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

HVAC Control in the New MillenniumBACnet and LonWorks are not interchangeable since each has itsown standardized set of messages. However BACnet messages can betransmitted across a LonWorks communication backbone. BACnet recognizesLonWorks as a physical medium only, but messages betweenLonWorks and BACnet are not interchangeable. LonMark is efficient forlow-speed, field-device communication, but does not support the highspeedexchange of data on networks like Ethernet as well as BACnet.LonMark is being applied for peer-to-peer, distributed control solutions.This type of control uses a network architecture, with a workstation,field panels, controllers, and individual devices. LonMark allowsintelligent devices to handle information and pass it on to other devices.LonMark is a cost-effective technology for interoperability at the controlslevel.LonTalk ProtocolAn open technology like the LonTalk protocol is embedded on achip. Manufacturers of different products include the chip as a standardpart of their unit.The protocol provides a set of rules for the connection and makesit cost-effective and forces the implementations to be consistent. Theprotocol chip makes it cost-effective for the manufacturers and makesevery implementation exactly the same so that there are not any differentinterpretations of a specification.Neuron-based, open-standard protocol devices are used by electricalmanufacturers and system control vendors. The equipment remainsautonomous and fault-tolerant as centrally managed programs becomedistributed throughout the LonWorks network and each Neuron devicelearns its attached equipment’s role and relation to other equipment.Electronic Systems USA is a building automation products andservices company that produces products with LonWorks technology,such as the NexSys building automation system. LonWorks allowedElectronic Systems to get to the marketplace quicker because all theprotocols are set. They did not have to develop a new system.The neuron chip is programmed with a version of the C languagecalled neuron C. It can also be programmed using drag and drop softwarefrom Dayton General Systems which allows the programming tobe done much faster.©2001 by The Fairmont Press, Inc. All rights reserved.