Scanning Considerations - Motorola MC9094-KUCHJERA6WR - MC9094-K - Win Mobile 6.1 Professional 624 MHz User Manual

Laser Aiming Pattern (Field of View)
Figure 2-28
Operational Modes
Mobile computers with an integrated imager have three modes of operation: Decode Mode, Pick List Mode and
Image Capture Mode. All modes are activated by pulling the trigger or pressing the Scan button.
Decode Mode
This mode allows the user to decode a bar code when a single bar code in the mobile computer's field of view.
In this mode the Imager attempts to locate and decode enabled bar codes within its field of view. The Imager
remains in this mode as long as the trigger is pulled, or until a bar code is decoded.
Pick List Mode
Pick List mode allows the user to selectively decode a bar code when more than one bar code is in the mobile
computer's field of view. By moving the aiming crosshair over the wanted bar code the user can selectively
read only the required bar code. This feature is particularly valued for pick lists containing multiple bar codes
and manufacturing or transport labels containing more than one bar code type (either 1D or 2D).
Image Capture Mode
This mode allows the user to capture an image within the mobile computer's field of view. The user can use the
mobile computer to capture signatures or images of items like damaged boxes.

Scanning Considerations

Typically, scanning is a simple matter of aim, scan/decode and a few quick trial efforts master it. However, two
important considerations can be used to optimize any scanning performance:
Range
•
Any scanning device decodes well over a particular working range — minimum and maximum distances
from the bar code. This range varies according to bar code density and scanning device optics.
Scanning within range brings quick and constant decodes; scanning too close or too far away prevents
decodes. Move the scanner closer and further away to find the right working range for the bar codes being
scanned. However, the situation is complicated by the availability of various integrated scanning modules.
The best way to specify the appropriate working range per bar code density is through a chart called a
decode zone for each scan module. A decode zone simply plots working range as a function of minimum
element widths of bar code symbols.
Angle
•
Scanning angle is important for promoting quick decodes. When laser beams reflect directly back into the
scanner from the bar code, this specular reflection can "blind" the scanner.
To avoid this, scan the bar code so that the beam does not bounce directly back. But don't scan at too
sharp an angle; the scanner needs to collect scattered reflections from the scan to make a successful
decode. Practice quickly shows what tolerances to work within.
Operating the MC909X 2 - 51