configureCallback

Set callback function and trigger condition for communication with serial port device

Syntax

configureCallback(device,"terminator",callbackFcn)

configureCallback(device,"byte",count,callbackFcn)

configureCallback(device,"off")

Description

configureCallback(device,"terminator",callbackFcn) sets the callback function callbackFcn to trigger whenever a terminator is available to be read from the specified serial port. The syntax sets the BytesAvailableFcnMode property of device to "terminator" and the BytesAvailableFcn property to callbackFcn.

Set the terminator character using configureTerminator.

configureCallback(device,"byte",count,callbackFcn) sets the callback function callbackFcn to trigger whenever a new count number of bytes are available to be read. The syntax sets the BytesAvailableFcnMode property of device to "byte", the BytesAvailableFcnCount property to count, and the BytesAvailableFcn property to callbackFcn.

configureCallback(device,"off") turns off callbacks. The syntax sets the BytesAvailableFcnMode property of device to "off".

Examples

Set Serial Port Device Callback and Trigger to "terminator" Mode

Create a connection to a serial port device.

device = serialport("COM3",9600)

device = 

  Serialport with properties:

                 Port: "COM3"
             BaudRate: 9600
    NumBytesAvailable: 0

  Show all properties, functions

Set the callback to trigger when a terminator is available to be read.

configureCallback(device,"terminator",@callbackFcn)

View the properties to confirm the change.

device.BytesAvailableFcnMode
device.BytesAvailableFcn

ans = 

    "terminator"


ans =

  function_handle with value:

    @callbackFcn

Turn the callback off.

configureCallback(device,"off")

Verify that the callback is off.

device.BytesAvailableFcnMode

ans = 

    "off"

Set Serial Port Device Callback and Trigger to "byte" Mode

Create a connection to a serial port device.

device = serialport("COM3",9600)

device = 

  Serialport with properties:

                 Port: "COM3"
             BaudRate: 9600
    NumBytesAvailable: 0

  Show all properties, functions

Set the callback to trigger each time 50 new bytes of data are available to be read.

configureCallback(device,"byte",50,@callbackFcn)

View the properties to confirm the change.

device.BytesAvailableFcnMode
device.BytesAvailableFcnCount
device.BytesAvailableFcn

ans = 

    "byte"


ans =

    50


ans =

  function_handle with value:

    @callbackFcn

Turn the callback off.

configureCallback(device,"off")

Verify that the callback is off.

device.BytesAvailableFcnMode

ans = 

    "off"

Read Data from Serial Port Device Using Callback Function

Create a connection to a serial port device.

device = serialport("COM3",9600)

device = 

  Serialport with properties:

                 Port: "COM3"
             BaudRate: 9600
    NumBytesAvailable: 0

  Show all properties, functions

Create a callback function that reads ASCII terminated string data and saves it to the UserData property of device.

function readSerialData(src,evt)
    data = readline(src);
    src.UserData = data;
end

Set the callback to trigger when a terminator is available to be read.

configureCallback(device,"terminator",@readSerialData)

Input Arguments

device — Serial port connection

serialport object

Serial port connection, specified as a serialport object.

Example: configureCallback(device,"byte",128,@callbackFcn) sets the callbackFcn callback to trigger each time 128 bytes of new data are available to be read from the serial port connection device.

count — Number of bytes of data to trigger callback

positive integer value

Number of bytes of available data to trigger the callback, specified as a positive integer value. Set the BytesAvailableFcnCount property using this argument.

Example: configureCallback(device,"byte",128,@callbackFcn) sets the callbackFcn callback to trigger each time 128 bytes of new data are available to be read.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

callbackFcn — Callback function to run when trigger condition is met

function handle

Callback function to run when trigger condition is met, specified as a function handle. The function handle can be a named function handle or an anonymous function with input arguments. Set the BytesAvailableFcn property using this argument.

Example: configureCallback(device,"terminator",@callbackFcn) sets the callbackFcn callback to trigger when a terminator is available to be read.

Data Types: function_handle

Version History

Introduced in R2019b