Telepen
Telepen provides three coding schemes, each having its own pair of start and stop characters and an optional Mod 127 check digit:
Full ASCII – encodes the lower 128 ASCII characters
Compressed Numeric – where the encoding starts in compressed numeric mode (encoding two digits per group of bars) and may be followed by ASCII encoding. This scheme is for encoding an even number of digits. If an odd number of digits is to be encoded then either a switch from Compressed numeric to ASCII is required before the final digit or the string of digits must be prefixed with a 0.
ASCII – where the encoding starts in full ASCII mode and is followed by digits in compressed numeric encoding.
Telepen
Telepen N
The switch from ASCII to Compressed numeric (or vice versa) is accomplished by the insertion of an ASCII DLE character, but this is permitted only once in any symbol.
The dLSoft barcode library provides standard Telepen (in which the above are followed), Telepen N (which uses the above scheme but forces the full ASCII start and stop bars), and Telepen A (which encodes all data as ASCII without compressed numeric). The Telepen ASCII mode provides the full ASCII character set. Codes below 32 (space) may be entered as <ALT>0XYZ, where XYZ is the 3 digit ASCII code +128. The ASCII ESC character required on some Telepen Numeric systems as the first character may be obtained by checking the EXTRA1 checkbox in applications, or setting the flags parameter bit DL_FLAG_EXTRA1 (bit 4 of the flags variable) or BarCode.Extra1 in the OCX. Normally a switch from Compressed numeric to ASCII is used to handled odd length digit strings, but by checking the EXTRA2 checkbox in applications, or setting the flags parameter bit DL_FLAG_EXTRA2 (bit 4 of the flags variable) or BarCode.Extra1 in the OCX, the library will prefix the digits with a 0 to make the total number of digits even.
UPC