Epson TM-T90 Printer User Manual


 
CONFIDENTIAL
Paper roll Miscellaneous commands GS ( H
Ver. 10.01 p. 426
Notes for response transmission process
When the host PC isn’t able to receive when the response is transmitted, the response is reserved and the
printer starts processing the next data. The reserved response is processed again at the next time for
transmitting responses.
When specifying any response with a serial interface, make sure that the host PC is able to receive data.
When host is unable to receive data, responses cannot be received correctly.
When operating with a parallel interface, the data sent by this function (starting with Header and ending
with NUL), as with other data, is first stored in the send buffer, then output in sequential order when the
host computer changes to the reverse mode. Note that the send buffer capacity is 99 bytes, and any data
exceeding this volume limit will be lost; therefore, when using this command, it is important to configure
the operation so that the host computer’s change to the reverse mode and the subsequent status send/
receive process is performed quickly.
The printer enters the BUSY state just before the data header is sent. After NUL has been sent, the printer
enters the READY state (except when other factors cause it to enter the BUSY state).
When communication with the printer uses XON/XOFF control with a serial interface, the XOFF code may
interrupt the “Header to NUL” data string.
The response 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.