Devices associates the physical devices with the object you are creating. Devices will always have at a minimum an Interface specified as the first value. Devices, like Addresses, are one of the few attributes that don't have any rules or other values associated with them. They are a link to a physical object.
Assign the object as an UPB device and connect it to a contact on a door that emits an OPEN / CLOSED signal and a motion detector that emits a MOTION / STILL signal.