vhe U+4 device helps connect a computer or laptop to a BACnet MSTP network. This helps applications like BACnet clients ( e.g.Cimetrics BACnet Explorer) and diagnostic programs (e.g.Cimetrics BAS-o-matic) access the BACnetMSTP network. The USB port on the U+4 connects to the PC.The U+4 has a microprocessor that handles all the time critical functionality on the MSTP network and passes only the "Time stamped" data to the PC. This helps prevent packet loss. The U+4, once installed, mimics an Ethernet card. The user can choose this newly installed "Ethernet card" for communications with a BACnet MSTP network.