Tcpserver and callbacks. How to pass variables?

Hello everyone,

i'm using the tcpserver function

t = tcpserver('127.0.0.1', 1234,"ConnectionChangedFcn",@connectionFcn)

So when a connection is estabilished the function connectionFcn is executed and it does some code.

I want to know if it is possible to pass some variables to this connectionFcn

For example i would like to pass this function an array, and within the connectionFcn stores some data that will be accessible for later computations.

Answer 1

[Sharad]

Hi,

As per my understanding, you are interested in knowing whether some variable can be passed to the connectionFcn while using tcpserver function.

It is possible to pass variables in the connectionFcn, and can be done in the following manner.

• Declare and define the variable that you want to pass.

data = [1 2 3 4 5];

• Call the tcpserver function in the following manner with parameters to connectionFcn.

t = tcpserver('127.0.0.1', 5678, "ConnectionChangedFcn", @(conn) connectionFcn(conn, myData));

• Define the connectionFcn function.

function connectionFcn(conn, data)
    % Your code here
    % Use the 'data' variable as needed
    disp(data);
end

Here are some documentation links that you might want to follow:

tcpserver : https://in.mathworks.com/help/instrument/tcpserver.html

anonymous functions : https://in.mathworks.com/help/matlab/matlab_prog/anonymous-functions.html

Thank you.

[Giovanni Di Girolamo]

Thanks very much. I was looking at the anonymnous function and your example cleared my mind.

[Ricardo Kehrle Miranda]

I tryied your example and I get

Too many input arguments.

Error in tcpserver.internal.TCPServerCustomClient/connectionCallbackFunction

Any ideas?