how to disconnect tcp/ip connection?

I made tcp/ip server and client like this

server = tcpserver('0.0.0.0',111);

and another app

cli = tcpclient('localhost',111);

It is perfectly connected.

So, how to disconnect TCP/IP form client?

and how to disconnect from server?

Answer 1

[Harikrishnan Balachandran Nair]

Hi,

You can close the TCP/IP connection by clearing the 'tcpclient' object using the 'clear' function .

Please refer to the following documentations to get a better idea on this :

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

https://www.mathworks.com/help/matlab/ref/tcpclient.html

Hope this helps!

[Jae-Hee Park]

I tried but does not work.TT

It still connected.

[chuck shen]

I used “clear” to disconnect the TCP/IP link in .m code, and it seems work well. But in the MATLAB APP designer, "clear" command could not work.

clc;clear;close all;

t_client = tcpclient('192.168.137.100',5551,"Timeout",5);
data_send=input('Please input the word you want to send. \n','s');
% only supported by 2021b or later
write(t_client,data_send,"string");
% t_client.NumBytesAvailable could not be updated immediately
pause(0.1)  
data_recv = read(t_client,t_client.NumBytesAvailable,"string")
clear t_client

  % Button pushed function: StartButton
        function StartButtonPushed(app, event)
            app.t_client = tcpclient('192.168.137.100',5551,"Timeout",5);
        end

        % Button pushed function: PauseButton
        function PauseButtonPushed(app, event)
            data_send='hello';
            write(app.t_client,data_send,"string");
            pause(0.1);  
            data_recv = read(app.t_client,app.t_client.NumBytesAvailable,"string");
            fprintf('%s\n',data_recv);
        end

        % Button pushed function: StopButton
        function StopButtonPushed(app, event)
            clear app.t_client;
        end

[chuck shen]

Use

delete(app.t_client);

instead in MATLAB APP designer.

https://ww2.mathworks.cn/matlabcentral/answers/449835-app-designer-how-do-i-clear-all-variables

[Jae-Hee Park]

@chuck shen Thank you.

delete(app.client);

Above command works clear the values of app.client but do not erase the app.client.

%ex) 
delete(app.client);
isa(app.client,'tcpclient'); % is true

There is no way to completely erase the app.client?

[Eric Delgado]

@Jae-Hee Park

I was dealing with the same issue, using appDesigner and create a handle (property of my app) to a tcpclient object. The new solution was the "old solution" (used in "tcpip" objects).

delete(app.client)
clear app.client

The validation isa(app.client,'tcpclient') as true is not a problem at all. You can create other tcpclient object and handling this object in "app.client".