What kind of devices are you attempting to inventory?
If you are looking for Windows machines you can open Setup > Assets > Discovery Connections
Choose WHD Discovery Engine (WMI) as your Discovery Tool and WHD will find any Windows machines in the IP Range you specify and add them to Assets in WHD.
If you use JAMF for Macintosh Management, you can have your Assets from JAMF sychronize with WHD automatically. WHD does not currently have a way of synchronizing Mobile Devices from JAMF :-(
If you have a 3rd party service like Absolute Manage (LanRev) or LANSweeper or Microsoft SCCM, you can use those as your Discovery Tool.
Or just import inventory from a spreadsheet and manually maintain…
If you do this one as bvondeylen suggested:
Choose WHD Discovery Engine (WMI) as your Discovery Tool and WHD will find any Windows machines in the IP Range you specify and add them to Assets in WHD
then one of the options when you set that up is to set it to recur on a schedule. As long as the MAC address for your machine(s) will stay the same, it should update the existing record(s) accordingly.
These are PCoIP Zero Clients
We generally name them after the person assigned to the cubicle, but people play a bit of musical chairs as projects start and stop. Being able to rename the device and have it auto-populate would be handy.