Epson GT-6500 EN - Manual (Page 104)

ESC f Request extended status
Format: EXT
Command:ASCII: ESC f
Decimal: 27 102
Hexadecimal: 1B 66
Parameter: (none)
Handshaking:
1 ESC f command
2 Data block
Explanation:
When this command is received, the scanner sends a data block
indicating the current status of the scanner and any optional
equipment. The current status can be determined by reading the flags
of the status byte and the following bytes of status data.
3-10 Command Reference