Problem with MATLAB function

Hello, everyone!

I'm trying to do the "real-time" computation with Simulink. For this I try the MATLAB Function with the system on pic. The subsystem Sys1 consits of two aperiodic links. The MATLAB should compute the optimal control for this system.

But I meet some problems with this.

The first one and most hard is that I can't find the way to programmatically stop or start some of the code execution in MATLAB function. In my case, I need to do some computations with Inputs of MATLAB function only when Output of the Sys1 x1 is smaller than 0.8 or greater then 1.2.

For simplification of the poblem I do not provide a calculating part of the code, but only the answers it would give.

Inside MATALB Function I have the following code:

function Control  = fcn(Clock,x1,x2,A1,B1,A2,B2)
%Duration of control intervals to "Start" the system
TIME0=[0.416398568470955,0.306200290286777];
%4 is taken because of the external influence is
%attached on 4 sec
if Clock<=4
    BEB=0;
else
    BEB=1;
    %Duration of control intervals to return the system to nominal output
    TIME0=[0.3506 0.1779];
end
if BEB==1
    if 4<=Clock&&Clock<=TIME0(1)+4
    Control=5;
    elseif Clock>=TIME0(1)+4&&Clock<=sum(TIME0)+4
    Control=0;
    else
    Control=2.298498;%Normal rate of control that gives the nominal output
    end
else
    if Clock<=1
        Control=0;
    else
        if 1<=Clock&&Clock<=TIME0(1)+1
        Control=5;
        elseif Clock>=TIME0(1)+1&&Clock<=sum(TIME0)+1
        Control=0;
        else
        Control=1.53233220962305;%Normal rate of control that gives the nominal output
        end
    end
end

This code is horrible, so I want to make something that will automatically.

If anyone will need the system parametrs - that they are: A1=-2.0408; B1=1.3318; A2=-2.0833; B2=2.0833

Thanks in advance!