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UDP Send

Send UDP message




  • UDP Send block


The UDP Send block transmits an input vector as a UDP message over an IP network port. The remote IP port number to which the block sends the UDP packets is tunable in the C/C++ generated code.


Some Simulink® blocks and .exe files built from models that contain those blocks require shared libraries, such as .dll files on Windows®. The UDP Send block requires the networkdevice.dll library file. To meet this requirement, follow the example on the packNGo (Simulink Coder) function page to package the code files for your model. The resulting compressed folder contains the .dll files that the model requires, including networkdevice.dll. To run this type of .exe file outside a MATLAB® environment, place the required .dll files in the same folder as the .exe file, or place them in a folder on the Windows system path. For more details, see How To Run a Generated Executable Outside MATLAB.


Remote IP address ('' for broadcast)

Specify the IP address or hostname to which the block sends the message. To broadcast the UDP message, retain the default value, ''.

Remote IP port

Specify the port to which the block sends the message. This parameter is tunable in the C/C++ generated code but not tunable during simulation. The default is 25000. The value can be in the range [1, 65535].


On Linux®, to set the IP port number below 1024, run MATLAB with root privileges. For example, at the Linux command line, enter:

sudo matlab

Local IP port source

To let the system automatically assign the port number, select Automatically determine. To specify the IP port number using the Local IP port parameter, select Specify via dialog.

Local IP port

Specify the IP port number from which the block sends the message.

If the receiving address expects messages from a particular port number, enter that number here.

Send buffer size (bytes)

Size of the internal buffer that sends UDP packets, specified in bytes as a scalar in the range [1, 67108864]. By default, the parameter is set to 8192 bytes.

Extended Capabilities

Introduced in R2010a