CONFIDENTIAL
Paper roll Customize commands GS ( C
Ver. 10.0 1 p. 557
■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:
(*1) Response code
(*2) Processing according to response (unsent data exists, identified by send data set “Identification
status”)
■Processing the codes except for ACK, NAK, and CAN performs the same processing as CAN.
Step Host process Printer process
1 Send GS(C <Function 2>. Start processing of Function 2. (Read specified record back to host.)
2 Receive data from printer. Send data in memory.
3 Send response code. (*1) Continue processing (*2) (*3) according to response.
ASCII Hex Decimal Request
ACK 06 6 Send next data.
NAK 15 21 Resend previously sent data.
CAN 18 24 Cancel send process.
Response code Process
ACK Start send processing for next data.
NAK Resend previously sent data.
CAN End processing for this command.