fgetl (serial)
(To be removed) Read line of ASCII text from device and discard terminator
This serial object function will be removed in a future release. Use
serialport
object functions instead. For more information on updating your code, see Version History.
Syntax
tline = fgetl(obj)
[tline,count] = fgetl(obj)
[tline,count,msg] = fgetl(obj)
Description
tline = fgetl(obj) reads one line of ASCII
text from the device connected to the serial port object, obj, and
returns the data to tline. This returned data does not include the
terminator with the text line. To include the terminator, use
fgets.
[tline,count] = fgetl(obj) returns the
number of values read to count, including the terminator.
[tline,count,msg] = fgetl(obj) returns a
warning message to msg if the read operation was unsuccessful.
Examples
On a Windows® platform, create the serial port object s, connect
s to a Tektronix® TDS 210 oscilloscope, and write the RS232? command with
the fprintf function. RS232? instructs the scope
to return serial port communications settings.
s = serial('COM1'); fopen(s) fprintf(s,'RS232?')
Because the default value for the ReadAsyncMode property is
continuous, data is automatically returned to the input
buffer.
s.BytesAvailable
ans =
17
Use fgetl to read the data returned from the previous write
operation, and discard the terminator.
settings = fgetl(s)
settings = 9600;0;0;NONE;LF
length(settings)
ans =
16
Disconnect s from the scope, and remove s from
memory and the workspace.
fclose(s)
delete(s)
clear s
Tips
Before you can read text from the device, it must be connected to
obj with the fopen function. A connected
serial port object has a Status property value of
open. An error is returned if you attempt to perform a read
operation while obj is not connected to the device.
If msg is not included as an output argument and the read operation
was not successful, then a warning message is returned to the command line.
The ValuesReceived property value is increased by the number of
values read – including the terminator – each time fgetl is
issued.
Note
You cannot use ASCII values larger than 127 characters. The function is limited to 127 binary characters.
Rules for Completing a Read Operation with fgetl
A read operation with fgetl blocks access to the MATLAB® command line until:
The terminator specified by the
Terminatorproperty is reached.The time specified by the
Timeoutproperty passes.The input buffer is filled.
Note
You cannot use ASCII values larger than 127 characters. The function is limited to 127 binary characters.