Epson 24-Pin User Manual page 211

c: Control flag
Bit 0 = Check digit
0: The printer does not add a check digit.
1: The printer adds a check digit.
Bit 1 = Human readable character (HRC)
0: The printer adds the HRC.
1: The printer does not add the HRC.
Bit 2 = Position of flag character (for EAN-13 and UPC-A only)
0: Center
1: Under
Bits 3 7 = Not used
Barcode data
Barcode data corresponds to the barcode symbology. The data
number of each barcode type is constant. The barcode is printed
only if the following valid characters are set:
Barcode type
EAN-13
EAN-8
Interleaved 2 of 5
UPC-A
UPC-E
Code 39
Code 128
POSTNET
Number of valid characters 1: Control flag c b0=0
Number of valid characters 2: Control flag c b0=1
Number of valid
characters 1 (HEX)
0D
8
2 to FF
0C
0C or 8
1 to FF
2 to FF
6 or 0A or 0C
Number of valid
characters 2 (HEX)
0C
7
2 to FF
0B
0B or 7
1 to FF
2 to FF
5 or 9 or 0B
C-17
Specifications
C