Because the status sent from the printer has certain fixed bits, it is possible to identify to which command the status
belongs.
When using ASB (Automatic Status Back), however, the first byte of ASB should be checked, and then the three
consecutive bytes except for XOFF should be treated as ASB data.
Identification of Send Status
Command and Function Status
GS I ＜0**0****＞Ｂ
GS r ＜0**0****＞Ｂ
XON ＜00010001＞Ｂ
XOFF ＜00010011＞Ｂ
DLE EOT ＜0**1**10＞Ｂ
ASB (1st byte) ＜0**1**00＞Ｂ
ASB (2nd - 4th bytes) ＜0**0****＞Ｂ