# Quick start Install and start the Joulescope UI, then connect the JS110 USB port to your computer, as described in [First steps](https://docs.joulescope.com/en/getting_started/first_steps.md#getting-started-first-steps). The JS110 has **IN** and **OUT** ports. Connect the **IN** port to your power source. If using a configurable power supply, set the voltage and current suitable for your device under test. The maximum voltage between **IN+** and **IN-** should never exceed ±15V. **IN** and **OUT** are electrically isolated from USB, but the voltage between any port and USB ground should never exceed ±48V.  Connect the Joulescope **OUT** port to the power input for your device under test.  Operate your device under test. The Joulescope UI starts in the **Multimeter** view, which shows current, voltage, power, charge, and energy. For waveforms over time, select **View** → **Oscilloscope**.