Bar code troubleshooting tips

Bar codes will not read

Are you using the correct function with the correct font name?

Each font is designed to only be used with a specific function.

See Bar code functions and Bar code font name and font size to use.

Are you using the correct font size?

See Bar code font name and font size to use.

Does your bar code reader have this type of bar code enabled?

Most bar code readers can enable or disable each type of bar code. You may need to enable the type of bar code you want to read. See your bar code reader manual.

Code 39

My bar codes contain lowercase letter and I get strange characters when I read.

Lowercase letters and some other characters are not in the normal Code 39 character set, lowercase letters are in the 'extended' character set.

You are using CIA_CODE39( ) which produces extended characters, but your bar code reader is not configured correctly.

Answer: Configure your bar code reader to recognise Extended Code 39 (sometime referred to as 'Full ASCII'). Read the user manual which arrived with your bar code reader.

ITF (Interleaved 2-of-5)

Why do some of my bar codes have a leading zero 0 that is not in the original data.

This type of bar code must be an even length (2,4,6,...), so a zero is added to the front of data that is an odd length (3,5,7,...).

TIP: If you want all bar codes to be the same length, then pad the data with zeros to same length, like so;


becomes like this when padded with zeros;


The result is bar codes which have the same length.

Code 128

Why does the length of bar codes different, if they contain the same number of characters?

If your data contains digits, and the digits are in a sequence of 4 or more digits together, then some Code 128 functions will automatically optimise the Code 128 bar code. The length of optimised bar codes is reduced, which is an advantage in most applications.

This is because pairs of digits can be stored using just one character from special character set C.

TIP: If your data contains a mixture of letters and numbers, and you are concerned that some data may cause the bar code to print past the edge of the label or page, then do the following. Print a test bar code, using data which contains no numbers - this will produce the longest possible bar code.


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