Epson GT-6500 EN - Manual (Page 148)

ESC m Download color correction
Format: B4 B5
Command: ASCII: ESC m
Decimal: 27 109
Hexadecimal: 1B 60
Parameter: d1, d2, d3, d4, d5, d6, d7, d8, d9
Handshaking:
1 ESC m command
2 ACK code
3 Parameter (d1 ~ d9)
4 ACK code
3-54 Command Reference