The MATLAB Function block can be used to stream live data into a Simulink model. This can be useful to validate models with real data under different test conditions for example.
This example uses the Data Acquisition Toolbox to process audio data from the Windows soundcard. (It's actually just a modified version of dspstfft_win32.mdl, a demo that ships with the Signal Processing Blockset.)
You could just as easily use the same approach to interface your models to other support plug-in data acquisition hardware, not to mention a variety of other data sources.
* You could interface Simulink to scientific instruments like an oscilloscope, network analyzer, power meter, or waveform generator using the Instrument Control Toolbox.
* Your models could process live video and image data from cameras and frame grabbers supported by the Image Acquisition Toolbox.
* You could hook your model up to Oracle or another ODBC or JDBC compliant database using the Database Toolbox.
* Your Simulink models can take advantage of MATLAB's Generic DLL calling capability.
Just about anything you can do in MATLAB, you can use the MATLAB Function block to do from Simulink.
Hopefully this example helps get you started. For more advanced capabilities, refer to the Simulink documentation regarding S-functions, particularly M-file S-functions. They are more sophisticated and use a particular API which provides a lot of power and functionality.
Happy modeling and simulating with live data!