TallyGenicom 2440 User Guide
Interfaces
Serial interface (option)
B-11
1
Data received when DSR is low is considered invalid and will be discarded.
2
CTS is required in order for the XON/XOFF protocol to work, because CTS is
required in order for data transmission to occur. After Reset, when CTS is detected,
an XON will be sent.
required in order for data transmission to occur. After Reset, when CTS is detected,
an XON will be sent.
3
However, PC is not required to detect this initial XON before transmitting data to
Printer.
Printer.
4
Printer transmits an XOFF to indicate to PC that the receive buffer is full.
5
An XON will be transmitted to PC when buffer space is again available, and the
printer is ready to receive more data.
printer is ready to receive more data.
6
And if data is sent from Host more after outputting XOFF, XOFF will be output
every 16bytes receiving.
every 16bytes receiving.
XON/XOFF:
INIT
RTS
DSR
1
Receive Data
Valid
CTS
2 XON XOFF XON
XMT Data
3 4
Receive Data