Write text to instrument
An interface object.
The string written to the instrument.
C language conversion specification.
Specifies whether data is written synchronously or asynchronously.
cmd to the instrument connected to
The default format is
%s\n. The write operation
is synchronous and blocks the command line until execution is complete.
the string using the format specified by
format is a C language conversion
specification. Conversion specifications involve the
and the conversion characters d, i, o, u, x, X, f, e, E, g, G, c,
and s. Refer to the
I/O format specifications or a C manual for more information.
the string with command-line access specified by
written synchronously and the command line is blocked. If
written asynchronously and the command line is not blocked. If
not specified, the write operation is synchronous.
the string using the specified format. If
written synchronously. If
Create the serial port object
a Windows® machine to a Tektronix® TDS 210 oscilloscope, and
RS232? command with the
the scope to return serial port communications settings.
s = serial('COM1'); fopen(s) fprintf(s,'RS232?') settings = fscanf(s) settings = 9600;1;0;NONE;LF
Because the default format for
the terminator specified by the
was automatically written. However, in some cases you might want to
suppress writing the terminator. To do so, you must explicitly specify
a format for the data that does not include the terminator, or configure
the terminator to empty.
Before you can write text to the instrument, it must be connected
obj with the
A connected interface object has a
open. An error is returned if you attempt
to perform a write operation while
obj is not connected
to the instrument.
ValuesSent property value is increased
by the number of values written each time
An error occurs if the output buffer cannot hold all the data
to be written. You can specify the size of the output buffer with
fprintf function will return an error message
if you set the
flowcontrol property to
a serial object, and a hardware connection is not detected. This occurs
if a device is not connected, or a connected device is not asserting
that is ready to receive data. Check you remote device's status and
flow control settings to see if hardware flow control is causing errors
If you want to check to see if the device is asserting that
it is ready to receive data, set the
Once you connect to the device check the
there is a problem on the remote device side. If
there is a hardware
FlowControl device prepared
to receive data and you can execute
To get a list of options you can use on a function, press the Tab key after entering a function on the MATLAB command line. The list expands, and you can scroll to choose a property or value. For information about using this advanced tab completion feature, see Using Tab Completion for Functions.
By default, text is written to the instrument synchronously
and the command line is blocked until the operation completes. You
can perform an asynchronous write by configuring the
argument to be
async. For asynchronous writes,
BytesToOutput property value
is continuously updated to reflect the number of bytes in the output
The callback function specified for the
is executed when the output buffer is empty.
You can determine whether an asynchronous write operation is
in progress with the
Synchronous and asynchronous write operations are discussed in more detail in Synchronous Versus Asynchronous Write Operations.
A write operation using
The specified data is written.
The time specified by the
For serial port, TCPIP, UDP, and VISA-serial objects, all occurrences
cmd are replaced with
Terminator property value. Therefore, when
using the default format
%s\n, all commands written
to the instrument will end with this property value.
For GPIB, VISA-GPIB, VISA-VXI, and VISA-GPIB-VXI objects, all
replaced with the
EOSCharCode property value
EOSMode property is set to
For example, if
EOSMode is set to
LF, then all occurrences of
replaced with a line feed character. Additionally, for GPIB objects,
the End Or Identify (EOI) line is asserted when the terminator is
The terminator required by your instrument will be described in its documentation.