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Model Variable Propagation Delay

Open the model VariablePropagationDelay. The model uses the Propagation Delay block to delay the output from a Sine Wave block. The delay signal is modeled using a Step block.

The Sine Wave and Delay signals are logged using signal logging. The Delayed Sine Wave signal is logged using output logging.

mdl = "VariablePropagationDelay";

Simulate the model. Then, open the Simulation Data Inspector and use the Simulink.sdi.loadView function to load the view VariablePropDelayView.mldatx.

out = sim(mdl);

The delay signal value must be greater than zero throughout the simulation, so the Step block is configured to step from an initial value of 0.2 to a value of 1 at a simulation time of 2 seconds.

For the first simulation step, at 0 seconds, the Delayed Sine Wave signal value is the Initial output value defined for the Propagation Delay block, 0.1.

On the next time step, the delay of 0.2 seconds has elapsed, and the Propagation Delay block output is determined by the delayed sample values.

When the simulation reaches 2 seconds, the step occurs, and the delay becomes 1 second instead of 0.2 seconds. The Propagation Delay block holds the output value for the 1 second delay. Then, the output updates to the sample taken when the step occured. For the rest of the simulation, the delay between the input and output is 1 second, and the Propagation Delay block output is determined by input signal samples.

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