includes an electronic subassembly such as a PC board used for example in computer systems for automatic identification of hardware.

Abstract: An optical scanning system is provided for producing a signal representative of a spatial distribution of indicia having different degrees of reflectivity to light, such as a bar code. The system includes an optical scanner for scanning beam of light over the spatial distribution of indicia and for producing an electrical signal corresponding to changes in the degree of reflectivity of the indicia. A digitizer, responsive to detections in a predetermined characteristic of the produced electrical signal is provided. The digitizer converts the detections into digital words, such digital signals having a plurality of bits. The digitizer includes a timing generation circuit for producing a pulse in response to each one of the detections with a time duration representative of the degree of reflectivity of the indicia as the beam of light. A decoder converts the time duration of the pulse into the digital word having a plurality of bits. An enhancement filter is also disclosed.