HVAC Control in the New Millennium.pdf - HVAC.Amickracing

Computer Networks and Security(CAD), where DGS, and DXF file interchange protocols allow theAutoCad and Microstation CAD systems from different software vendorsto exchange graphic files.Building Automation TrendsOpen control systems using BACnet and LonTalk are becomingmore common. Product interoperability depends on the BACnetcommittee’s documents on minimum BACnet performance requirementsfor different types of equipment and the developers of LonTalk,under the LonMark trade association, developing similar performancerequirements for different types of mechanical and electrical systems.Open system product offerings include building automation systems,DDC controls, security systems and fire alarm systems. Somemanufacturers support one or both of the leading commercial protocols,BACnet and LonTalk.There are over a dozen open system protocols for building controlsystems. One of these is BACnet, which was developed under the auspicesof the American Society of Heating, Refrigerating and Air ConditioningEngineers (ASHRAE).BACnetWhen the American Society of Heating Ventilation and Air Conditioningcompleted its 8-year effort to develop the common protocol calledBACnet the goal was to establish interoperability between DCS equipmentmanufacturers. Echelon is the standard at the sensor bus level.The BACnet (Building Automation Control network) protocol allowsbuilding automation equipment from different manufacturers aminimum level of interoperability. ASHRAE began developing BACnetin 1987. It was published in 1995 as ASHRAE Standard 1355-1995.ASHRAE’S BACnet standard holds great promise for the HVAC industry.Most control manufacturers have announced their support for thestandard, and many are providing BACnet products today.BACnet is a software solution to integrating different productsfrom different manufacturers. It consists of a standardized set of messagesbetween field units and the host. BACnet is also a recognized stan-©2001 by The Fairmont Press, Inc. All rights reserved.