• The U+4 device helps connect a computer or laptop to a BACnet MS/TP network. This helps applications like BACnet clients ( e.g.Cimetrics BACnet Explorer) and diagnostic programs (e.g.Cimetrics BAS-o-matic) access the BACnet/MSTP 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 MS/TP 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 MS/TP network.

    U+4 with Wireshark

    Using the U+4 with the Wireshark, users can capture all communications on the MS/TP network, including token passing. This is critical for troubleshooting. Filter options can be used to capture desired packet types.

  • Power
    The U+4 is powered by a USB port and does not require a separate power supply. Proper power will be indicated by the Power LED indicator is on.

    Data
    The Data LED will indicate any read or write operation within the unit (activity on the network).

    RS485 Connection
    The back panel of the U+4 interface has two connectors. The three conductor screw terminal allows connection of the RS485 network using industrial connectors, and the 9 pin D connector is merely in parallel with these connections, offering an alternative connection.

    MS/TP for RS485 connection - with an appropriate driver
    ANSI/ASHRAE 135 (ISO 16484-5)
    9600, 19200, 28800, 38400, 57600, 76800, 115200 bps data rate
    EIA-485 twisted pair bus physical layer 1200m (abs max) cable length (better rule of thumb: nodes x length in km x speed in kbaud x number of bias, termination flaws should not exceed 30)
    LEDs: activity 
     
    Termination and Bias settings
    Inside the U+4 unit is a header, designated J5, which lets you set termination or bias resistors into the network circuit. When jumpers are in positions 1-2, 3-4, and 5-6 then these resistors are in the
    circuit. NOTE: These are not in the circuit when delivered from the factory.

  • Troubleshoot communications on a BACnet MS/TP LAN

    U+4 Network troubleshootingThe U+4 device helps connect a computer or Laptop to a BACnet/MSTP network. The USB port on the U+4 connects to the PC. The screw terminals help copnnect the BACnet/MSTP network to the U+4 hardware.This helps applications like BACnet clients (such as Cimetrics BACnet Explorer) and diagnostic programs (such as Cimetrics BAS-o-matic) access the BACnet/MSTP network.

    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.

    U+4 with Wireshark

    Using the U+4 with the Wireshark, users can capture all communications on the MSTP network, including token passing. This is critical for troubleshooting. Filter options can be used to capture desired packet types.