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3-6) X-ON / X-OFF Signal Transmission Timing
An X-OFF signal is sent when the printer switches from online to offline.
An X-ON signal is sent when the printer switches from offline to online.
In the Star mode, an X-ON signal is sent every three seconds if memory switch
4-C is set to “1.”
4) Suggestions when memory switch 4-4 is ON [only when using interface specially
designed for for ESC/POS (Dual mode)]
(1) Printing is interrupted in the event of an error, the cover is open, there is no paper,
or paper is advanced by the paper advance switch, but the printer does not switch
to busy status.
(2) When handshake with the printer is executed by this setting, be sure to monitor
the status of the printer using the “GS a” command and its automatic data
transmission function. With this setting, the “GS a” command becomes initial
value setting n = 2, and status is automatically transmitted when online/offline
status changes.
(3) If using DLE EOT or DLE ENQ, do not allow the reception buffer to become full.
• Suggestions when the printer is busy and the host cannot transmit data DLE
EOT or DLE ENQ cannot be used if an error occurs when the printer becomes
busy because the reception buffer is full.
• Suggestions when the printer is busy and the host can transmit data
When the reception buffer becomes full during transmission of bit image data,
if a DLE EOT or DLE ENQ command is used in the bit image data, DLE EOT
or DLE ENQ is processed as bit image data. Data sent when the reception
buffer is full may be discarded.
Usage Example: With a 4K-byte reception buffer, status is checked by “ESC v”
or “ESC u” each time a printing line is sent. The amount of data per printing line
is the amount whereby the reception buffer does not become full.
Printer setting conditions Description of operation
• When in Star mode and memory switch
is set to “0”
• ESC/POS emulation
When available buffer space drops below
256 bytes, exactly one byte is output for
X-OFF. When data in the buffer drops
below 256 bytes, exactly one byte is
output for X-ON.
• When in Star mode and memory switch
is set to “1” When available buffer space drops below
256 bytes, an X-OFF signal is output for
each byte of data received. When data in
the buffer drops below 256 bytes, and X-
ON signal is output.