# Multiple Instrument Support The Joulescope UI supports multiple simultaneously connected Joulescope instruments. The UI includes the concept of a **default** device.  The UI will automatically select the initial **default** device. Change the **default** device using the **Device Control** widget. When multiple instruments are connected, the **Waveform** widget displays an additional channel control widget.  Click on the color bar to enable or disable the channel. Right-click on the channel name to select a different device. Click on the channel to select the active channel. The Waveform widget uses the active channel to compute the right-hand side statistics and marker statistics. Changing the active channel will change the statistics computations. The active channel also determines the y-axis labels for the current range signal.