fconfigure.n

tcl是工具命令语言

.VS 8.4
.SH "SERIAL PORT CONFIGURATION OPTIONS"
.PP
If \fIchannelId\fR refers to a serial port, then the following
additional configuration options are available on Windows and
Unix systems with a POSIX serial interface:

.TP
\fB\-mode\fR \fIbaud\fB,\fIparity\fB,\fIdata\fB,\fIstop\fR
.
This option is a set of 4 comma-separated values: the baud rate, parity,
number of data bits, and number of stop bits for this serial port.  The
\fIbaud\fR rate is a simple integer that specifies the connection speed.
\fIParity\fR is one of the following letters: \fBn\fR, \fBo\fR, \fBe\fR,
\fBm\fR, \fBs\fR; respectively signifying the parity options of ``none'',
``odd'', ``even'', ``mark'', or ``space''.  \fIData\fR is the number of
data bits and should be an integer from 5 to 8, while \fIstop\fR is the
number of stop bits and should be the integer 1 or 2.

.TP
\fB\-handshake\fR \fItype\fR
.
(Windows and Unix). This option is used to setup automatic handshake
control. Note that not all handshake types maybe supported by your operating
system. The \fItype\fR parameter is case-independent.

If \fItype\fR is \fBnone\fR then any handshake is switched off.
\fBrtscts\fR activates hardware handshake. Hardware handshake signals
are described below.
For software handshake \fBxonxoff\fR the handshake characters can be redefined
with \fB-xchar\fR.
An additional hardware handshake \fBdtrdsr\fR is available only under Windows.
There is no default handshake configuration, the initial value depends
on your operating system settings.
The \fB-handshake\fR option cannot be queried.

.TP
\fB\-queue\fR
.
(Windows and Unix). The \fB-queue\fR option can only be queried.
It returns a list of two integers representing the current number
of bytes in the input and output queue respectively.

.TP
\fB\-timeout\fR \fImsec\fR
.
(Windows and Unix). This option is used to set the timeout for blocking
read operations. It specifies the maximum interval between the
reception of two bytes in milliseconds.
For Unix systems the granularity is 100 milliseconds.
The \fB-timeout\fR option does not affect write operations or
nonblocking reads.
This option cannot be queried.

.TP
\fB\-ttycontrol\fR \fI{signal boolean signal boolean ...}\fR
.
(Windows and Unix). This option is used to setup the handshake
output lines (see below) permanently or to send a BREAK over the serial line.
The \fIsignal\fR names are case-independent.
\fB{RTS 1 DTR 0}\fR sets the RTS output to high and the DTR output to low.
The BREAK condition (see below) is enabled and disabled with \fB{BREAK 1}\fR and
\fB{BREAK 0}\fR respectively.
It's not a good idea to change the \fBRTS\fR (or \fBDTR\fR) signal
with active hardware handshake \fBrtscts\fR (or \fBdtrdsr\fR).
The result is unpredictable.
The \fB-ttycontrol\fR option cannot be queried.

.TP
\fB\-ttystatus\fR
.
(Windows and Unix). The \fB-ttystatus\fR option can only be
queried.  It returns the current modem status and handshake input signals
(see below).
The result is a list of signal,value pairs with a fixed order,
e.g. \fB{CTS 1 DSR 0 RING 1 DCD 0}\fR.
The \fIsignal\fR names are returned upper case.

.TP
\fB\-xchar\fR \fI{xonChar xoffChar}\fR
.
(Windows and Unix). This option is used to query or change the software
handshake characters. Normally the operating system default should be
DC1 (0x11) and DC3 (0x13) representing the ASCII standard
XON and XOFF characters.

.TP
\fB\-pollinterval\fR \fImsec\fR
.
(Windows only). This option is used to set the maximum time between
polling for fileevents.
This affects the time interval between checking for events throughout the Tcl
interpreter (the smallest value always wins).  Use this option only if
you want to poll the serial port more or less often than 10 msec
(the default).

.TP
\fB\-sysbuffer\fR \fIinSize\fR
.TP
\fB\-sysbuffer\fR \fI{inSize outSize}\fR
.
(Windows only). This option is used to change the size of Windows
system buffers for a serial channel. Especially at higher communication
rates the default input buffer size of 4096 bytes can overrun
for latent systems. The first form specifies the input buffer size,
in the second form both input and output buffers are defined.

.TP
\fB\-lasterror\fR
.
(Windows only). This option is query only.
In case of a serial communication error, \fBread\fR or \fBputs\fR
returns a general Tcl file I/O error.
\fBfconfigure -lasterror\fR can be called to get a list of error details.
See below for an explanation of the various error codes.

.SH "SERIAL PORT SIGNALS"
.PP
RS-232 is the most commonly used standard electrical interface for serial
communications. A negative voltage (-3V..-12V) define a mark (on=1) bit and
a positive voltage (+3..+12V) define a space (off=0) bit (RS-232C).  The
following signals are specified for incoming and outgoing data, status
lines and handshaking. Here we are using the terms \fIworkstation\fR for
your computer and \fImodem\fR for the external device, because some signal
names (DCD, RI) come from modems. Of course your external device may use
these signal lines for other purposes.
.RS
.IP \fBTXD(output)\fR
\fBTransmitted Data:\fR Outgoing serial data.
.IP \fBRXD(input)\fR
\fBReceived Data:\fRIncoming serial data.
.IP \fBRTS(output)\fR
\fBRequest To Send:\fR This hardware handshake line informs the modem that
your workstation is ready to receive data. Your workstation may
automatically reset this signal to indicate that the input buffer is full.
.IP \fBCTS(input)\fR
\fBClear To Send:\fR The complement to RTS. Indicates that the modem is
ready to receive data.
.IP \fBDTR(output)\fR
\fBData Terminal Ready:\fR This signal tells the modem that the workstation
is ready to establish a link. DTR is often enabled automatically whenever a
serial port is opened.
.IP \fBDSR(input)\fR
\fBData Set Ready:\fR The complement to DTR. Tells the workstation that the
modem is ready to establish a link.
.IP \fBDCD(input)\fR
\fBData Carrier Detect:\fR This line becomes active when a modem detects
a "Carrier" signal.
.IP \fBRI(input)\fR
\fBRing Indicator:\fR Goes active when the modem detects an incoming call.
.IP \fBBREAK\fR
A BREAK condition is not a hardware signal line, but a logical zero on the
TXD or RXD lines for a long period of time, usually 250 to 500
milliseconds.  Normally a receive or transmit data signal stays at the mark
(on=1) voltage until the next character is transferred. A BREAK is sometimes
used to reset the communications line or change the operating mode of
communications hardware.
.RE

.SH "ERROR CODES (Windows only)"
.PP
A lot of different errors may occur during serial read operations or during
event polling in background. The external device may have been switched
off, the data lines may be noisy, system buffers may overrun or your mode
settings may be wrong.  That's why a reliable software should always
\fBcatch\fR serial read operations.  In cases of an error Tcl returns a
general file I/O error.  Then \fBfconfigure -lasterror\fR may help to
locate the problem.  The following error codes may be returned.
.RS
.IP \fBRXOVER:\fR
Windows input buffer overrun. The data comes faster than your scripts reads
it or your system is overloaded. Use \fBfconfigure -sysbuffer\fR to avoid a
temporary bottleneck and/or make your script faster.
.IP \fBTXFULL\fR
Windows output buffer overrun. Complement to RXOVER. This error should
practically not happen, because Tcl cares about the output buffer status.
.IP \fBOVERRUN\fR
UART buffer overrun (hardware) with data lost.
The data comes faster than the system driver receives it.
Check your advanced serial port settings to enable the FIFO (16550) buffer
and/or setup a lower(1) interrupt threshold value.
.IP \fBRXPARITY\fR
A parity error has been detected by your UART.
Wrong parity settings with \fBfconfigure -mode\fR or a noisy data line (RXD)
may cause this error.
.IP \fBFRAME\fR
A stop-bit error has been detected by your UART.
Wrong mode settings with \fBfconfigure -mode\fR or a noisy data line (RXD)
may cause this error.
.IP \fBBREAK\fR
A BREAK condition has been detected by your UART (see above).
.RE
.VE

.SH "SEE ALSO"
close(n), flush(n), gets(n), puts(n), read(n), socket(n),
Tcl_StandardChannels(3)

.SH KEYWORDS
blocking, buffering, carriage return, end of line, flushing, linemode,
newline, nonblocking, platform, translation, encoding, filter, byte array,
binary