Controlling the Simulink model run status through external API

RTWT workshop is used to generate C code for a Simulink model and start/ stop of the model is controlled through a VC++ GUI (Visula studio 2008) using set_param() commands. This is working fine. But when it is desired to pause the model execution using a similar method (set_param(‘modelname’,’SimulationCommand’,’pause’)), we find that the model does not pause. We have also tried using a assertion block, but of no use. We wanted to know the conditions in which any model cannot be paused (because we have tried the same in a very simple simulink model and it works).

[Kaustubha Govind]

By RTWT, did you mean Real-Time Windows Target, or are you simply using External Mode?

[Kamali]

We use Real time windows target.

Answer 1

[Jan Houska]

Code running in real time generally cannot be paused. That would contradict its purpose to run in real time. For example, if the code controls an externally connected device, pausing the code would get the control algorithm out of sync with the device state. After resuming the paused code the results will be unpredictable.

Please be more specific about what you are trying to achieve by pausing real-time code. Most likely, there are other ways to get the desired effect.

[Kamali]

We are using rtwt generated code to run an aircraft model in a flight simulator.The start/stop of the aircraft is controlled by an instructor station, through engine APIs. Now, we have situations where we have to halt the simulation for some user specific time and restart later from the same position. Pause/ continue is the option. Can u please suggest some solution.

[Jan Houska]

One possibility would be to put the whole model inside an enabled subsystem. Then you can disable the subsystem when the model should be paused and to re-enable it when it should be resumed. This should have an effect very similar to pausing the model.

[Kamali]

Thanks. I could pause/continue the model execution using an enable subsystem. This solves our problem.

[vineetha]

Is it possible to get data from the model while pausing the simulation using subsystem. I have tried retrieving data using enabled subsystem, but it is not working. Is there any way to get data from RTWT while model is running?