Solution(s):

Null characters may be encoded in Code 39, Code 128 and most 2D barcode types such as Data Matrix. However, the null character represents the end of a data string in most applications. Therefore, any data encoded after it will usually be truncated by the barcode scanner or the application itself.

In Data Matrix, the format ~dNNN represents the ASCII character encoded where NNN is the ASCII number. For example, ~d009 encodes a tab and ~d000 encodes the null character.