Define Output Samples in Lowpass Resampler

To demonstrate the variable step discrete behavior of the Lowpass Resampler block, open the model LowpassResamplerOutputSampling.

model = 'LowpassResamplerOutputSampling';
open_system(model)

The model consists of a Pulse Generator and a Lowpass Resampler. The pulse generator generates a pulse of 1 Hz with a duty cycle of 35%. The Pulse type is selected as Time based. In the Lowpass Resampler, the Output rise/fall time is set to 0.05 s, the Number of samples of delay is set to 1, the Output sample time is set to Variable step discrete, and Samples out per rise/fall time is set to 5.

In the Model Settings, the Max step size of the solver is set to 3, the simulation stop time. As a result, the only sample times are those generated by the model and the sample time display is readily understandable.

Run the simulation.

sim(model)

ans = 

  Simulink.SimulationOutput:
                   tout: [97x1 double] 

     SimulationMetadata: [1x1 Simulink.SimulationMetadata] 
           ErrorMessage: [0x0 char] 

To demonstrate the fixed step discrete behavior of the Lowpass Resampler block, set the Output sample time is set to Fixed step discrete. Rerun the simulation and observe the additional samples produced by the model.

set_param([model '/Lowpass Resampler'],'OutputTsType','Fixed step discrete');
sim(model)

ans = 

  Simulink.SimulationOutput:
                   tout: [301x1 double] 

     SimulationMetadata: [1x1 Simulink.SimulationMetadata] 
           ErrorMessage: [0x0 char]