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BEEPER/LED
VIDEO
LASER ON
+VCC
This scanner input drives the green decoding
LED, and the beeper in the scanner. The
LED turns on when a positive current is
applied to the pin. The beeper sound is
obtained pulsating this current at a frequency
of about 2 kHz. The maximum voltage that
can be applied to this input is 5 Vdc.
This "open collector" scanner output is
electrically
supplies a series of pulses the length of
which are proportional to the width of the
elements within the barcode read. A low
output level corresponds to a bar. The
frequency of the pulses depends on the
density of the code, the distance from code
and the programmed output scan frequency
(see the following figure Video and Scan
signals).
A positive voltage between 4.75 and 5 Vdc is
applied to this input by the decoder when the
decoding logic senses the trigger is pressed;
this causes the laser to start scanning and
the red LED to turn on.
This input must be connected to the positive
pin of the supply voltage (4.75 - 14 Vdc).
When the LASER ON pin is positive, all the
current necessary to power the scanner flows
through +VCC.
CODE
VIDEO
SCAN
identical
to the barcode.
Video and Scan Signals
It
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