MATLAB: Does set_param(‘the_model’, ‘SimulationCommand’, ‘continue’, ‘SimulationCommand’, ‘pause’) within a loop work in R2016b, but not in R2016a

simulink

The following command within a loop works well in R2016b:

>> set_param('my_model', 'SimulationCommand', 'continue', 'SimulationCommand', 'pause')

However, in R2016a, the model simulation has no response when running that command.

Best Answer

This syntax is not documented and is thus not recommended. Please see here for example uses:

https://www.mathworks.com/help/simulink/ug/using-the-sim-command.html#mw_13764672-77b5-469a-8b1e-d2c587c500f4

Related Solutions

MATLAB: Do I receive an “Undefined function or variable” for “simout” inside an Assertion block callback in Simulink 8.5 (R2015a)

The error message is due to the following missing callback

set_param(bdroot,'SimulationCommand','WriteDataLogs')

Here is what happens without the missing callback to WriteDataLogs:

- The assertion block runs with non-zero input, and executes the callback

- The command "set_param(bdroot,'SimulationCommand','pause')" sets the parameter.

- The command "disp('Simulation paused.')" prints to the command window.

- The command "evalin('base','plot(simout.signals.values)')" fails because simout is not yet in the base workspace.

- The solver sees that parameter SimulationCommand' is 'pause', so it does not start another time step.

Adding the missing callback makes the 'To workspace' block write its data to the workspace immediately, so it is available when the plot command executes.

There is one additional issue with the code supplied in the question: you cannot pause and resume simulation within an Assertion block callback. As mentioned in the documentation, setting "SimulationCommand" to "pause" or "continue" makes a request to the solver - it does not cause immediate action. In this case, the solver will not process that request until after the callback finishes. Thus, throughout the execution of the callback, the "SimulationStatus" is "running." The call to "set_param" that is supposed to set "SimulationCommand" to "continue" will be ignored, and when the callback exits the simulation will pause. Because the execution of the callback happens within one solver step, pausing and resuming is unnecessary here. The correct callback code would be:

set_param(bdroot,'SimulationCommand','WriteDataLogs')    
evalin('base','plot(simout.signals.values)'); 
disp('Data plotted.');

MATLAB: I am using the test manager to run the tests in a model. In the Test Sequence editor I make a call to the following code as the last step. coder.extrinsic(‘bdroot’); coder.extrinsic(‘set_param’); set_param(bdroot, ‘SimulationCommand’, ‘stop’);

You must have an output of the Test Sequence block to a Stop Simulation block and have the Test Sequence block change the output to true when you want the simulation to stop.

Here are some steps:

1. Initialize a output variable to false in the Test Sequence block

2. In your proposed step in the Test Sequence block, change this output variable to true.

3. Connect this output to the Stop Simulation block, so that the Simulation is stopped by the Stop Simulation block.

Best Answer

Related Solutions

MATLAB: Do I receive an “Undefined function or variable” for “simout” inside an Assertion block callback in Simulink 8.5 (R2015a)

MATLAB: I am using the test manager to run the tests in a model. In the Test Sequence editor I make a call to the following code as the last step. coder.extr​insic(‘bdr​oot’); coder.extr​insic(‘set​_param’); set_param(bdroot, ‘SimulationCommand’, ‘stop’);

Related Question

MATLAB: I am using the test manager to run the tests in a model. In the Test Sequence editor I make a call to the following code as the last step. coder.extrinsic(‘bdroot’); coder.extrinsic(‘set_param’); set_param(bdroot, ‘SimulationCommand’, ‘stop’);