Epson C8230 User Manual

DTR and X-on/X-off handshaking protocols can be

performed under either RS-232D or 20mA Current Loop

transmission.

X-on/X-off protocol is a system in which the printer
transmits a code to the computer to indicate that it
cannot accept more data, and a second code when it is

once again ready.

The C82305* /C82306* interface card sends an
X-on < 11 

> H 

code when it is ready to receive data, and

an X-off < 13 > 

H 

when it is busy. The X-on/X-off signals

may be transmitted from the TXD terminal at RS-232D
signal levels, or through the TTY-TXD terminal at 20
mA Current Loop levels.

After the X-on flag has been set, data can be accepted

up to the maximum capacity of the buffer.

•  Transmit timing of X-off signal

The X-off signal is transmitted when the vacant area
in the buffer drops below the specified value

(typically 256 bytes; refer to your printer manual).

Data can be sent to the printer even after the X-off
signal is transmitted as long as sufficient room for
data remains in the buffer. However, if the

transmitted data exceeds the vacant area in the
buffer, it will be discarded.

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