* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download part_5b_LONworks - University of Florida
Survey
Document related concepts
Deep packet inspection wikipedia , lookup
Piggybacking (Internet access) wikipedia , lookup
Distributed firewall wikipedia , lookup
Wake-on-LAN wikipedia , lookup
IEEE 802.1aq wikipedia , lookup
Internet protocol suite wikipedia , lookup
Computer network wikipedia , lookup
Cracking of wireless networks wikipedia , lookup
IEEE 802.11 wikipedia , lookup
Network tap wikipedia , lookup
Zero-configuration networking wikipedia , lookup
Recursive InterNetwork Architecture (RINA) wikipedia , lookup
Airborne Networking wikipedia , lookup
Transcript
LonWorks PLC (c) 2013 R. Newman University of Florida What is LonWorks Protocol • Multiple medium protocol for home automation (domotics) and control • Local Operating Network (LON) • Narrowband PLC, TP, CX, fiber optics, RF – TP 78 kbps using Differential Manchester – PLC 5.4 or 3.6 kbps depending on frequency band • Developed by Echelon Corp. – 60 million devices by 2006 • Multiple standards – International and open industry standard – European standards – China national standards LonWorks Standards • International and open industry standard – – – – Submitted to ANSI 1999 - ANSI/CEA-709.1 Basis for IEEE 1473-L (in-train controls) SEMI (semiconductor equipment manufacturing) One of several data link/physical layers of the BACnet ASHRAE/ANSI standard for building automation. – ISO and IEC standards ISO/IEC 14908-1, -2, -3, and -4 (communications protocol, twisted pair signaling technology, power line signaling technology, and Internet Protocol (IP) compatibility) • European standards – – – – AAR electro-pneumatic braking systems for freight trains IFSF (European petrol station control) EN 14908 (European building automation standard) Part of Household Appliances Control and Monitoring – Application Interworking Specification (AIS) standards of CECED (European Committee of Domestic Equipment Manufacturers) • China national standards – Controls standard, GB/Z 20177.1-2006 – Building and intelligent community standard, GB/T 20299.4-2006 LonWorks Major Elements • • • • • LonTalk protocol Neuron chips LonWorks transceivers Network management/applications SNVTs (Standard Network Variable Types) LonTalk Protocol • Media – Twisted pair, powerline, radio frequency, fiber optics, coaxial cable – Highest data rate 1.2 Mbps • Reliability – Supports end-to-end acks with ARQ – Broadcast acks also ACK implosion problem! • Medium access – Proprietary collision prediction algorithm – Collision detection on some media (e.g., TP) – Optional priority feature • Network management/applications • SNVTs LonTalk Addressing • Hierarchical – Domain, subnet, node; also Group – All nodes in domain, subnet addressable • Channel = physical medium • Domain = logical set of nodes on one or more channels • Communication only possible in domain • Multiple domains may share channel(s) • Subnet – must share a channel – cannot span a router, 127 node max – Domain may have up to 255 subnets • Group – may use multiple channels – Node may be in up to 15 groups, <64 nodes/group – Domain may have up to 255 groups LonTalk Delivery Services • Unacknowledged – Most commonly used – Widest bandwidth • Unacknowledged/Repeated – No acks, but multiple copies sent per settings • Acknowledged – Used when reliability required – Timeout set at installation time • Priority – Time slots may be set aside for priority traffic – Used sparingly – reduces bandwidth available LonTalk Network Management • All nodes are network management capable • Find unconfigured nodes and download network addresses. • Stop, start and reset node applications • Configure routers and bridges • Download new application programs • Change the network variable configuration table: – type of protocol service used to send the network variable – whether the variable is sent in a priority slot. LonWorks Transceivers • Twisted Pair – 78 Kbps/4600 ft (1400 m) – 1.25 Mbps/430 ft (130 m) Longer distance => more attenuation => lower SNR (noise is constant) => lower data rate (Shannon's Thm) • Powerline – Spread spectrum (proprietary) or narrowband – 10 Kbps, Up to 2000 m on clear line • Radio Frequency – 400-470 MHz licensed – 900 MHz unlicensed • Configuration – Installation announces device’s presence – Binding network variable tells device what data to share with whom LonWorks Datalink Layer • • • • Error Detection (CRC) Flexible allocation of bandwidth Priority access mechanisms Graceful behavior under overload – p-persistent CSMA CSMA: When current transmission done p-persistence: Tx with prob. p Optimal p is 1/N for N contenders • Message collision avoidance • Optional collision resolution, collision detection CD not possible on RF or PLC medium => Collision avoidance important LonWorks Network Layer • Node address information • Message routing to segment – determining which nodes on the network receive various messages • Network bandwidth usage control • Routers – segment traffic – communicate between different channels LonWorks Transport Layer • • • • • • • • Broadcast addressing Unicast addressing Multicast addressing - groups Repeated service Acknowledged service Unacknowledged service Duplicate packet detection Authentication LonWorks Session Layer • Acknowledgment of received message • Application-to-application communication • Retry if the correct response is not received from the remote node • Request to a destination group and receive individual responses from the group • Request - response message authentication LonWorks Presentation Layer • Input, output, and configuration variables for the node • Standard data representations for physical quantities • Network variable description LonWorks Application Layer • Memory storage for application program • Built-in real-time operating system • Device drivers for the I/O hardware on the Neuron Chip • Standard Network Variable Types (SNVTs) SNVTs • Standard Network Variable Types • A key to interoperability • Standardizes variables used to name and describe things and their states • Maintained by LonMark International • Each standard known as an SNVT – Pronounced “snivit” – E.g., temperature is a 16-bit quantity representing -274 to 6279.5 Celcius SNVT Examples Variable Type Units Variable Type Units Switch State Boolean Temperature Degrees Celsius Device State Boolean Real Time MM,DD,YYYY Energy Kilowatt-Hours Event Count Counts Power Watts % of Full Scale Percent VoltageDC or AC RMS VolumeGallons, CCF, liters Current Amps AC, RMS Flow Gal or liters/hour Resistance Ohms Weight Kilograms, Lbs. Sound Level dBrnc Speed Miles or Km/hour VoltagedB microvolts Alphanumeric ASCII Characters Alphanumeric Kanji Characters Alphanumeric International characters Day of Week Elapsed Time Phone State Enumerated List (Mon-Sun) Second, Milliseconds, Days or Hours Enumerated List (On-hook, off-hook, busy, ringing, etc.) PressureLbs./sq.in, Pascals, Inches-Hg Relative Humidity Percent LonWorks Links • http://www.ieclon.com/LonWorks/LonWorksTuto rial.html