IEEE S TANDARDS
IEEE S TANDARDS
The Institute of Electrical and Electronic Engineers (IEEE) computer society established the Standards Project 802 in 1980 for the purpose of developing
a local area network standard that would allow equipment from different manufacturers to communicate through a local area network. After studying all the users’ and manufacturers’ requirements, the committee developed standards that define several types of local networks.
IEEE 802.3. The IEEE, in accordance with the ISO, agreed to be responsible for the specifications of local area networks whose transmission speeds range between 1 and 20 megabaud (megabits/sec). The IEEE 802.3 standard, which the ISO accepted as its own standard (ISO 8802), regulates layers 1 and 2A of the OSI model. Figure 18-16 illustrates the different parts of the IEEE 802 standard and its relationship to the OSI model.
IEEE 802 ISO
Relationship to Higher Layers
Layers Layers 2B
Logical
Logical Link Control Protocol
Link Control Sublayer
2A Data Link Medium
CSMA/CD
Area Network
Physical Layer 1 Layer
Physical
Relationship Between Subcategories
bps: bits per second
10M bps
1.4M bps
1M, 5M, 10M bps
4M, 20M, 40M bps
1M, 5M, 10M, 20M bps 1.544M, 5M, 10M, 20M bps Figure 18-16. IEEE 802 standard.
The IEEE 802.3 standard specifies that network access should occur through CSMA/CD using a bus topology at a rate of 1 to 20 Mbaud (baseband) or 10 Mbaud (broadband). The widely used Ethernet network complies with the IEEE 802.3 standard. In fact, when Ethernet was first developed in the early 1980s through a joint effort of Digital Equipment Corporation (DEC), Xerox,
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S ECTION Advanced PLC Local Area C HAPTER 5 Topics and Networks
Networks 18
and Intel, the IEEE accepted it with only a few modifications to make it comply with the 802.3 (CSMA/CD bus). The ISO has also taken Ethernet as
a standard, the ISO 8802.3. In control systems, the Ethernet (802.3) network is primarily suited for noncritical applications, such as supervisory monitor- ing and PLC program management.
IEEE 802.4 and 802.5. The IEEE 802.4 standard specifies a token bus network at different baseband and broadband transmission rates than the IEEE 802.3 standard. The 802.4 standard is used by many PLC manufacturers as the protocol structure of the lower layers of their local area networks. Furthermore, another IEEE standard, the IEEE 802.5, specifies a token ring network with lower transmission rates for baseband cables (1.4 Mbaud). IBM adopted the 802.5 standard for their token-passing protocol with ring topology. Figures 18-17a, b, and c illustrate the general characteristics of the IEEE 802.3, 802.4, and 802.5 standards, respectively.
Line Terminator
Transceiver Cable
Segment Local
Repeater
Station Topology: extended bus (tree structure)
Method of transmission: baseband, broadband
Data rate:
10 Mbit/sec
Coding: Manchester Access method: CSMA/CD Transmission media: special coaxial cable
Max. distance between two nodes:
2.8 km
Figure 18-17a. Characteristics of the IEEE 802.3 standard (Ethernet).
Node Station
Topology: physical bus, logical ring structure Method of transmission: carrier band, broadband
1 to 20 Mbit/sec Coding: FSK, PSK Access method: token passing Transmission media: coaxial cable, fiber optics cable
Data rate:
Max. distance between two nodes: 800 m Figure 18-17b. Characteristics of the IEEE 802.4 standard (token bus).
Industrial Text & Video Company 1-800-752-8398
www.industrialtext.com
S ECTION Advanced PLC Local Area C HAPTER 5 Topics and Networks
Networks 18
Connection Point
Trunk Coupling Unit (TCU)
Node
Medium Interface Cable
Medium Interface Connector (MIC)
Topology: physical and logical ring
Method of transmission: baseband
Data rate:
1, 4, 16 Mbit/sec
Coding: Manchester Access method: token passing Transmission media: twisted-pair cable Max. distance between two nodes: 100 m
Figure 18-17c. Characteristics of the IEEE 802.5 standard (token ring network).
Parts
» An Industrial Text Company Publication Atlanta • Georgia • USA
» C HAPTER T HREE L OGI C C ON CEPT S
» 3 -3 P RINCIPLES OF B OOLEAN A LGEBRA AND L OGIC
» 3 -4 PLC C I RCU I T S AN D L OGI C C ON TACT S Y M BOLOGY
» C ONTACT S YMBOLS U SED IN PLC S
» L OADING C O N S I D E R AT I O N S
» M E M O RY C A PA C I T Y AND U T I L I Z AT I O N
» A P P L I C AT I O N M E M O RY
» D AT A T ABLE O R G A N I Z AT I O N
» 6 -2 I /O R ACK E NCLOSURES AND T ABLE M APPING
» I /O R ACK AND T ABLE M APPING E XAMPLE
» 6 -4 P L C I NSTRUCTIONS FOR D ISCRETE I NPUTS
» 6 -6 P L C I NSTRUCTIONS F OR D ISCRETE O UTPUTS
» 7 -3 A NALOG I NPUT D ATA R E P R E S E N TAT I O N
» 7 -4 A NALOG I NPUT D ATA H ANDLING
» 7 -6 O V E RV I E W OF A NALOG O UTPUT S IGNALS
» 7 -8 A NALOG O UTPUT D ATA R E P R E S E N TAT I O N
» 7 -9 A NALOG O UTPUT D ATA H ANDLING
» C HAPTER E IGHT S PECI AL F U N CT I ON I /O AN D S ERI AL C OM M U N I CAT I ON I N T ERFACI N G
» T HERMOCOUPLE I NPUT M ODULES
» E NCODER /C OUNTER I N T E R FA C E S
» S TEPPER M OTOR I N T E R FA C E S
» S ERVO M OTOR I N T E R FA C E S
» N ETWORK I N T E R FA C E M ODULES
» S ERIAL C O M M U N I C AT I O N
» I N T E R FA C E U SES AND A P P L I C AT I O N S
» 9 -3 L ADDER D IAGRAM F O R M AT
» 9 -5 L ADDER R E L AY P ROGRAMMING L ADDER S CAN E V A L U AT I O N
» P ROGRAMMING N O R M A L LY C LOSED I NPUTS
» 9 -1 0 A RITHMETIC I NSTRUCTIONS
» 9 -1 4 N ETWORK C O M M U N I C AT I O N I NSTRUCTIONS
» L ANGUAGES AND I NSTRUCTIONS
» F UNCTION B LOCK D IAGRAM (FBD)
» S EQUENTIAL F UNCTION C H A RT S (SFC)
» P ROGRAMMING L ANGUAGE N O TAT I O N
» P ROGRAMMING N O R M A L LY C LOSED T RANSITIONS
» D IVERGENCES AND C ONVERGENCES
» -1 C ONTROL T ASK D EFINITION
» C REAT I N G F LOWCH ART S AN D O U T PU T S EQU EN CES
» C ONFIGURING THE PLC S YSTEM
» S PECIAL I NPUT D EVICE P ROGRAMMING
» S IMPLE S TA R T /S TOP M OTOR C IRCUIT
» F O RWA R D /R EVERSE M OTOR I NTERLOCKING
» AC M OTOR D RIVE I N T E R FA C E
» L ARGE R E L AY S YSTEM M O D E R N I Z AT I O N
» A NALOG I NPUT C OMPARISON AND D ATA L INEARIZATION
» A NALOG P OSITION R EADING F ROM AN LV D T
» L INEAR I N T E R P O L AT I O N OF N ONLINEAR I NPUTS
» L ARGE B AT C H I N G C ONTROL A P P L I C AT I O N
» -7 S H O RT P ROGRAMMING E XAMPLES
» -1 B ASIC M EASUREMENT C ONCEPTS D ATA I N T E R P R E TAT I O N
» I NTERPRETING C OMBINED E RRORS
» B RIDGE C IRCUIT T ECHNIQUES
» R ESISTANCE T E M P E R AT U R E D ETECTORS ( RT D S )
» -1 P ROCESS C ONTROL B ASICS
» I N T E R P R E TAT I O N OF E RROR
» T RAN SFER F U N CT I ON S AN D T RAN SI EN T R ESPON SES
» D E R I V AT I V E L APLACE T RANSFORMS
» Out () s = ( )( ) In () s Hp () s
» S ECOND -O RDER L AG R ESPONSES
» D IRECT -A CTING C ONTROLLERS
» T WO -P OSITION D ISCRETE C ONTROLLERS
» T HREE -P OSITION D ISCRETE C ONTROLLERS
» -5 P R O P O RT I O N A L C ONTROLLERS (P M ODE )
» PV () s ( 1 + Hc Hp () s () s ) = SP Hc Hp () s () s () s
» CV () t = K I ∫ 0 Edt + CV ( t = 0 )
» CV ( t = 2 ) = K I 0 Edt + ∫ CV ( t = 1 )
» -7 P R O P O RT I O N A L -I NTEGRAL C ONTROLLERS (PI M ODE )
» -8 D E R I VAT I V E C ONTROLLERS (D M ODE ) S TANDARD D E R I V AT I V E C ONTROLLERS
» -9 P R O P O RT I O N A L -D E R I VAT I V E C ONTROLLERS (PD M ODE )
» -1 2 C ONTROLLER L OOP T UNING
» Z IEGLER –N ICHOLS O PEN -L OOP T UNING M ETHOD
» I TA E O PEN -L OOP T UNING M ETHOD
» S O F T WA R E T UNING M ETHODS
» R ULE -B ASED K NOWLEDGE R E P R E S E N T AT I O N
» S T AT I S T I C A L AND P ROBABILITY A N A LY S I S
» -1 I NTRODUCTION TO F UZZY L OGIC
» -2 H I S T O RY OF F UZZY L OGIC
» -3 F UZZY L OGIC O P E R AT I O N
» F U Z Z I F I C AT I O N C OMPONENTS
» F UZZY P ROCESSING C OMPONENTS
» D E F U Z Z I F I C AT I O N C OMPONENTS
» S YSTEM D ESCRIPTION AND O P E R AT I O N
» M EMBERSHIP F UNCTIONS AND R ULE C R E AT I O N
» IF A = PS AND B = NS THEN C = ZR IF A = PS AND B = NS THEN D = NS
» C HAPTER N INETEEN I /O B US N ET WORK S
» -4 D EVICE B US N ETWORKS B YTE -W IDE D EVICE B US N ETWORKS
» B IT -W IDE D EVICE B US N ETWORKS
» F IELDBUS P ROCESS B US N ETWORK
» P ROFIBUS P ROCESS B US N ETWORK
» I /O B US N ETWORK A DDRESSING
» P ANEL E NCLOSURES AND S YSTEM C OMPONENTS
» -3 N OISE , H E AT , AND V O LTA G E R EQUIREMENTS
» T ROUBLESHOOTING PLC I NPUTS
» -2 P L C S IZES AND S COPES OF A P P L I C AT I O N S
» I NPUT /O UTPUT C O N S I D E R AT I O N S
» C ONTROL S YSTEM O R G A N I Z AT I O N
» E Q U I VA L E N T L ADDER /L OGIC D IAGRAMS
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