Hello everyone,

I have a simulink block diagram that interfaces to a force-feedback haptic device:(http://www.sensable.com/haptic-phantom-omni.htm) in Simulink external mode. I can read position commands from this device and output force-feedback to this device (a block in my diagram does this, and it works fine). I can visualize the position signals on a simulink scope. In addition to that, I want to be able to use these position signals from the device to control a slider in my matlab GUI. 

I included a gain block in the path of the position signal and tried to use  add_exec_event_listener to register an event listener on its output. I understand that the callback registered by add_exec_event_listener is only executed when the corresponding block (in this case the Gain block) in the simulink block diagram is executed. I got errors when I tried to build this, since the diagram is running in external mode.

I found out that since in external mode, blocks are not executed inside simulink, but on the target processor, I cannot simply use add_exec_event_listener to register listeners. So I needed to get this Gain block out from external mode execution. I learnt that by creating an "atomic subsystem"  in my block diagram, I can make some blocks in my block diagram to run inside Simulink rather than in external mode. So I created an "atomic subsystem"  around this Gain block (there are also a few other blocks in this atomic subsystem), and I can now use add_exec_event_listener on the Gain block output. The diagram now builds and even runs without any errors. 

However,  add_exec_event_listener does not really work! The handle to the listener returned by 
h = add_exec_event_listener(blk, event, listener);
is empty (very sad)! 

If I try to edit the handle 'h' in the Matlab workspace by entering my updateGUI() function into it while the block diagram is executing, I can hit breakpoints inside the function. But this is of no use.

If I add a pushButton on my GUI that reads the current Gain block output and updates the GUI slider position (using runtimeObject), it works. But of course, I cannot click on this button at a rate of 500 Hz for a few minutes, which is what I want the listener to do. But it does not do that currently.

Extremely sorry for the long text, I just wanted to be clear enough. Any ideas on how one could solve my problem?

thanks and best regards,
Wetoo

I am running Matlab R2009a on WinXp Pro - Don't know if that has a bearing on whether add_exec_event_listener is correctly operational or not...

"Wetoo " <wetoo.cando@gmail.com> wrote in message <idfhvn$lqd$1@fred.mathworks.com>...
> I am running Matlab R2009a on WinXp Pro - Don't know if that has a bearing on whether add_exec_event_listener is correctly operational or not...

Hi Wetoo,

If you look at the code for add_exec_event_listener you will see that it attaches a handle.listener object to a Simulink.RuntimeObject. Simulink.RuntimeObjects only exist while a simulation is running. To test your model try get_param(gcb, 'RuntimeObject') with your gain block selected both with and without the simulation running. If the get_param returns empty then add_exec_event_listener will also return empty. You will need to write code that starts the simulation and then creates the listener.

Good Luck,

Donn

Thanks very much for your helpful answer Donn!




"Donn Shull" <donn.shull.no_spam@aetoolbox.com> wrote in message <idojen$qm4$1@fred.mathworks.com>...
> "Wetoo " <wetoo.cando@gmail.com> wrote in message <idfhvn$lqd$1@fred.mathworks.com>...
> > I am running Matlab R2009a on WinXp Pro - Don't know if that has a bearing on whether add_exec_event_listener is correctly operational or not...
> 
> Hi Wetoo,
> 
> If you look at the code for add_exec_event_listener you will see that it attaches a handle.listener object to a Simulink.RuntimeObject. Simulink.RuntimeObjects only exist while a simulation is running. To test your model try get_param(gcb, 'RuntimeObject') with your gain block selected both with and without the simulation running. If the get_param returns empty then add_exec_event_listener will also return empty. You will need to write code that starts the simulation and then creates the listener.
> 
> Good Luck,
> 
> Donn

Dear Wetoo,
I have similar problem.
I want to read a sensor's data in External mode of Simulink and show it in a bar graph in GUI. 
As you mentioned, I have used event listeners and every things look good in Normal mode but in External mode my graph does not update. If I run the updategui.m file each time, as you have mentioned, the bar will be updated but this method will not work!!!
I will be grateful if you could help me. I really need to solve this issue as soon as possible.
Thanks in advance for your kind reply.

"Wetoo " <wetoo.cando@gmail.com> wrote in message <ie21jg$89k$1@fred.mathworks.com>...
> Thanks very much for your helpful answer Donn!
> 
> 
> 
> 
> "Donn Shull" <donn.shull.no_spam@aetoolbox.com> wrote in message <idojen$qm4$1@fred.mathworks.com>...
> > "Wetoo " <wetoo.cando@gmail.com> wrote in message <idfhvn$lqd$1@fred.mathworks.com>...
> > > I am running Matlab R2009a on WinXp Pro - Don't know if that has a bearing on whether add_exec_event_listener is correctly operational or not...
> > 
> > Hi Wetoo,
> > 
> > If you look at the code for add_exec_event_listener you will see that it attaches a handle.listener object to a Simulink.RuntimeObject. Simulink.RuntimeObjects only exist while a simulation is running. To test your model try get_param(gcb, 'RuntimeObject') with your gain block selected both with and without the simulation running. If the get_param returns empty then add_exec_event_listener will also return empty. You will need to write code that starts the simulation and then creates the listener.
> > 
> > Good Luck,
> > 
> > Donn