how to generate simulink signal (data value with specific time time )

i success to pull on a file inside Simulink and read a signal value but i don't know how to block or generate this value signal at specific time

    function y=fcn()
    fprintf('XD\n');
    fifo_in = 'C:\Users\kkhalil\Desktop\matlab.ipc-master\matlab.ipc-master\fifo1.txt';
    fin = fopen(fifo_in, 'r');
    fprintf('reading...\n');
    nData =  fread(fin, 1, 'uint8=>char') ;
    data = uint8(nData)-48 ;
     fclose(fin);
     y =  uint8(data);

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