[ under construction ]


Glossario dei termini AUTO-ID



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D

data collection
Si intende l'azione di acquisire delle informazioni o dati generalmente con dispositivi automatici in grado di accumulare o trasmettere immediatamente tali dati, nel settore della identificazione automatica tale termine e' riferito ai dei dispositivi in grado di leggere il codice a barre, magnetico o RF-ID.
data terminal equipment (DTE)
Equipment comprising the data source, data link or both.
dead zone
An area, within a scanner's field of view specular reflection may prevent a successful decode.
( See specular reflection )
densitometer
An instrument that measures the degree to which light is transmitted through or reflected from a material by illuminating the area to be measured with the light at a known wavelength. A calibrate photometer receives the light and measures its value. Results of the measurement may be displayed as percentage reflectance or density.
decoder
An electronic assemblywhich translates the proportional electrical signals from a scanner into recognisable or computer compatible data. The decoder performs checks on the electronic signal to validate it as meaningful ( i.e. that quiet zones precede the signal representing the bar code ), and processes the signal through a decode algorethm designed to detect errors in the signal. Depending on the equipment the decoder and scanner can be separate devices or be integral parts of the same device. In the former the output from the scanner is an electrical signal representing the reflectance of the bar code; in the second case the output from the integrated device is the decoded data. Some decoders are microprocessor controlled and can carry out limited data processing operations of various tyoes or store data for batch transmission.
depth of field
The range of distances between minimum and maximum over which a scanner can reliably read a symbol. Also called "decode zone"
discrete code
A bar code in which each character is separated by an intercharacter gap or space which does not contain information.