LonWorks
Encyclopedia
LonWorks is a networking platform specifically created to address the needs of control applications. The platform is built on a protocol created by Echelon Corporation
Echelon Corporation
Echelon Corporation is an American company which designs control networks to connect machines and other electronic devices, for the purposes of sensing, monitoring and control....

 for networking devices over media such as twisted pair
Twisted pair
Twisted pair cabling is a type of wiring in which two conductors are twisted together for the purposes of canceling out electromagnetic interference from external sources; for instance, electromagnetic radiation from unshielded twisted pair cables, and crosstalk between neighboring pairs...

, powerlines
Power line communication
Power line communication or power line carrier , also known as power line digital subscriber line , mains communication, power line telecom , power line networking , or broadband over power lines are systems for carrying data on a conductor also used for electric power transmission.A wide range...

, fiber optics, and RF
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...

. It is used for the automation of various functions within buildings such as lighting
Lighting
Lighting or illumination is the deliberate application of light to achieve some practical or aesthetic effect. Lighting includes the use of both artificial light sources such as lamps and light fixtures, as well as natural illumination by capturing daylight...

 and HVAC
HVAC
HVAC refers to technology of indoor or automotive environmental comfort. HVAC system design is a major subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer...

; see Intelligent building.

Origins and uptake

The technology has its origins with chip designs, power line and twisted pair, signaling technology, routers, network management software, and other products from Echelon Corporation
Echelon Corporation
Echelon Corporation is an American company which designs control networks to connect machines and other electronic devices, for the purposes of sensing, monitoring and control....

. In 1999 the communications protocol (then known as LonTalk
LonTalk
LonTalk is a protocol optimized for control created by Echelon Corporation for networking devices over media such as twisted pair, powerlines, fiber optics, and RF...

) was submitted to ANSI
American National Standards Institute
The American National Standards Institute is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organization also coordinates U.S. standards with international...

 and accepted as a standard for control networking (ANSI/CEA-709.1-B). Echelon's power line and twisted pair signaling technology was also submitted to ANSI for standardization and accepted. Since then, ANSI/CEA-709.1 has been accepted as the basis for IEEE 1473-L (in-train controls), AAR
Association of American Railroads
The Association of American Railroads is an industry trade group representing primarily the major freight railroads of North America . Amtrak and some regional commuter railroads are also members...

 electro-pneumatic braking systems for freight trains, IFSF
International Forecourt Standards Forum
The International Forecourt Standards Forum is a UK-based European organisation which designs standards for connecting devices on a service station forecourt, such as dispensers, Tank Level Gauges, Price Signs, Car Washes and Outdoor Payment Terminals...

 (European petrol station control), SEMI
Semiconductor Equipment and Materials International
Semiconductor Equipment and Materials International is a trade organization of manufacturers of equipment and materials used in the fabrication of semiconductor devices such as integrated circuits, transistors, diodes, and thyristors...

 (semiconductor equipment manufacturing), and in 2005 as EN 14908 (European building automation standard). The protocol is also one of several data link/physical layers of the BACnet
BACnet
BACnet is a communications protocol for building automation and control networks. It is an ASHRAE, ANSI, and ISO standard protocol....

 ASHRAE
American Society of Heating, Refrigerating and Air-Conditioning Engineers
The American Society of Heating, Refrigerating and Air Conditioning Engineers is an international technical society for all individuals and organizations interested in heating, ventilation, air-conditioning, and refrigeration...

/ANSI standard for building automation
Building automation
Building automation describes the functionality provided by the control system of a building. A building automation system is an example of a distributed control system...

.

China ratified the technology as a national controls standard, GB/Z 20177.1-2006 and as a building and intelligent community standard, GB/T 20299.4-2006; and in 2007 CECED, the European Committee of Domestic Equipment Manufacturers, adopted the protocol as part of its Household Appliances Control and Monitoring – Application Interworking Specification (AIS) standards.

During 2008 ISO
International Organization for Standardization
The International Organization for Standardization , widely known as ISO, is an international standard-setting body composed of representatives from various national standards organizations. Founded on February 23, 1947, the organization promulgates worldwide proprietary, industrial and commercial...

 and IEC
International Electrotechnical Commission
The International Electrotechnical Commission is a non-profit, non-governmental international standards organization that prepares and publishes International Standards for all electrical, electronic and related technologies – collectively known as "electrotechnology"...

 have granted the communications protocol, twisted pair signaling technology, power line signaling technology, and Internet Protocol (IP) compatibility standard numbers ISO/IEC 14908-1, -2, -3, and -4.

Usage

By 2010 approximately 90 million devices were installed with LonWorks technology. Manufacturers in a variety of industries including building, home, street lighting, transportation, utility, and industrial automation have adopted the platform as the basis for their product and service offerings. Statistics as to the number of locations using the LonWorks technology are scarce, but it is known that products and applications built on top of the platform include such diverse functions as embedded machine control, municipal and highway/tunnel/street lighting, heating and air conditioning systems, intelligent electricity metering, subway train control, stadium lighting and speaker control, security systems, fire detection and suppression, and newborn location monitoring and alarming.

Technical details

Two physical-layer signaling technologies, twisted pair
Twisted pair
Twisted pair cabling is a type of wiring in which two conductors are twisted together for the purposes of canceling out electromagnetic interference from external sources; for instance, electromagnetic radiation from unshielded twisted pair cables, and crosstalk between neighboring pairs...

 "free topology" and power line carrier, are typically included in each of the standards created around the LonWorks technology. The two-wire layer operates at 78 kbit/s using differential Manchester encoding
Differential Manchester encoding
Differential Manchester encoding, also called biphase mark code or FM1, is a line code in which data and clock signals are combined to form a single 2-level self-synchronizing data stream. It is a differential encoding, using the presence or absence of transitions to indicate logical value...

, while the power line achieves either 5.4 or 3.6 kbit/s, depending on frequency.

Additionally, the LonWorks platform uses an affiliated IP
Internet Protocol
The Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...

 tunneling standard—ISO/IEC 14908-4 (ANSI/CEA-852) -- in use by a number of manufacturers to connect the devices on previously deployed and new LonWorks platform-based networks to IP-aware applications or remote network-management tools. Many LonWorks platform-based control applications are being implemented with some sort of IP integration, either at the UI/application level or in the controls infrastructure. This is accomplished with web services or IP-routing products available in the market.

An Echelon Corporation-designed IC
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...

 consisting of several 8-bit processors, the "Neuron chip" was initially the only way to implement a LonTalk protocol node and is used in the large majority of LonWorks platform-based hardware. Since 1999, the protocol has been available for general-purpose processors: a port of the ANSI/CEA-709.1 standard to IP-based or 32-bit chips.

Applications using LonWorks

  • Semiconductor
    Semiconductor device
    Semiconductor devices are electronic components that exploit the electronic properties of semiconductor materials, principally silicon, germanium, and gallium arsenide, as well as organic semiconductors. Semiconductor devices have replaced thermionic devices in most applications...

     manufacturing
    Manufacturing
    Manufacturing is the use of machines, tools and labor to produce goods for use or sale. The term may refer to a range of human activity, from handicraft to high tech, but is most commonly applied to industrial production, in which raw materials are transformed into finished goods on a large scale...

  • Lighting control system
    Lighting control system
    A lighting control system consists of a device that controls electric lighting and devices, alone or as part of a daylight harvesting system, for a public, commercial, or residential building or property, or the theater...

    s
  • Energy management system
    Energy management system
    An energy management system is a system of computer-aided tools used by operators of electric utility grids to monitor, control, and optimize the performance of the generation and/or transmission system...

    s
  • Heating/ventilation/air-conditioning systems
    HVAC
    HVAC refers to technology of indoor or automotive environmental comfort. HVAC system design is a major subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer...

  • Security systems
  • Home automation
    Home automation
    Home automation is the residential extension of "building automation". It is automation of the home, housework or household activity. Home automation may include centralized control of lighting, HVAC , appliances, and other systems, to provide improved convenience, comfort, energy efficiency and...

  • Consumer appliance controls
    Home appliance
    Home appliances are electrical/mechanical machines which accomplish some household functions, such as cooking or cleaning. Home appliances can be classified into:*Major appliances, or White goods*Small appliances, or Brown goods...

  • Public street lighting, monitoring, and control
    Street light
    A street light, lamppost, street lamp, light standard, or lamp standard is a raised source of light on the edge of a road or walkway, which is turned on or lit at a certain time every night. Modern lamps may also have light-sensitive photocells to turn them on at dusk, off at dawn, or activate...

  • Petrol station control
  • Rail Electronically Controlled Pneumatic Braking

SNVTs (Standard Network Variable Types)

One of the keys to the interoperability of the system is the standardisation of the variables used to describe physical things to LonWorks, this standards list is maintained by LonMark International and each standard is known as Standard Network Variable Types (SNVTs, pronounced "sniv-its") so for example a thermostat using the temperature SNVT is expected to produce a number between zero and 65535 that equates to a temperature between -274
Absolute zero
Absolute zero is the theoretical temperature at which entropy reaches its minimum value. The laws of thermodynamics state that absolute zero cannot be reached using only thermodynamic means....

and 6279.5 degrees Celsius.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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