2004-09-09 - ABB has become the first drives manufacturer to offer support for the BACnet communications protocol. This is now a standard feature of the company’s HVAC drives.
BACnet has been developed specifically for building services applications and is used extensively in continental Europe as well as in the United States. It is increasingly being adopted by leading BMS manufacturers.
The protocol offers “plug-and-play” integration of devices in building services. This makes it similar to the Lonworks protocol already available, but unlike Lonworks, there is no licence fee payable by the individual user, reducing the cost for the system.
Open systems, like BACnet and Lonworks, offer easy integration of devices from different manufacturers and provide more effective data transfer than hardwired points, which can only transmit an “on” or “off” value. BACnet is one of the most accessible of all the open systems on the market, giving more scope for future development. All BACnet devices communicate in the same language, without the expense of additional hardware and gateways.
“The absence of gateways makes the connection more direct,” says Nick Thorne, HVAC sales manager at ABB. “Real-time serial communications means better information, enabling operators to make better energy-management decisions. With a PC and an Internet browser, you can monitor and modify the operation of your HVAC system from wherever you are.”
BACnet has been designed to provide all the services needed by a building automation system. Having the drive communicating in native BACnet code means it can be integrated easily and seamlessly into the overall system. In the past, drives could only be connected to a BMS system through a gateway, a translator module that had to be programmed on a point-by-point basis. Alternatively, drives could be hard-wired into the system, which provided for basic control and monitoring. ABB’s BACnet enabled drives, on the other hand, can be directly connected to the BACnet system and take advantage of advanced features like auto-discovery, dynamic binding, time synchronization, and read/write variable requests. This means that the end user of a native BACnet drive will get better control at a lower installed price.
Products approved for BACnet are listed on the website of the BACnet Manufacturers Association, www.bacnetassociation.org.
BACnet is embedded with the standard RS485 interface of the ABB standard drive for HVAC. Other protocols supported by the drive are Modbus, FLN, N2 Metasys, Profibus-DP, Interbus, Lonworks, CANopen, DeviceNet, Modbus Plus, ControlNet and Ethernet.