MFJ-1270C/1274C MANUAL ADVANCED OPERATION
Page 58
that the output stop and another special character (usually <CTRL-Q>) to restart
output. Hardware flow control may be used if both computers use the C,ear To
Send (CTS) and Data Terminal Ready (DTR) lines of the RS-232C standard.
Data is also halted if you press the space bar while in command mode. Press
<CR> to resume.
Some commonly used terminal programs and file transfer programs for home
computers do not implement flow control in software, and many serial ports do
not support hardware flow control. Although the DTR and CTS lines appear at
the connector, they may not be used on some computers unless the software
reads the state of the CTS line. If you find that the MFJ TNC seems to lose data
during file transfers, you should immediately suspect a flow control problem.
XON/XOFF Flow Control
If you are using a terminal (rather than a computer) or if your computer does not
support DTR/CTS flow control, you should use XON/XOFF flow control, which
is enabled by setting XFLOW ON. The special flow control characters are set
to <CTRL-S> and <CTRL-Q> by default, but they may be changed.
The commands XON and XOFF set the characters which will be sent to
the
terminal by
the MFJ TNC, and the commands START and STOP set the
characters to be sent to
the MFJ TNC by the terminal. Your computer may
receive as many as 4 characters from the MFJ TNC after sending a STOP
character, since some characters may already be "in route" through serial I/O
chips.
If you send a STOP (START) character to the MFJ TNC when it is already
stopped (started), the character will be ignored. If the STOP and START
character are the same character, this character will "toggle" the output, turning
it off if it is on, and on if it is off.
You can disable XON/XOFF flow control in one direction only by setting the
appropriate flow control characters to 0. If you do this, the MFJ TNC will
automatically use CTS flow control to stop input from the terminal. XON/XOFF
flow control is normally disabled in Transparent Mode, since all characters are
treated as data. If you cannot use DTR/CTS flow control, you may enable the
XON and XOFF characters (the commands from the MFJ TNC to the terminal)
by setting TXFLOW ON and XFLOW ON. The START and STOP characters
(the commands to the MFJ TNC from the terminal) can be enabled in
To Next Page
Loading...
