Compuprint MDP40B Programmer Manual - Manual (Page 118)

B-11
UPC-E DC4 DC4 ESC! n 4 p EM
UPC-E bar code data fields contain numeric data only: question marks will be
printed in place of HRC string otherwise, if possible.
If 12-digit strings will be received within a DC4 DC4 ESC (... EM control
sequence and o check-digit option field is missing or takes values 0 or 2, the
symbol is compressed as received to an 8-digit string and encoded, even
though this may affect its readability; if o check digit option field takes values
1 or 3, the 12
th digit is matched against the internally generated check digit.
The question marks will be printed in place of HRC string when mismatch is
found, if possible.
If 11-digit strings will be received and o check digit field is missing or takes
values 0 or 2, question marks will be printed in place of HRC string, when
possible; if o field takes value 1, the 12
th digit is inserted by the printer as
result of the internally available algorithm applied to the received string.
If 10-digit strings will be received and o check-digit is missing or takes NULL
value, question marks will be printed in place of HRC string, if possible; if o
field takes value 1, a default 0 System-Digit will be automatically inserted by
the printer and the 12
th digit will also be inserted as result of he internally
available algorithm applied to the final string.
If the final UPC-A string cannot be compressed to an 8-digits string or the
received System-Digit is different than 0 or 1, question marks will be printed
in place of HRC string, if possible.