DS2401
The DS2401 does nothing really, apart from exisitng on the network and answering with a unique, factory-lasered and tested 64-bit registration number (8-bit family code + 48-bit serial number + 8-bit CRC tester). It is guaranteed that no two parts are alike.The device name is reported back as a DS1990A in my experience. A typical device address is: 01,14,B2,E7,08,00,00,9C.