SATO CL4NX Programming Reference Manual page 562

(3) Status 3, Status 5/ENQ response mode (1 port connection)
The printer returns ACK by receiving the print request command sent from the host, and returns the printer status by
receiving the status request command (ENQ:05H)
CONNECT
(Port 1024 or Port 9100)
CONNECT SUCCESS
Connection
Status request
(Port 1025 or Port 9100)
(ENQ "05H")
(Port 1025 or Port 9100)
CLOSE
(Port 1024 or Port 9100)
CONNECT END
Host
Printer
LISTEN
ACCEPT
The latest printer status
Printer status
CLOSE
LISTEN
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