TCP/IP Socket Communications in MATLAB

A simple example TCP/IP server and client

Description

Provides an example Server / Client written in MATLAB that utilises the ability to call Java inline to perform message communication using TCP/IP.

Importantly it does not require any pre-compiled DLLs or force you to compile some MEX c-files. Nor does it require any additional toolboxes Its all contained within the .m files.

To use the example:

- Start 2 instances of MATLAB
- in the first execute the following:
  message = char(mod(1:1000, 255)+1);
  server(message, 3000, 10)
- in the second execute the following:
  data = client('localhost', 3000)

For more details see:
http://iheartmatlab.blogspot.com/2008/08/tcpip-socket-communications-in-matlab.html

• Acknowledgements: This submission has inspired the following:; A simple UDP communications application
• MATLAB release: MATLAB 7.0.4 (R14SP2)
• Other Files: server.m, ; client.m

[Felipe Posada]

Very useful, thank you.

[Jorge Ramírez]

Thanks, it is very easy to use and very useful.

[Maurizio]

It's very useful to build a simple network with MatLab, but in the example you read abyte in a loop. I've tried to read the buffer with the method read (byte [ ] b, int off, int len) of the class DataInputStream, but I don't find anything into the buffer b; the result of this method (the of bytes read) is correct! How can I pass the input buffer to the method?

[Rodney Thomson]

Hi Maurizio,

Unfortunately the read(byte []) method will not work directly from within MATLAB. My thoughts as to why:

When you execute:
  data = zeros(1, 100, 'char');
  data_input_stream.read(data, 0, 100);
It supplies a COPY of the data array which would be populated. Unfortunately you don't have access to this. This requires pass-by-reference semantics which I don't think MATLAB currently support.

To get around this issue personally I've created helper Java classes to read blocks of data and RETURN the Byte array. This requires creating Java classes and compiling them.

Email me if you want some examples.

Rod
  

[Ricardo Correia]

Hello! I have one question.. Can i send wav files through this? Or this is only to send messages?
Thanks for your help