Toshiba V.90 - Manual (Page 75)

MNP and V.42
Flow control
56
XON/XOFF flow control (software)
Flow control is performed by sending XON and XOFF control
codes in the data stream. The XOFF code makes a transmission
halt request. The XON code makes a transmission restart request.
Since these two codes, XON and XOFF, are used as flow control
characters, binary data that includes these two codes cannot be
transmitted or received.
CTS/RTS two-way flow control (hardware)
Flow control is performed by turning on and off the control lines
CTS (clear to send) and RTS (request to send) between the
modem and the computer. A transmission halt or restart request is
made from the modem to the computer using the CTS signal.
A transmission halt or restart request is made from the personal
computer to the modem using the RTS signal.
Commands (\Qn, &Kn)
Select flow control between the modem and computer (serial port)
as follows:
❖ When CTS/RTS flow control is supported by the
communication software
\Q3, &K3 Communication in reliable mode or normal mode
❖ When XON/OFF flow control is only supported by the
communication software
\Q1, &K4 Communication in reliable mode or normal mode
For details, refer to “AT Commands” on page 13 .
Modem port flow control
Modem port flow control refers to flow control between the
modems of the local station and remote station.