U+4 USB to BACnet MS/TP Interface

B2110


Collections: BACnet

Category: B2110, BACnet, MS/TP, RS-485

Type: BACnet


  • 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 BAS-o-matic

    Using the U+4 with the BAS-o-matic, 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.

    U+4 with BACnet Explorer

    Using the U+4 with BACnet Explorer, users can discover all BACnet devices on an MS/TP network. Once the devices are discovered, their objects and property information can be automatically populated. Users can also exercise the Read Property and Write Property services on the supported objects.


  • Power

    The U+4 is powered by the USB port and does not require a separate power supply. Proper power will be indicated by the Power LED indicator being 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 BAS-o-matic

    Using the U+4 with the BAS-o-matic, 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.

Product Q&A

Ask a Question
0
Q: How do I use the U+4 with a BACnet client?

A: The U+4 hardware is an intelligent USB to fieldbus interface. This allows you to use your PC's USB port to connect to an MSTP (RS485) network. The U+4 (along with a BACnet client like the Cimetrics BACnet Explorer) can now communicate with a BACnet/MSTP network to write and read values.

The following needs to be done for a connection;

- In your LAN properties, select your NIC interface and get into Properties | uncheck the Cimetrics BACstac protocol

- Install the driver for the U+4 on your PC

- Plug the device into your PC (In the USB port).Once the U+4 is plugged into the PC in the USB slot, this will add an extra Local Area Connection in your Network Places that corresponds to the U+4. In order to configure settings, you would need to select this Local Area Connection.

Once you are in the Local Area Connection, RT Click | Properties |Configure | Advanced, you will see all the options given below. Please configure according to your use.


Card Speed:

Select needed Baud rate(in the range from 1200 to 115200 bps) from the list

Filter:

-"Directed BACnet NPDU only" - to receive only directed or Broadcast NPDU. (accepted by any BACstac version). MS/TP information is absent.

Node Address:

Set address of this node in the range [0-254]. IMPORTANT Note: Master node must be in the range [0-Max_master]

Node Type:

Select "Master Node".

Master Mode takes part in token passing and is needed for the BACstac. In this mode, you would be able to completely discover the MS/TP network by using the BACnet Explorer.


Max_info_frames[1-10]:

Leave at default settings.

Max_master[1-127]:

Leave this at the default settings.


Once the above settings are done, you should be able to start the BACnet Explorer and discover devices from a BACnet/MSTP network.

1
Q: How does the U+4 Field interface get its power?

A: The U+4 Device draws its power from the USB cable and hence will not require any other power source.

2
Q: How do I use the U+4 with the BAS-o-Matic to sniff a network?

A: The U+4 hardware is an intelligent USB to fieldbus interface. This allows you to use your PC's USB port to connect to an MSTP (RS485) network for sniffing the MSTP Network. This sniffing can be done with the help of the Cimetrics Sniffing software called as the BAS-o-Matic.

The following needs to be done for a connection;

  • Install the driver for the U+4 on your PC
  • Plug the device into your PC (In the USB port).Once the U+4 is plugged into the PC in the USB slot, this will add an extra Local Area Connection in your Network Places that corresponds to the U+4. In order to configure settings, you would need to select this Local Area Connection.
Once you are in the Local Area Connection, RT Click | Properties |Configure | Advanced, you will see all the options given below. Please configure according to your use.

Card Speed:

Select needed Baud rate(in the range from 1200 to 115200 bps) from the list

Filter:

Use the filter option to select what kind of packets you want to capture or receive:
  • "All" - to receive all packets (including all types of MS/TP frames and error notifications)
  • "All BACnet data" - to receive all MS/TP frames transporting BACnet NPDU.
  • "Directed BACnet data" - to receive MS/TP frames with BACnet NPDU, destined only to our Node Address and Broadcasts.
  • "Directed BACnet NPDU only" - to receive only directed or Broadcast NPDU. (accepted by any BACstac version). MS/TP information is absent.
Node Address:

Set address of this node in the range [0-254]. IMPORTANT Note: Master node must be in the range [0-Max_master]

Node Type:

Select "Monitor Node". The "Monitor" mode can be used for Bas-o-matic only. This mode would be used if you are using the fieldbus interface purely for sniffing purposes only.


Max_info_frames[1-10]:

Leave at default settings.

Max_master[1-127]:

Leave this at the default settings.


Once the above settings are done, you should be able to start the BAS-o-Matic and start capturing communications from a BACnet/MSTP network.


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