2
Theory of Operation
When connected to a decoder/controller and to the signals as defined in the pin
assignment sections, the IS4210 and IS4213 scanners will operate as follows.
The scanning process initiates by an infrared (IR) device located behind the
window. The IR sensor is active as long as the power is applied to the unit.
When the IR sensor detects an object, the green LED will flash. When the
laser decodes a bar code, the scanner transmits the data to the host system and
then " beeps" to show 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 and the scanner reenters "standby" mode.
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 scanner reenters "standby" mode. 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 uninten-tional
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.
