This example shows how to use a Bus Assignment block to change a bus element value without adding Bus Selector and Bus Creator blocks to select bus elements and reassemble them into a bus.
Open the model and simulate it.
ans = Simulink.SimulationOutput: tout: [51x1 double] SimulationMetadata: [1x1 Simulink.SimulationMetadata] ErrorMessage: [0x0 char]
Initially, the value of signal a is 1. However, the Bus Assignment block replaces that initial value of signal a with the value of signal c, which is 3. The const_bus output signal has a value of 3 for signal a, as the Display block shows.