Metrologic MS7600, Руководство по обслуживанию

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3-1
3 THEORY & OPERATION
3.1 Basic Data Decoding Sectional Summarys
3.1.1 Photodiode (Detector) Summary:
3.1.1.1 Receives the optical signal reflected off the bar code
3.1.1.2
Converts into electrical signal (current) of about 100 nanoamps
3.1.2 Pre-Amplifier Sectional Summary:
3.1.2.1 Part of the Signal processor board, usually contained in a shielded area of the PCB with the Photodiode.
3.1.2.2 Converts the electrical current to a voltage signal
3.1.2.3 Voltage signal is amplified by a factor of 1000
3.1.2.4
Ambient light noise is filtered out. Resultant signal is routed to the mother board to primary signal
processing circuitry
3.1.3 Signal Processor Section Summary:
3.1.3.1 Converts analog waveform into a digital signal that can be used by the microprocessor
3.1.4 Decoder Section Summary:
3.1.4.1 Decoding algorithm decodes digital signals into ASCII characters
FIGURE 2.4-1 VLD LASER AND BARCODE DATA PATHS