The sldemo_fuelsys model uses a Multiport Switch block in the fuel_rate_control/fuel_calc/feedforward_fuel_rate subsystem. This block uses the enumerated type sld_FuelModes to specify three data port indices: LOW, RICH, and DISABLED.

When you set Data port for default case to Last data port, the last data port includes a * on the label. The comma and ellipsis after the * indicate that the data port index has a value. This port corresponds to the default case, which applies when the control input does not match the data port indices LOW, RICH, or DISABLED. In this case, the Multiport Switch block outputs a value of 0.