Example: Parsing Input Data Using strread :: Serial Port I/O (External Interfaces)

External Interfaces

Example: Parsing Input Data Using strread

This example illustrates how to use the strread function to parse and format data that you read from a device. strread is particularly useful when you want to parse a string into one or more variables, where each variable has its own specified format.

The instrument is a Tektronix TDS 210 two-channel oscilloscope connected to the serial port COM1.

Create a serial port object - Create the serial port object s associated with serial port COM1.

```
s = serial('COM1');
```

Connect to the device - Connect s to the oscilloscope. Because the default value for the ReadAsyncMode property is continuous, data is asynchronously returned to the input buffer as soon as it is available from the instrument.

```
fopen(s)
```

Write and read data - Write the RS232? command to the instrument using fprintf, and then read back the result of the command using fscanf. RS232? queries the RS-232 settings and returns the baud rate, the software flow control setting, the hardware flow control setting, the parity type, and the terminator.

fprintf(s,'RS232?')
data = fscanf(s)
data =
9600;0;0;NONE;LF

Use the strread function to parse and format the data variable into five new variables.

[br,sfc,hfc,par,tm] = strread(data,'%d%d%d%s%s','delimiter',';')

br =
        9600
sfc =
     0
hfc =
     0
par = 
    'NONE'
tm = 
    'LF'

Disconnect and clean up - When you no longer need s, you should disconnect it from the instrument, and remove it from memory and from the MATLAB workspace.

```
fclose(s)
delete(s)
clear s
```

Example: Writing and Reading Text Data Example: Reading Binary Data