2
Theory of Operation
The scanning process begins once the infrared (IR) device located behind the
window senses an object in the scan field. The IR sensor is active as long as
power is applied to the unit. When the IR sensor detects an object, the display
reads "READY TO SCAN" and the cursor flashes to show that the laser is
"ON." When the laser decodes a bar code, the scanner transmits the data to the
host system and then "beeps" to indicate the decoding is complete. The IR
sensing range can be programmed for two ranges.
Short Range Activation:
The IR signal initiates the scan process if it senses
an object anywhere from the face of the window
out to approximately 4" to 7".
Long Range Activation:
The IR signal initiates the scan process if it senses
an object anywhere from the face of the window
out to approximately 9" to 13".
If the object is removed
from the field during the scanning process, the laser
turns off.
However,
if the object stays in the field
, the laser remains on for up to 2.5
seconds trying to detect another bar code. If the scanner does not detect a bar
code, the laser turns off. To reactivate the scanning sequence, remove the
object and present another.
If the same symbol stays in the field after a successful scan
, the laser stays on
for approximately 4 seconds and then turns off. This prevents unintentional
reads of the same bar code. To read the same symbol more than once, remove
the object from the scan field for approximately 1 second and then present the
symbol again.
