Run Slave Simulation. Press Run Slave Simulation on the tool bar, or type Ctrl-R, or use Settings → Run Slave Simulation to start the slave simulation. (The button is not enabled if there are no slaves and no environment properties). When the simulation starts, the changing slave register values are displayed in the Slave Registers display area of the main window at the configured Run Interval. Likewise, changing environment values are displayed in the Environment Properties display area.