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

Computer Networks and SecurityLonMaker for Windows is a design tool that makes it easy forcontrol and facilities managers to design and maintain LonWorks networksfor heating, ventilation and air conditioning systems. Formerlyincompatible data formats and network databases are being bridged byLonWorks technology. These systems automate equipmentreconfigurations, improve efficiency, and reduce personnel and utilitiescosts.LonWorks networks are built using the LonMaker for Windows.The Visio Technical drawing package makes up the LonMaker user interface.Dynamic Data Exchange applications, such as Microsoft’s VisualBasic or Excel, are also supported.Cisco Systems and Echelon have partnered to create a standard formerging information processing IP and LonWorks networks more fully.As the dominant router supplier, Cisco sees a future in augmenting datanetworks with LonWorks systems. Echelon is also working with SunMicrosystems to define standards for integrating Java applications withLonWorks devices using Sun’s Jini technology. Microsoft is also promotingthe merger of electrical devices with data networks in a more highlevelway, by advancing its Universal plug-and-play protocol.DeviceNetDeviceNet is a CAN-based bus developed by Allen-Bradley. It is alow-level network that connects industrial devices, such as sensors andactuators, to higher level devices such as variable-frequency drives andoperator interfaces. DeviceNet is designed as a low cost peer-to-peernetwork. Although this open industrial control networking system wasfirst sanctioned by Allen-Bradley, it is now sustained by an independentorganization, called the Open DeviceNet Vendor’s Association (ODVA).The Open DeviceNet Vendor’s Association provides free technical supportand has DeviceNet experts around the world to answer technicalquestions. DeviceNet uses the Controller Area Network (CAN) as abackbone and follows the ISO/OSI 7-Layer model.This 8-byte fieldbus system is designed for industrial I/O controlof sensors, switches and motor drives. The devices are linked togetheron a bus using a DeviceNet cable with 4 wires: Vcc, CAN-high, CANlowand Ground. The cable is shielded and has a trunk length of up to50 meters.©2001 by The Fairmont Press, Inc. All rights reserved.