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Onyxx MB311


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Lynxspring Onyxx MB311

Onyxx MB311

Lynxspring’s Helixx™ framework embedded on the Onyxx MB311 Bridge has revolutionised the construction, implementation, and interaction of Modbus to BACnet network communication. Helixx takes Modbus to BACnet protocol translation to the next level by not only translating up to 2,500/1,000 Modbus points to manageable BACnet points; it converts Modbus slave devices into virtual BACnet devices using virtual BACnet routing.

For every Modbus slave device that is added, Helixx creates a corresponding virtual BACnet device. Helixx ensures the virtual BACnet device always emulates the Modbus device it is bridging and safeguards the integrity of the BACnet network by automatically assigning a unique BACnet device instance/object ID to each virtual BACnet device used to identify it on the BACnet network.

Desired Modbus points are simply added under the Modbus slave device. Helixx automatically creates and maps the correct virtual BACnet object to its corresponding virtual BACnet device.

The Onyxx MB311 supports a maximum of 2,500/1,000 Modbus points, 32 Modbus RTU slave devices without a repeater or up to 246 with repeaters, 246 Modbus TCP slave devices per network segment, or a combination thereof. With Helixx onboard, third-party software is not needed to access and configure the Onyxx MB311 Bridge. An operator simply connects to the Onyxx MB311 Bridge utilising a standard Internet browser. Helixx presents the operator with all of the configuration screens, documentation, device settings, help, and software tools needed to complete a successful project.


Network Communication
The Onyxx MB311 is connected to a network utilising the 10/100 Mbps Ethernet port with auto-negotiation allowing for the use of either a Cat-5 straight-through cable or a crossover cable.

Modbus Serial (RTU) Communication
The optically isolated, transient protected RS-485 serial port located on the Onyxx MB311 Bridge allows for easy installation of either 2-wire (+ and -) or 3-wire (+, -, and Shield) RS-485 networks utilising the 3-screw removable terminal block.

Modbus TCP and BACnet IP Communication
Modbus TCP and BACnet IP communication occur simultaneously through the Ethernet port. Once the Onyxx MB311 Bridge is connected to a network, Modbus TCP requests are sent on registered port 502 and BACnet IP communication occurs through UDP port 0xBAC0 (decimal 47808). Both the Modbus TCP and BACnet IP ports can be modified to support the project’s needs.

Protocol Translation Capabilities
  • Modbus Serial (RTU) to BACnet IP, Modbus TCP to BACnet IP, or both Modbus Serial (RTU) and Modbus TCP to BACnet IP.
  • Bridge models available in capacities of 1000 or 2500 Modbus points to BACnet points.
  • Converts any Modbus device to a virtual BACnet device object.
Setup and Programming
  • No programming experience or third-party software tools are required.
  • Intuitive Internet browser user interface allows for easy set up and configuration.
  • Documentation and help guides are embedded on controller.
  • Flat panel and 35mm DIN rail mounting options standard.
  • 3-screw removable Optically-isolated, transient protected RS-485 serial port makes for easy 2-wire and 3-wire RS-485 network installation.
  • 10/100 Mbps Ethernet port with auto-negotiation (7ft Ethernet cable included).
  • A 15VDC 1A external power supply plugged into the barrel connector (power supply included).
  • Bright LEDs indicate power status, unit health, and transmit and receive activity.

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