Create a connection to a serial port device. In this example, the serial port at COM3 is connected to a loopback device.

device = serialport("COM3",9600)

device = 

  Serialport with properties:

                 Port: "COM3"
             BaudRate: 9600
    NumBytesAvailable: 0

  Show all properties, functions

Check the default ASCII terminator.

device.Terminator

ans = 

    "LF"

Set the terminator to "CR" and write a string of ASCII data. The writeline function automatically appends the terminator to the data.

configureTerminator(device,"CR")
writeline(device,"hello")

Write another string of ASCII data with the terminator automatically appended.

writeline(device,"world")

Since the port is connected to a loopback device, the data you write to the device is returned to MATLAB. Read a string of ASCII data. The readline function returns data until it reaches a terminator.

readline(device)

ans = 

    "hello"

Read a string of ASCII data again to return the second string that you wrote.

readline(device)

ans = 

    "world"

Clear the serial port connection.

clear device