Transition Your Code to udpport Interface

The udp function, its object functions, and its properties will be removed. Use udpport instead.

udp Interfaceudpport InterfaceExample
udp, DatagramTerminateMode, and fopenudpportConnect to UDP Socket
instrfind and instrfindalludpportfindFind Existing UDP Socket Connections
fwritewriteRead and Write
freadread
fprintfwritelineRead Terminated String
Write and Read Back Data
fscanfreadlineRead Terminated String
fgetlRead and Parse String Data
fgetsWrite and Read Back Data
flushinput and flushoutputflushFlush Data from Memory
TerminatorconfigureTerminatorSet Terminator
BytesAvailableFcnCount, BytesAvailableFcnMode, and BytesAvailableFcnconfigureCallbackSet Up Callback Function
DatagramReceivedFcn
BytesAvailableNumBytesAvailable 
OutputDatagramPacketSizeOutputDatagramSize 
ErrorFcnErrorOccurredFcn 
fcloseclear and deleteDisconnect UDP Socket

Removed Functionality

The binblockread and binblockwrite functions will be removed.

The DatagramAddress and DatagramPort properties are the SenderAddress and SenderPort properties of the Datagram structure returned by the read function in the updated interface.

The RemoteHost and RemotePort properties are input arguments for the write and writeline functions in the updated interface. The LocalPortMode property is part of the LocalPort property in the updated interface.

The ValuesReceived and ValuesSent properties will be removed. You can calculate the number of values sent using the NumBytesAvailable property and the data type of the data available. For example, if the NumBytesAvailable is 20 bytes of uint32 data, the number of values sent is five since each uint32 value is four bytes.

The readasync and stopasync functions and the ReadAsyncMode and TransferStatus properties will be removed. The updated interface reads data asynchronously.

The BytesToOutput, InputBufferSize, OutputBufferSize, and InputDatagramPacketSize properties will be removed. Buffer sizes and received datagram sizes are automatically managed and sized as needed.

The OutputEmptyFcn property will be removed. You can set callback functions using configureCallback in the updated interface, but not for this property.

The RecordDetail, RecordMode, RecordName, and RecordStatus properties will be removed.

The TimerFcn and TimerPeriod properties will be removed. Use timer instead.

The Name, Type, ObjectVisibility, Status, and Tag properties will be removed.

Connect to UDP Socket

These examples show how to connect to a UDP socket using the recommended functionality.

FunctionalityUse This Instead
u = udp;
u.DatagramTerminateMode = "off";
fopen(u)
 
uByte = udpport("byte");
u = udp;
u.DatagramTerminateMode = "on";
fopen(u)
 
uDatagram = udpport("datagram");

The fopen function is not available in the updated interface. The object creation function udpport both creates and connects the object.

For more information, see udpport.

Find Existing UDP Socket Connections

instrfind and instrfindall will be removed. Use udpportfind instead. (since R2024a)

Read and Write

These examples use an echo server to show how to perform a binary write and read, and write and read a nonterminated string using the recommended functionality.

FunctionalityUse This Instead
echoudp("on",9090)

% u is a udp object
u.DatagramTerminateMode = "off";
fwrite(u,1:5);
data = fread(u,5)
data =

     1
     2
     3
     4
     5
 
echoudp("on",9090)

% uByte is a udpport byte object
write(uByte,1:5,"127.0.0.1",9090)
data = read(uByte,5)
data =

     1     2     3     4     5

echoudp("on",9090)

% u is a udp object
u.DatagramTerminateMode = "on";
fwrite(u,1:5);
data = fread(u,1)
data =

     1
     2
     3
     4
     5
 
echoudp("on",9090)

% uDatagram is a udpport datagram object
write(uDatagram,1:5)
data = read(uDatagram,1)
data = 

  Datagram with properties:

             Data: [1 2 3 4 5]
    SenderAddress: "127.0.0.1"
       SenderPort: 9090
echoudp("on",9090)

% u is a udp object
fwrite(u,"hello","char")
length = 1;
data = fread(u,length,"char")
data =

   104
   101
   108
   108
   111
data = char(data)'
data =

    'hello'
 
echoudp("on",9090)

% uByte is a udpport byte object
write(uByte,"hello","string","localhost",9090);
length = 5;
data = read(uByte,length,"string")
data =

    "hello"
echoudp("on",9090)

% uDatagram is a udpport datagram object
write(uDatagram,"hello","string","localhost",9090);
length = 1;
data = read(uDatagram,length,"string")
data = 

  Datagram with properties:

             Data: "hello"
    SenderAddress: "127.0.0.1"
       SenderPort: 9090

For more information, see write or read.

Read Terminated String

This example shows how to perform a terminated string write and read using the recommended functionality.

FunctionalityUse This Instead
echoudp("on",9090)

% u is a udp object
u.Terminator = "CR";
fprintf(u,"hello")
data = fscanf(u)
data =

    'hello
     '
 
echoudp("on",9090)

% uByte is a udpport byte object
configureTerminator(uByte,"CR");
writeline(uByte,"hello","127.0.0.1",9090);
data = readline(uByte)
a = 

    "hello"
echoudp("on",9090)

% u is a udp object
u.Terminator = "CR";
fprintf(u,"hello")
data = fgetl(u)
data =

    'hello'

fgetl reads until the specified terminator is reached and then discards the terminator.

echoudp("on",9090)

% u is a udp object
u.Terminator = "CR";
fprintf(u,"hello")
data = fgets(u)
data =

    'hello
     '

fgets reads until the specified terminator is reached and then returns the terminator.

For more information, see writeline or readline.

Read and Parse String Data

This example shows how to read and parse string data using the recommended functionality.

FunctionalityUse This Instead
% u is a udp object
data = scanstr(u,';')
data =

  3×1 cell array

    {'a'}
    {'b'}
    {'c'}
 
% uByte is a udpport byte object
data = readline(uByte)
data = 

    "a;b;c"
data = strsplit(data,";")
data = 

  1×3 string array

    "a"    "b"    "c"

For more information, see readline.

Write and Read Back Data

This example shows how to write ASCII terminated data and read ASCII terminated data back using the recommended functionality.

FunctionalityUse This Instead
% u is a udp object
data = query(u,'ctrlcmd')
data =

    'success'
 
% uByte is a udpport byte object
writeline(uByte,"ctrlcmd")
data = readline(uByte)
data = 

    "success"

For more information, see writeline or readline.

Flush Data from Memory

This example shows how to flush data from the buffer using the recommended functionality.

FunctionalityUse This Instead
% u is a udp object
flushinput(u)

% u is a udpport byte or datagram object
flush(u,"input")
% u is a udp object
flushoutput(u)

% u is a udpport byte or datagram object
flush(u,"output")
% u is a udp object
flushinput(u)
flushoutput(u)

% u is a udpport byte or datagram object
flush(u)

For more information, see flush.

Set Terminator

These examples show how to set the terminator using the recommended functionality.

FunctionalityUse This Instead
% u is a udp object
u.Terminator = "CR/LF";
 
% u is a udpport byte or datagram object
configureTerminator(u,"CR/LF")
% u is a udp object
u.Terminator = {"CR/LF" [10]};
 
% u is a udpport byte or datagram object
configureTerminator(u,"CR/LF",10)

For more information, see configureTerminator.

Set Up Callback Function

These examples show how to set up a callback function using the recommended functionality.

FunctionalityUse This Instead
% u is a udp object
u.BytesAvailableFcnCount = 5;
u.BytesAvailableFcnMode = "byte";
u.BytesAvailableFcn = @mycallback;

function mycallback(src,evt)
   data = fread(src,src.BytesAvailableFcnCount);
   disp(evt)
   disp(evt.Data)
end

    Type: 'BytesAvailable'
    Data: [1×1 struct]

    AbsTime: [2019 12 21 16 35 9.7032]
 
% uByte is a udpport byte object
configureCallback(uByte,"byte",5,@mycallback);

function mycallback(src,evt)
   data = read(src,src.BytesAvailableFcnCount);
   disp(evt)
end
  ByteAvailableInfo with properties:

    BytesAvailableFcnCount: 5
                   AbsTime: 21-Dec-2019 12:23:01
% u is a udp object
u.DatagramTerminateMode = "on";
u.DatagramReceivedFcn = @mycallback;

function mycallback(src,evt)
   data = fread(src,src.BytesAvailableFcnCount);
   disp(evt)
   disp(evt.Data)
end

    Type: 'DatagramReceived'
    Data: [1×1 struct]

            AbsTime: [2019 12 21 16 35 9.7032]
    DatagramAddress: '127.0.0.1'
       DatagramPort: 9090
     DatagramLength: 1

% uDatagram is a udpport datagram object
configureCallback(uDatagram,"datagram",1,@mycallback);

function mycallback(src,evt)
   data = read(src,src.DatagramsAvailableFcnCount);
   disp(evt)
end
  DatagramAvailableInfo with properties:

    DatagramsAvailableFcnCount: 1
                       AbsTime: 21-Dec-2019 12:23:01
% u is a udp object
u.Terminator = "CR";
u.BytesAvailableFcnMode = "terminator";
u.BytesAvailableFcn = @mycallback;

function mycallback(src,evt)
   data = fscanf(src);
   disp(evt)
   disp(evt.Data)
end

    Type: 'BytesAvailable'
    Data: [1×1 struct]

    AbsTime: [2019 12 21 16 35 9.7032]
 
% uByte is a udpport byte object
configureCallback(uByte,"terminator",@mycallback);

function mycallback(src,evt)
   data = readline(src);
   disp(evt)
end
  TerminatorAvailableInfo with properties:

                   AbsTime: 21-Dec-2019 12:23:01

For more information, see configureCallback.

Disconnect UDP Socket

The fclose function is not available in the updated interface. To disconnect a UDP socket, use clear or delete instead, depending upon whether you are working in a single workspace or multiple workspaces. For details, see the following examples on the udpport reference page:

See Also