GUI to controll of SMULINK simulation - start/stop problems

Hello,

I've been making a GUI in GUIDE to controll my Simulink mode, which controls an inverter using external mode. Since the purpose is to make a kind of a demo with it, I wanted to control the Simulink model through a GUI. In the GUI there are several text boxes to set parameters and a start and a stop button. And here is the problem: when I press "start" or "stop", the model always goes into "pause". Because I run in external mode, it is necessary to connect to the target first. When I connect with the target by pressing the connect-button in simulink and then press "start" in the GUI, the model's simulation status goes into "Pause". When I try to connect with the target by pressing the "start" button there is an error showing up:

-code for the start button:

function start_Callback(hObject, eventdata, handles)

set(get(handles.control,'Children'),'Enable','off');    %to disable some options once started                   
*status = get_param(CL_Buck_PI_hardware,'Simulationstatus');*    %line 110             

if ~strcmp(status,'running')                    %check if the model is 

already running    
    set_param(CL_Buck_PI_hardware,'Simulationcommand','connect') %connect with target (ext mod)
    set_param(CL_Buck_PI_hardware,'simulationcommand','start')   %start the simulink model
  end
    % Assign handles and the startstop object to the base workspace 
assignin('base','Buckconverter_handles',handles)
assignin('base','start_hObject',handles.start)

-error message:

Error using Buckconverter>start_Callback (line 110) %line 110 is market in bold in the code

Invalid Simulink object handle

Error in gui_mainfcn (line 96) feval(varargin{:});_

Error in Buckconverter (line 42) gui_mainfcn(gui_State, varargin{:});

Error in @(hObject,eventdata)Buckconverter('start_Callback',hObject,eventdata,guidata(hObject))

Error while evaluating uicontrol Callback _

Weird thing is that I can see the model starts to initiate but all of a sudden it stops and I get this error message.

The same kind of error appears when I start the simulation myself in the simulink window and then press the "stop"-button.

   set(get(handles.control,'Children'),'Enable','on');%enable changes in GUI when "stop" = pressed
  *status = get_param(CL_Buck_PI_hardware,'simulationstatus');*            %Model running?

if strcmp(status, 'running')             %if so, stop the model
    set_param(CL_Buck_PI_hardware,'simulationcommand','stop')
end

% Assign handles and the startstop object to the base workspace 
assignin('base','Buckconverter_handles',handles

The error message is the same as with the start button, and is marked in bold. I don't know what I'm doing wrong, because I thought I just follwed the set_param() instruction like showed in using real time applications

Who sees what I'm doing wrong?

Thanks in advance!

FYI: 'Buckconverter' is the name of my GUI and 'CL_Buck_PI_hardware' is the name of my simulink model

[Kaustubha Govind]

When you say:

   set_param(CL_Buck_PI_hardware,'simulationcommand','stop')

You're implying that CL_Buck_PI_hardware is a variable that holds the name of your model. Does such a variable exist in the function workspace? If not, you need to use single-quotes around it to indicate that the model name itself is CL_Buck_PI_hardware.

   set_param('CL_Buck_PI_hardware','simulationcommand','stop')

[Jannick]

OK, thank you very much for correcting my rookie mistake. 2 problems down, I hope not that many more to go!