There are two methods to check the status of connected devices:

• Remotely using the Google Admin panel
• Locally on the Chromebox

Google Admin Panel (admin.google.com)
Connected USB devices can be quickly checked by logging into the Google Admin panel and selecting the designated room in the Device Management panel.

Locally on the Chromebox
Click the settings cog in the lower right-hand corner of the screen and check the devices located under the Audio, Video and Display tabs.