Matlab Serial Communication XBEE with LINUX - ttyUSB0 failure

Projects Interfacing w/ Software on the Computer
2

this code is working with windows 7 and matlab.

%


instrhwinfo('serial');
ports = ans.AvailableSerialPorts

pause(1);
clc

display(['Scanning...']);

s1 = serial('COM4');    % define serial port ACM0 / USB0
s1.BaudRate=9600;               % define baud rate
set(s1, 'terminator', 'LF');    % define the terminator for println CR or LF
fopen(s1);




try                             % use try catch to ensure fclose
                                % signal the arduino to start collection
w=fscanf(s1,'%s')              % must define the input % d or %s, etc.
if (w=='A')
    display(['Collecting data']);
    fprintf(s1,'%s\n','A');     % establishContact just wants something to buffer
end




fclose(s1);
             
catch exception
    fclose(s1);
    delete(s1);
    clear s1;
    %freeserial;
end

so it seems the only problem are the usb ports. i have to define the right port to receive the data in matlab.