
 20 
SCANNER OPERATION 
Visual Indicators  
The QuantumT is equipped with a blue and white LED that indicates the 
scanner’s state and the status of the current scan when the unit is in operation. 
Figure 13.  Speaker Location and LED Location 
No LEDs 
The LEDs will not be illuminated if the scanner is not receiving power from the 
host or transformer.  They are also not illuminated when the laser is turned off 
for any reason. 
Steady Blue 
When the laser is active, the blue LED is illuminated.  The blue LED will remain 
illuminated until the laser is deactivated.  
Steady Blue and Single White Flash 
When the scanner successfully reads a bar code, the white LED will flash and 
the scanner will beep once.  If the white LED does not flash or the scanner 
does not beep once, then the bar code has not been successfully read. 
Steady White and Blue 
After a successful scan, the scanner transmits the data to the host device.  
Some communication modes require that the host inform the scanner when 
data is ready to be received.  If the host is not ready to accept the information, 
the scanner’s white LED will remain on until the data can be transmitted. 
Alternating Blue and White Flashes 
This indicates the scanner is in configuration mode.  A razzberry tone indicates 
that an invalid bar code has been scanned in this mode.  
Steady White, Blue Off 
This indicates the scanner may be waiting for communication from the host.