User guide

2 - 20 MC31XX Series Mobile Computer User Guide
Scanning Considerations
Scanning consists of; aim, scan and decode. Scanning performance can be optimized by considering the range
and the scanning angle:
• 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
The scan angle is important for optimizing decode performance. 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 do not 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.
Imaging
MC31XX with an integrated imager have the following features:
• Omnidirectional (360°) reading of a variety of bar code symbologies, including the most popular linear, postal,
PDF417, and 2D matrix code types.
• The ability to capture and download images to a host for a variety of imaging applications.
• Advanced intuitive laser aiming for easy point-and-shoot operation.
The imager uses digital camera technology to take a digital picture of a bar code, stores the resulting image in its
memory, and executes state-of-the-art software decoding algorithms to extract the data from the image.
Table 2-4 Scan LED Indicators
LED Status Indication
Off Not scanning.
Solid Red Laser enabled, scanning in process.
Solid Green Successful decode.
NOTE Contact the Motorola Enterprise Mobility Support Center if chronic scanning difficulties develop. Decoding of
properly printed bar codes should be quick and effortless.