Error when Trying to use Listner Blocks

I am trying to Add a listener to a Scope block in simulink from a GUI. I seem to be adding the listener at the wrong time I think.

The error I am getting is

??? Error using ==> add_exec_event_listener at 94 Can add listener only when block diagram is executing.

Error in ==> guimanualflight>localAddEventListener at 367 eventhandle=add_exec_event_listener('manualflight/xyplot','PostOutputs',@LocalEventListner);

Error in ==> guimanualflight>Start_Callback at 309 set_param('manualflight','StartFcn',localAddEventListener);

This i thought meant that i should add the listener block after starting the simulation. But this also gave me the same result. I am using this guide to listners as a basis :

http://matlabideas.wordpress.com/2011/11/02/guideing-simulink-with-matlab/

The only real difference in the code i am using is that i use the sim command instead of the set_param function to start the model. Does this make a difference?

my code is as follows:

% --- Executes on button press in Start. function Start_Callback(hObject, eventdata, handles) %#ok % hObject handle to Start (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) % set the stop time to inf

 open_system('manualflight.mdl') %opens The Model so control can be taken of it if GUI crashes
 set_param('manualflight','BlockReduction','off')
 figure(guimanualflight) %returns focus to the GUI

 set_param('manualflight/flight_plan/xset', 'Gain', '0') %set initial points as 0.0.0.0
 set_param('manualflight/flight_plan/yawset', 'Gain', '0')
 set_param('manualflight/flight_plan/zset', 'Gain', '0')
 set_param('manualflight/flight_plan/yset', 'Gain', '0');
 set_param('manualflight','StartFcn',localAddEventListener);      

       options=simset('SrcWorkspace','current','DstWorkspace','base') ;
sim('manualflight',[0 Inf],options);

global new_xdata global new_ydata new_xdata=[]; new_ydata=[];

% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % Callback Function for executing the event listener on the scope block % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% function eventhandle=localAddEventListener

eventhandle=add_exec_event_listener('manualflight/xyplot','PostOutputs',@LocalEventListner);

function LocalEventListner(block,eventdata)

global new_xdata global new_ydata

xdata = get(block.OutputPort(1).Data); ydata = get(block.OutputPort(2)); new_xdata=[xdata,new_xdata]; new_ydata=[ydata,new_ydata];

axes(handles.axes1) cla axis ([-1 1 -1 1]) grid on plot(new_xdata,new_ydata)

Answer 1

[Kaustubha Govind]

Try changing:

    set_param('manualflight','StartFcn',localAddEventListener);

To:

    set_param('manualflight','StartFcn','localAddEventListener');

StartFcn needs to be set to a string containing the MATLAB code to be executed. In the first case, the SET_PARAM function is trying to run the function localAddEventListener, with the expectation that it will return a string that must then be set as StartFcn. So the add_exec_event_listener call is made at the time that the set_param command is run, instead of when the model starts executing.

[Paul]

Thanks This worked. The listner was added and if calling my function.

I believe im trying to get the data off the X_Y block incorrectly now.

The error im getting is

??? Error using ==> get_param

Not enough input arguments.

Error in ==> guimanualflight>LocalEventListner at 374

xdata = get_param(block.InputPort(1).Data);

I changed the code so i was trying to get the input data as i relised there are no output ports on a scope.

Am i calling the scope data Incorrectly ?

[Paul]

Im able to solve this problem now. But i am getting a series of error messages.

These are :

??? Error using ==> guimanualflight>Start_Callback at 309

Error due to multiple causes.

Error in ==> gui_mainfcn at 96

feval(varargin{:});

Error in ==> guimanualflight at 42

gui_mainfcn(gui_State, varargin{:});

Error in ==> @(hObject,eventdata)guimanualflight('Start_Callback',hObject,eventdata,guidata(hObject))

Caused by:

Error using ==> guimanualflight>Start_Callback at 309

Error in 'manualflight/2dplot/sfunxy' while executing MATLAB S-function 'sfunxy', flag = 2

(update), at time 0.0.

Error using ==> guimanualflight>Start_Callback at 309

Invalid handle object.

Error using ==> guimanualflight>Start_Callback at 309

Error evaluating 'StopFcn' callback of XY scope. block (mask) 'manualflight/2dplot'. Invalid

handle object.

Error using ==> guimanualflight>Start_Callback at 309

Invalid handle object.

??? Error while evaluating uicontrol Callback

My code for my listner function of plotting the data im having trouble with . Aswhen the model does work which is rare. It wont plot between the limits of the axis i created andwill create new limits. This is the only code i have that seems to have a slight sign of wrking :

function LocalEventListner(block,eventdata) %#ok

global new_xdata

global new_ydata

xdata = (block.InputPort(1).Data);

ydata = (block.InputPort(2).Data);

new_xdata=[xdata,new_xdata];

new_ydata=[ydata,new_ydata];

p=plot(new_xdata,new_ydata);

set(p,'Parent',axes2)

[Kaustubha Govind]

Try running "dbstop if all error" in MATLAB and then run your file. See if it stops in one of your files and examine the variables that the error is complaining about.

Answer 2

[Adrian]

I add a possible solution.

I had the same problem on a subsystem block containing only an input and a terminator block.

I solved using an Atomic Subsystem. Probably Simulink engine was eliminating my simple block because no real calculation were executed