BACNET–MODBUS Network Gateway

The BB2-3010 is a BACnet MS/TP client/server device that functions as a Modbus RTU master/slave. A large number of BACnet objects gives you fl exibility in mapping Modbus registers to any combination of BACnet objects. Packed Modbus registers may be parsed to multiple BACnet objects when reading. Multiple BACnet objects may be packed into a single Modbus register when writing. All standard Modbus register types are supported.
Input objects will poll their assigned Modbus register at the interval you specify, and provide the Modbus data as the Present Value when read. Commandable Output objects are used to write Modbus registers, and will update the Modbus device each time BACnet is updated. The BB2-3010 supports up to 300 non-commandable objects, or up to 135 commandable objects, or a mix in between.
Value objects will poll their assigned Modbus register at the interval you specify. The content of the Modbus register will be given as the Present Value of the BACnet object when read. The Modbus register is written each time the BACnet Value object is written. The Value object corresponds to the Modbus Holding register.
The BB2-3010 is most often used as a Modbus master, but it can operate as a slave while MS/TP operates as a client (master). This makes it possible to put MS/TP devices on a Modbus network (but does still require an understanding of BACnet). MS/TP data in remote devices is queried and saved locally. The local data may then be accessed by another Modbus master.


  • User Selectable RS-422 or RS-485
  • RS-485 User Selectable 2 or 4-Wire Operation
  • Intelligent Control of RS-485 Transmitter and Receiver
  • Td and Rd LED
  • DTE/DCE Compatible
  • Data Rates up to 64k BPS
  • Connects to Standard PC Compatible 25 Pin RS-232 Port