CODE 39 Barcode Check Digit Calculation
Please note that most barcode printing software is capable of automatically calculating a check digit and inserting it at the end of each barcode value. The CODE39 Mod 43 calculation described below can also be performed manually or by using your own program in rare cases where the barcode printing software being used does not have the option to calculate a CODE39 check digit automatically.    

Check Modulus 43    

Some barcode printing software packages are not capable of including a check digit automatically. The rules for calculating a check digit are as follows:    
 

Message:  12345/ABCDE
Sum of Values:  1+2+3+4+5+40+10+11+12+13+14 = 115
Check Character:  115/43 = 2.6744186
Calculate Check Value: Subtract integer value: (2.6744186 - 2= .6744186) and multiply remainder .6744186 * 43 = 28.999999 round up = 29 or check digit T (see table 1 for corresponding check digit) 
Insert Check Digit:  12345/ABCDET

 
Enabling BSCAN's CRC  

To turn enable BSCAN's check digit reading function, append the line in the [CONFIG1] section of the BSCAN INI file that says BarTypes=CODE39 with ",CRC" so that it reads  

BarTypes=CODE39,CRC 
 

Please note: Be sure that check digits are present before using the CRC parameter with the BarTypes function command. BSCAN will not read barcodes without check digits if the CRC parameter has been added to the BarTypes function command.

 

 

CHECK DIGIT  CHECK VALUE 
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