Using a websocket connection in Matlab

Hi

I'm trying to connect via the LAN to a piece of software which can receive commands via a HTML5 websocket connection. Is there any straight forward way to send commands to a websocket command line using Matlab?

UPDATE:

I've found WeSocket4Net which seems like it should do what I need to: http://websocket4net.codeplex.com/documentation

... but struggling to use it. I've added the assembly like this: asm = NET.addAssembly('c:\Reference\WebSocket4Net.dll');

But when I try to create an instance of the WebSocket Class I get an error:

webSockInstance = WebSocket4Net.WebSocket Error using WebSocket4Net.WebSocket No constructor 'WebSocket4Net.WebSocket' with matching signature found.

Adam

Answer 1

[Jeremy]

Check out MatlabWebSocket .

Disclaimer: I am the author.

Answer 2

[Luca Malgo]

Hi All! I found a nice workarround to comunicate with a websocket from MatLab! Python (i'm currently using the version 3.6) can comunicate easily with websockets due to the the websocket-client package (pip3 install websocket-client). As much as easily python can stand a websocket, Matlab can call python functions!

Here a bit of exemplary code:

1) Create a function.py file with the function for the websocket comunication

import websocket as ws_lib
def Connection_send_Recieve(WebSocket_Ip,Port,Command):
   Str="ws://"+WebSocket_Ip+":"+Port
   ws = ws_lib.create_connection(Str)
   ws.send(Command)
   RecivedData=ws.recv_data()
   ws.close()
   return RecivedData

You have to save the python file in your working folder, and than you can call the function from matlab, as in the following exemplary code:

Ws_Ip='192.168.0.1';
Port='1234';
Command='CommendFormattedAsYourWebSocketWantToReciveIt'
Result=py.function.Connection_send_Recieve(Ws_Ip,Port,Command);

Now you have an output in python string format. To work with standard matlab string you should convert the result with one of the following commands

Results=string(Results);
Results=char(Results);

For further information you should look at the matlab reference for caling python function Python and Matlab and the python websocket-client references Python Websocket

Good coding to all! Luca M.

[Rik]

Comment posted as flag:

I solve the problem using just the matlab code and a simple python library. Easier and cross-platform compatible (other solution are not especially in the 2018 matlab versions)

[Rajeswar Reddy G CB.EN.P2AEL16018]

Hi Luca,

I am trying to achieve same functionality.

But when i run the function, i am getting an error.

>> Ws_Ip='192.168.0.1';

Port='1234';

Command='CommendFormattedAsYourWebSocketWantToReciveIt'

Result=py.function.Connection_send_Recieve(Ws_Ip,Port,Command);

Command =

'CommendFormattedAsYourWebSocketWantToReciveIt'

Undefined variable "py" or class "py.function.Connection_send_Recieve".

One more question. I have to use sockets with simulink. Also need to support code generation. Will this method work even with code generation. I use simulink coder or embedded coder or rtwbuild for code generation.