
 28 
T
ROUBLESHOOTING 
G
UIDE
Symptoms  Possible Causes  Solution 
The unit powers 
up, but does not 
scan and/or 
beep. 
The bar code being 
scanned does not 
satisfy the configured 
criteria for character 
length lock or minimum 
length. 
Verify that the bar code being 
scanned falls into the configured 
criteria. 
The scanner defaults to a minimum 
of 3 character bar code. 
The following item is only relevant for RS232 and Serial Emulation USB interfaces. 
The unit scans a 
bar code, but 
locks up after the 
first scan and the 
red* LED stays on.
The unit is configured 
to support some form 
of host handshaking 
but is not receiving the 
signal. 
If the unit is setup to support 
ACK/NAK, RTS/CTS, XON/XOFF or 
D/E, verify that the host cable and 
host are supporting the handshaking 
properly. 
The unit scans, 
but the data 
transmitted to the 
host is incorrect. 
The unit’s data format 
does not match the 
host system’s 
requirements. 
Verify that the unit’s data format 
matches that required by the host.  
Make sure that the unit is connected 
to the proper host port. 
The bar code may 
have been printed 
incorrectly. 
The unit is not 
configured correctly for 
the type of bar code 
being scanned. 
Check if it is a check digit/character 
or border problem. 
The unit beeps at 
some bar codes 
but NOT for 
others of the 
same bar code 
symbology.  The minimum symbol 
length setting does not 
work with the bar code. 
Check if the correct minimum 
symbol length is set. 
The unit scans 
the bar code but 
there is no data. 
The unit’s configuration 
is not correct. 
Make sure the scanner is configured 
for the appropriate mode.  
The host is 
receiving data 
but the data does 
not look correct. 
The scanner and host 
may not be configured 
for the same interface 
parameters. 
Check that the scanner and the host 
are configured for the same 
interface parameters. 
Characters are 
being dropped. 
Inter-character delay 
needs to be added to 
the transmitted output. 
Add some inter-character delay to 
the transmitted output by using the 
MetroSelect Single-Line 
Configuration Guide. 
*
  In some custom units, the standard green LED has been replaced with a blue LED and the red 
LED has been replaced with a white LED.