Handshaking protocol
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
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 transfer after X-off signal
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.