Epson TM-T88III Programming Manual page 557

C O N F I D E N T I A L
When communication with the printer uses XON/XOFF control with serial interface, the XOFF code may
interrupt the "Header to NUL" data string.
The transmission information for each function can be identified to other transmission data according to
specific data of the transmission data block. When the header transmitted by the printer is [hex = 37H/
decimal =55], treat NUL [hex = 00H/decimal =0] as a data group and identify it according to the
combination of the header and the identifier.
[Notes for ESC/POS Handshaking Protocol]
Use ESC/POS Handshaking Protocol below for Functions 2 and 5:
Step Host process
1
2
3
(*1)
ASCII
ACK
NAK
CAN
(*2)
status")
Response code
ACK
NAK
CAN
Processing the codes except for ACK, NAK, and CAN performs the same processing as CAN.
Paper roll Customize commands
Send GS ( C <Function 2>.
Receive data from printer.
(*1)
Send response code.
Response code
Hex Decimal Request
06 6 Send next data.
15 21 Resend previously sent data.
18 24 Cancel send process.
Processing according to response (unsent data exists, identified by send data set "Identification
Process
Start send processing for next data.
Resend previously sent data.
End processing for this command.
GS ( C
Printer process
Start processing of Function 2. (Read specified record back to host.)
Send data in memory.
(*2) (*3)
Continue processing according to response.
Ver. 10.01 p. 557