SIST EN 61334-5-1:2002

Distribution automation using distribution line carrier systems -- Part 5-1: Lower layer profiles - The spread frequency shift keying (S-FSK) profile

Describes the requirements of S-FSK (frequency shift keying modulation) in conjunction with the services provided by the physical layer entity and the MAC sublayer. The transmission medium is assumed to be the distribution network on both MV or LV level. To be used in conjunction with EN 61334-4-32.

Verteilungsautomatisierung mit Hilfe von Trägersystemen auf Verteilungsleitungen -- Teil 5-1: Profile der unteren Schichten - Profil für erweiterte Frequenzsprungmodulation (S-FSK)

Automatisation de la distribution à l'aide de systèmes de communication à courants porteurs -- Partie 5-1: Profils des couches basses - Profil S-FSK (modulation par saut de fréquences étalées)

Décrit les exigences de la modulation S-FSK (spread frequency shift keying - Modulation par déplacement de fréquence étalée) en relation avec les services fournis par la couche physique et la sous-couche MAC. On suppose que le réseau de distribution sur les niveaux MT et BT constitue le support de transmission. Est à lire conjointement avec la EN 61334-4-32.

Distribution automation using distribution line carrier systems - Part 5-1: Lower layer profiles - The spread frequency shift keying (S-FSK) profile (IEC 61334-5-1:2001)

General Information

• Status: Published
• Publication Date: 30-Sep-2002
• ICS: 29.240.99 - Other equipment related to power transmission and distribution networks
• ICS: 33.040.40 - Data communication networks
• ICS: 33.200 - Telecontrol. Telemetering
• ICS: 35.100.05 - Multilayer applications
• Technical Committee: PSE - Power systems management
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Oct-2002
• Due Date: 01-Oct-2002
• Completion Date: 01-Oct-2002
• Mandate: M/490 - Standardisation mandate to the European Standardisation Organisations (ESOs) to support European Smart Grid deployment
• Ref Project: EN 61334-5-1:2001 - Distribution automation using distribution line carrier systems - Part 5-1: Lower layer profiles - The spread frequency shift keying (S-FSK) profile

Overview

EN 61334-5-1:2001 - "Distribution automation using distribution line carrier systems - Part 5-1: Lower layer profiles - The spread frequency shift keying (S‑FSK) profile" specifies the lower-layer profile for Spread Frequency Shift Keying (S‑FSK) used over electrical distribution networks (MV and LV). The standard links modulation, physical layer services and Medium Access Control (MAC) sublayer behavior so manufacturers and utilities can implement interoperable distribution line carrier systems for distribution automation. It is intended to be used in conjunction with EN 61334-4-32 (LLC and higher-layer interfaces).

Keywords: EN 61334-5-1, S-FSK, distribution automation, distribution line carrier, physical layer, MAC sublayer, frequency shift keying.

Key Topics and Requirements

• S‑FSK modulation principles - definition of the spread FSK technique and spreading approach for robust signalling over distribution lines.
• Performance testing - mandatory BER and performance tests including white-noise, narrowband interferer and impulsive-noise evaluations to qualify link performance.
• Physical layer requirements - coding, bit/frame/slot timing, packet encapsulation, preamble/start delimiters, and physical-layer service primitives (e.g., P_Data.request, P_Data.indication).
• MAC sublayer specification - service definitions, MA_Data primitives (request/confirm/indication), MAC frame formats (short/long frames, subframes), and medium access control procedures tuned for S‑FSK.
• State machines and transitions - server/client physical-layer and MAC state tables and transition rules for reliable sending/receiving and synchronization.
• Normative annexes - error-value description and normative references that ensure interoperability and harmonization with related EN/IEC documents.

Practical Applications and Users

Who uses EN 61334-5-1:

• Utilities and distribution network operators deploying automated SCADA/telemetry over power lines.
• Manufacturers of line carrier modems, smart meters, remote I/O and distribution automation equipment.
• System integrators and vendors designing robust PLC layers for MV/LV networks.
• Test laboratories validating BER, interference tolerance and protocol conformance.

Typical applications:

• Remote meter reading and advanced metering infrastructure (AMI) where PLC reduces wiring costs.
• Distribution automation functions: fault detection/isolation, load control, demand response and telemetry.
• Retrofits of legacy distribution networks requiring reliable, standards-based narrowband PLC.

Related Standards

• EN/IEC 61334-4-32 (LLC / data link integration) - required companion for higher-layer services.
• Other EN/IEC 61334 parts referenced for system management and protocol models.
• EN 50065 (signalling on low-voltage electrical installations) and ISO/IEC Open Systems Interconnection references cited for interoperability.

EN 61334-5-1 is essential for anyone specifying or implementing S‑FSK line carrier solutions for utility distribution automation, providing the lower-layer rules and test methods needed for interoperable, reliable PLC deployments.

Standards Content (Sample)

Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljenoReferenčna številkaSIST EN 61334-5-1:2002(en)ICS29.240.99; 33.040.40; 35.100.05

EUROPEAN STANDARDEN 61334-5-1NORME EUROPÉENNEEUROPÄISCHE NORMJuly 2001CENELECEuropean Committee for Electrotechnical StandardizationComité Européen de Normalisation ElectrotechniqueEuropäisches Komitee für Elektrotechnische NormungCentral Secretariat: rue de Stassart 35, B - 1050 Brussels© 2001 CENELEC -All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.Ref. No. EN 61334-5-1:2001 EICS 33.200English versionDistribution automation using distribution line carrier systemsPart 5-1: Lower layer profiles –The spread frequency shift keying (S-FSK) profile(IEC 61334-5-1:2001)Automatisation de la distribution à l'aidede systèmes de communication àcourants porteursPartie 5-1: Profils des couches basses -Profil S-FSK (modulation par saut defréquences étalées)(CEI 61334-5-1:2001)Verteilungsautomatisierung mit Hilfe vonTrägersystemen auf VerteilungsleitungenTeil 5-1: Profile der unteren Schichten -Profil für erweiterte Frequenz-sprungmodulation (S-FSK)(IEC 61334-5-1:2001)This European Standard was approved by CENELEC on 2001-06-01. CENELEC members are bound tocomply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration.Up-to-date lists and bibliographical references concerning such national standards may be obtained onapplication to the Central Secretariat or to any CENELEC member.This European Standard exists in three official versions (English, French, German). A version in any otherlanguage made by translation under the responsibility of a CENELEC member into its own language andnotified to the Central Secretariat has the same status as the official versions.CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway,Portugal, Spain, Sweden, Switzerland and United Kingdom.

- 3 -EN 61334-5-1:2001Annex ZA(normative)Normative references to international publicationswith their corresponding European publicationsThis European Standard incorporates by dated or undated reference, provisions from otherpublications. These normative references are cited at the appropriate places in the text and thepublications are listed hereafter. For dated references, subsequent amendments to or revisions of anyof these publications apply to this European Standard only when incorporated in it by amendment orrevision. For undated references the latest edition of the publication referred to applies (includingamendments).NOTEWhen an international publication has been modified by common modifications, indicated by (mod), the relevantEN/HD applies.PublicationYearTitleEN/HDYearIEC 61334-1-41995Distribution automation usingdistribution line carrier systemsPart 1: General considerations –Section 4: Identification of datatransmission parameters concerningmedium and low-voltage distributionmains--IEC 61334-4-11996Part 4: Data communication protocols –Section 1: Reference model of thecommunication systemEN 61334-4-11996IEC 61334-4-321996Section 32: Data link layer - Logical linkcontrol (LLC)EN 61334-4-321996IEC 61334-4-5112000Part 4-511: Data communicationprotocols - Systems management -CIASE protocolEN 61334-4-5112000IEC 61334-4-512- 1)Part 4-512: Data communicationprotocols - Systems management usingprofile 61334-5-1-MIB--ISO/IEC 7498-11994Information technology - Open systemsinterconnection - Basic reference modelThe basic model--ISO/IEC 7498-31997Information technology - Open systemsinterconnection - Basic reference modelNaming and addressing----Signalling on low-voltage electricalinstallations in the frequency range3 kHz to 148,5 kHzPart 1: General requirements, frequencybands and electromagneticdisturbancesEN 50065-1A1A2A31991199219951996
1) To be published.
NORMEINTERNATIONALECEIIECINTERNATIONALSTANDARD61334-5-1Deuxième éditionSecond edition2001-05Automatisation de la distribution à l'aide desystèmes de communication à courants porteurs –Partie 5-1:Profils des couches basses –Profil S-FSK (modulation par sautde fréquences étalées)Distribution automation using distributionline carrier systems –Part 5-1:Lower layer profiles –The spread frequency shift keying(S-FSK) profile Commission Electrotechnique Internationale International Electrotechnical CommissionPour prix, voir catalogue en vigueurFor price, see current catalogue© IEC 2001
Droits de reproduction réservés⎯
Copyright - all rights reservedAucune partie de cette publication ne peut être reproduite niutilisée sous quelque forme que ce soit et par aucun procédé,électronique ou mécanique, y compris la photocopie et lesmicrofilms, sans l'accord écrit de l'éditeur.No part of this publication may be reproduced or utilized inany form or by any means, electronic or mechanical,including photocopying and microfilm, without permission inwriting from the publisher.International Electrotechnical Commission3, rue de Varembé
Geneva, SwitzerlandTelefax: [phone]e-mail: [e-mail] IEC web site
http://www.iec.chCODE PRIXPRICE CODEXB

61334-5-1 © IEC:2001– 3 –CONTENTSFOREWORD.71General.91.1Scope and object.91.2Normative references.91.3Definitions.112Modulation.112.1Purpose.112.2Spread frequency shift keying (S-FSK) principle.112.3Spreading.152.4Performance tests.152.4.1Purpose.152.4.2White noise BER tests.152.4.3Narrowband interferer BER tests.172.4.4Impulsive noise BER tests.173Physical layer.173.1Purpose.173.2Transmission method.173.2.1Coding.173.2.2Bit timing.173.2.3Frame timing.193.2.4Slot timing.193.3Packet encapsulation.193.3.1Purpose.193.3.2Byte and bit ordering.193.3.3Preamble and start subframe delimiter.213.3.4Pause.213.4Physical layer services definitions.213.4.1General description.213.4.2P_Data.request.233.4.3P_Data.confirm.253.4.4P_Data.indication.253.4.5P_Sync.request.273.4.6P_Sync.indication.273.5Sending and receiving physical sublayer.293.5.1Sending.293.5.2Receiving.293.5.3Synchronization – desynchronization of a server.313.5.4Physical state transition tables.333.5.5Transition table description.35

61334-5-1 © IEC:2001– 5 –4Medium access control sublayer (MAC).454.1MAC service specification.454.1.1Purpose.454.1.2Characteristics.454.1.3Overview of the services.454.1.4MA_Data.request.474.1.5MA_Data.confirm.494.1.6MA_Data.indication.514.1.7MA_Sync.indication.534.2MAC frame structure.554.2.1Frame indicator.574.2.2Long MAC frame format.574.2.3Elements of the long MAC frame.654.2.4Invalid long MAC frame.754.3Medium access control method.754.3.1Functional model.754.3.2Transmission description.774.3.3Reception description.774.3.4MAC management description.774.3.5Formal specification.774.3.6Medium access state table.794.3.7Transition table description.97Annex A (normative)
Description of error values.119Bibliography.123Figure 1 – Quality "space" similar to quality "mark".13Figure 2 – Quality "mark" much better than quality "space".13Figure 3 – Time slot and physical frame structure.19Figure 4 – P_Data services.23Figure 5 – Relationship with reference model.45Figure 6 – MA_Data service primitives.47Figure 7 – MAC subframe format.57Figure 8 – Long MAC frame made of one subframe only.59Figure 9 – Long MAC frame made of two subframes.61Figure 10 – Long MAC frame made of more than two subframes.63Table 1 – Maximum Eb/N0allowed to achieve a given BER.17Table 2 – Server physical layer transition table.33Table 3 – Client physical layer transition table.35Table 4 – Encoding and decoding of the NS field.71Table 5 – Value of the PL field.71Table 6 – MAC server state transition tables.81Table 7 – MAC client state transition table.93Table 8 – Server and client MAC management variables used in the S-FSK profile.103

61334-5-1 © IEC:2001– 7 –INTERNATIONAL ELECTROTECHNICAL COMMISSION____________DISTRIBUTION AUTOMATIONUSING DISTRIBUTION LINE CARRIER SYSTEMS –Part 5-1: Lower layer profiles –The spread frequency shift keying (S-FSK) profileFOREWORD1)The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprisingall national electrotechnical committees (IEC National Committees). The object of the IEC is to promoteinternational co-operation on all questions concerning standardization in the electrical and electronic fields. Tothis end and in addition to other activities, the IEC publishes International Standards. Their preparation isentrusted to technical committees; any IEC National Committee interested in the subject dealt with mayparticipate in this preparatory work. International, governmental and non-governmental organizations liaisingwith the IEC also participate in this preparation. The IEC collaborates closely with the InternationalOrganization for Standardization (ISO) in accordance with conditions determined by agreement between thetwo organizations.2)The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, aninternational consensus of opinion on the relevant subjects since each technical committee has representationfrom all interested National Committees.3)The documents produced have the form of recommendations for international use and are published in the formof standards, technical specifications, technical reports or guides and they are accepted by the NationalCommittees in that sense.4)
In order to promote international unification, IEC National Committees undertake to apply IEC InternationalStandards transparently to the maximum extent possible in their national and regional standards. Anydivergence between the IEC Standard and the corresponding national or regional standard shall be clearlyindicated in the latter.5)
The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for anyequipment declared to be in conformity with one of its standards.6)
Attention is drawn to the possibility that some of the elements of this International Standard may be the subjectof patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.International Standard IEC 61334-5-1 has been prepared by IEC technical committee 57:Power system control and associated communications.This second edition cancels and replaces the first edition which was issued as a technicalreport in 1996. It constitutes a technical revision and now has the status of an InternationalStandard.The text of this standard is based on the following documents:FDISReport on voting57/512/FDIS57/523/RVDFull information on the voting for the approval of this standard can be found in the report onvoting indicated in the above table.This publication has been drafted in accordance with the ISO/IEC Directives, Part 3.Annex A forms an integral part of this standard.The committee has decided that the contents of this publication will remain unchanged until 2010.At this date, the publication will bereconfirmed;withdrawn;replaced by a revised edition, oramended.

61334-5-1 © IEC:2001– 9 –DISTRIBUTION AUTOMATIONUSING DISTRIBUTION LINE CARRIER SYSTEMS –Part 5-1: Lower layer profiles –The spread frequency shift keying (S-FSK) profile1 General1.1 Scope and objectThis part of IEC 61334 describes the requirements of S-SFK (frequency shift keyingmodulation) in conjunction with the services provided by the physical layer entity and the MACsublayer. The transmission medium is assumed to be the distribution network on both MV orLV level. The MAC sublayer described in this standard interfaces with the logical link controllayer described in IEC 61334-4-32.The three parts – modulation, physical layer and MAC sublayer – are matched to each otherso that an optimum cost-performance relation can be achieved.The profile described in this standard is one of several profiles (described in seriesIEC 61334-5) which are all designed for data transmission via the distribution network.Considering the ongoing technical development in this field, the profiles are published first astechnical specifications with the intention to transform into standards those profiles which aresuccessful in practice.1.2 Normative referencesThe following normative documents contain provisions which, through reference in this text,constitute provisions of this part of IEC 61334. For dated references, subsequentamendments to, or revisions of, any of these publications do not apply. However, parties toagreements based on this part of IEC 61334 are encouraged to investigate the possibility ofapplying the most recent editions of the normative documents indicated below. For undatedreferences, the latest edition of the normative document referred to applies. Members of IECand ISO maintain registers of currently valid International Standards.IEC/TR 61334-1-4:1995, Distribution automation using distribution line carrier systems – Part 1:General considerations – Section 4: Identification of data transmission parameters concerningmedium and low voltage distribution mainsIEC 61334-4-1:1996, Distribution automation using distribution line carrier systems – Part 4:Data communication protocols – Section 1: Reference model of the communication systemIEC 61334-4-32:1996, Distribution automation using distribution line carrier systems – Part 4:Data communication protocols – Section 32: Data link layer – Logical link control (LLC)

61334-5-1 © IEC:2001– 11 –IEC 61334-4-511:2000, Distribution automation using distribution line carrier systems – Part 4-511:Data communication protocols – Systems management – CIASE protocolIEC 61334-4-512, Distribution automation using distribution line carrier systems – Part 4-512:Data communication protocols – Systems management using profile 61334-5-1 MIB 1)ISO/IEC 7498-1:1994, Information technology – Open Systems Interconnection – BasicReference Model – The Basic ModelISO/IEC 7498-3:1997, Information technology – Open Systems Interconnection – BasicReference Model – Naming and addressingEN 50065-1:1991, Signalling on low-voltage electrical installations in the frequency range3 kHz to 148,5 kHz – Part 1: General requirements, frequency bands and electromagneticdisturbances1.3 DefinitionsFor the purpose of this part of IEC 61334, the definitions of ISO/IEC 7498-1 and EN 50065-1apply.2 Modulation2.1 PurposeS-FSK is a modulation and demodulation technique which combines some of the advantagesof a classical spread spectrum system (for example, immunity against narrowband interferers)with the advantages of a classical FSK system (low-complexity, well-investigated imple-mentations).2.2 Spread frequency shift keying (S-FSK) principleThe transmitter assigns the space frequency fS to "data 0" and the mark frequency fMto "data 1".The difference between S-FSK and the classical FSK lies in the fact that fSand fMare nowplaced far from each other (spreading). By placing the signal for "space" far from the signalfor "mark", their transmission quality becomes independent (the strengths of the small-bandinterferences and the signal attenuations are both independent at the two frequencies).The receiver performs conventional FSK demodulation at the two possible frequencies (thehalf-channels) resulting in two demodulated signals dS and dM. If the average receptionquality of the two half-channels is similar (see figure 1), then the decision unit decides on thehigher of the two demodulated channels ("data 0" if dS> dM, "data 1" if dS< dM). If, however,the average reception quality of one half-channel is significantly better than the quality of theother half-channel (see figure 2), then the decision unit compares the demodulated signal ofthe better channel with a threshold T, thus ignoring the worse channel.The quality measurements and the threshold computation may be based on a predefinedpreamble which precedes the transmission of the actual data frame.________1)
To be published.
61334-5-1 © IEC:2001– 13 –Signal "mark"fMSignal "space"FrequencyNoise level for "space"similar to noise level for "mark"RECEIVERDecision unitData "1"Data "0""Space"demodulatordS> 463/01IEC
464/01
61334-5-1 © IEC:2001– 15 –2.3 SpreadingThe values for the absolute frequency deviation ⏐fM–fS⏐ should be such that the signaltransmission qualities at fMand at fS are independent of each other. Taking into account themeasurements presented in IEC 61334-1-4, it is recommended that ⏐fM–fS⏐ > 10 kHz beused.fMand fSshall be situated in the frequency band defined in EN 50065-1.2.4 Performance tests2.4.1 PurposeThe quality of the implementation is guaranteed by different performance tests. The tests canbe performed under laboratory conditions and shall be reproducible.The BER (bit error rate) measurements are made by transmitting a preamble, a framedelimiter followed by a block of 38 bytes of data. It is assumed that no frame synchronizationerrors are encountered. The BER is measured by counting the errors in the block of data.The tests which will be described in the following subclauses shall be accomplished forreceiver input signals in the range of 2 mVrms to 2 Vrms.Different kinds of interferences are added to the transmitted signal.2.4.2 White noise BER testsWhite Gaussian noise is added to the transmitted signal.N0 [W/Hz] denotes the noise power spectral density measured at the input of the receiver atfrequencies fc–fd,fc and fc+fd. It shall be ensured that the noise spectrum is flat between fc–fdand fc+fd.Eb [Ws]denotes the received signal energy per bit. Eb= V2signal(r.m.s.),where Vsignal(r.m.s.)is the true r.m.s. (root mean square) value of the transmitted signal at the receiver input. Thebandwidth of the r.m.s. voltmeter shall be such that the entire frequency range of the signal isconsidered.Because the channel may behave differently for the two transmitted frequencies (differentnoise levels and/or different attenuation) the AWGN (additive white Gaussian noise) tests aremade using different signal levels. Eb1 is the energy of the received signal if "logical 1" istransmitted, Eb0 is the energy of the received signal if "logical 0" is transmitted. The averageenergy per bit then becomes Eb= (Eb1+Eb0)/2.The ratio between the two signal energy levels is denoted as energy ratio x, wherex = Eb1/Eb0.The following Eb/N0 values shall not be exceeded while achieving the given BERs.

61334-5-1 © IEC:2001– 17 –Table 1 – Maximum Eb/N0 allowed to achieve a given BERBER–5 dB < x < 5 dBx = ±10 dBx = ±20 dB10–5Eb/N0 < 21 dBEb/N0 < 17 dBEb/N0 < 7 dB10–4Eb/N0 < 19 dBEb/N0 < 15 dBEb/N0 < 5 dB10–3Eb/N0 < 17 dBEb/N0 < 13 dBEb/N0 < 3 dB10–2Eb/N0 < 14 dBEb/N0 < 11 dBEb/N0 < 1 dB10–1Eb/N0 < 10 dBEb/N0 < 7 dBEb/N0 < –3 dB2× 10–1Eb/N0 < 8 dBEb/N0 < 4 dBEb/N0 < –5 dBNOTE
The Eb/N0 limits should serve as guidelines. They are at least 3 dB above the theoreticallyachievable values.2.4.3 Narrowband interferer BER testsOne sinusoidal interferer of frequency fN is added to the transmitted signal. The averageinterferer power is SN= V2interferer(r.m.s.). The average signal power is Ss= V2signal(r.m.s.).For SN/Ss < 30 dB, no errors shall be encountered (BER < 10–5) for any frequency20 kHz < fN < 95 kHz.2.4.4 Impulsive noise BER testsPeriodic impulsive noise with an amplitude of 5 V peak to peak, a frequency f and duty cyclesbetween 10 % and 50 % is used. The signal amplitude is set to 20 mVrms. The BER shall belower than 10–5 for f=100 Hz and f=1 000 Hz.3 Physical layer3.1 PurposeThis clause covers the services required of the DCP physical layer entity at the logicalinterfaces with the MAC sublayer. It also defines the transmission methods which are used toprovide the information flow through the physical channel (LV power distribution network).3.2 Transmission methodDistribution line signalling equipment will interface with distribution power-line wiring systemswith the following characteristics:a)AC single-phase or three-phase;b)50 Hz or 60 Hz ± 10 %;c)230 Vrms (190 Vrms min., 250 Vrms max.).3.2.1 CodingNon-return-to-zero (NRZ) coding is used.3.2.2 Bit timingAt 50 Hz, the maximum duration of a data (transmission moment) is 3,333 ms. The defined bitduration corresponds to a minimum transmission speed of 300 bits/s at 50 Hz, and 360 bits/sat 60 Hz.

61334-5-1 © IEC:2001– 19 –At the minimum transmission speed (300 bits/s or 360 bits/s), the duration of three data bitsmight correspond to the time interval between two succeeding zero crossings of one of thethree phases of the mains. When mains-synchronized, the data bits are placed in time so thatthe start of every third bit corresponds to the zero crossing of one phase. This means that bitsynchronization can be achieved by dividing the interval between two zero crossings of one ofthe three phases by three. Other transmission speeds which are multiples of 300 bits/s for50 Hz mains signal (600 bits/s, 900 bits/s, 1 200 bits/s, etc.) are possible.3.2.3 Frame timingThe PHY_frames (consisting of a preamble, a start subframe delimiter, a MAC-subframe, anda pause) are transmitted during predefined time slots (see figure 3); this means that thePHY_frames will always start at integer multiples of the basic time slot duration. These timeinstances are called slot indicators. After slot synchronization is achieved, the physical layerof each unit will keep track of the slot indicators independently by means of its internal clock.3.2.4 Slot timingFor the remote station (server), the system wide synchronization of the slot indicators isachieved by means of any subframe received using the preamble and the start delimiter.3.3 Packet encapsulation3.3.1 PurposeIn order to ensure optimum robustness against synchronization errors at the physical level aPHY_frameconsists of–a P_sdu (38 bytes) equal to the M_pdu transmitted by the MAC sublayer;– a P_pci encapsulating the P_sdu with a preceding preamble (2 bytes) followed by thesubframe delimiter (2 bytes) and a succeeding pause (3 bytes).PreambleStart subframedelimiterP_sdu = dataPausePHY - FrameSlot indicator kSlot indicator k + 12 bytes2 bytes3 bytes38 bytesFigure 3 – Time slot and physical frame structure3.3.2 Byte and bit orderingThe bytes are sent from the most significant byte (MSB) to the least significant byte (LSB).By convention, the most significant byte corresponds to the leftmost byte.Bit fields are packed with the same convention as byte fields. That is, the first bit in an octet isthe most significant (leftmost) bit.IEC
465/01
61334-5-1 © IEC:2001– 21 –3.3.3 Preamble and start subframe delimiterThe preamble is a 16-bit field equal to: AAAA (hex).The start subframe delimiter is a 16-bit field equal to: 54C7 (hex) which follows the preamble.The preamble and the start subframe delimiter form a set of four bytes which serves thefollowing purposes:a)adaptation of the automatic gain control (AGC);b)quality measurement and threshold computation (determination of the demodulationmethod);c)fine tuning of the bit synchronization (if necessary);d)frame checking: the aim is to verify that the received demodulated signal structurecorresponds to an extract of a physical frame. The checking is carried out on a part of thepreamble and start subframe delimiter fields;e)slot indicator resynchronization (if necessary).NOTE
The receiving gain (determined when receiving the preamble and start subframe delimiter field) can bebounded to a maximum value. This value is memorized in the max-receiving-gain physical management variable.3.3.4 PauseTwenty-four-bit field of no transmission.The purpose of the pause is to give the receiver time to perform decoding and dataprocessing before it has to be ready for the next frame.3.4 Physical layer services definitions3.4.1 General description3.4.1.1 The P_Data servicesThe P_Data services provided by the physical layer allow the MAC sublayer entity to transfera single M_pdu to a peer MAC sublayer entity (or entities) using the low-voltage distributionnetwork as the transport medium.There are three general P_Data service primitives and two specific P_Sync service primitivesfor local synchronization management purposes.The three general P_Data service primitives are:–P_Data.request,–P_Data.confirm,– P_Data.indication.

61334-5-1 © IEC:2001– 23 –P_Data.requestP_Data.indicationP_Data.confirmLOCAL STATIONREMOTE STATIONMACsublayerPhysicallayerPhysicallayerMACsublayerFigure 4 – P_Data services3.4.1.2
The P_Sync servicesThe P_Sync services provided by the physical layer allow the MAC sublayer entity to:–ask for a new synchronization,–be informed of a change in the synchronization state of the physical layer.There are two P_Sync primitives which are used locally by the MAC sublayer:–P_Sync.request;–P_Sync.indication.3.4.2 P_Data.request3.4.2.1
FunctionThis primitive defines the transfer of data from a local MAC sublayer entity to a single peerMAC entity or multiple peer MAC entities in the case of a group address.3.4.2.2
StructureThe semantics of the primitive are as follows:P_Data.request (P_sdu)3.4.2.3 UseThis primitive is generated by the MAC sublayer entity whenever data shall be transmitted toa peer MAC entity or entities. This can be in response to a request from higher layers ofprotocol.IEC
466/01
61334-5-1 © IEC:2001– 25 –The reception of this primitive will cause the PHY entity to construct a PHY_frame asdescribed in figure 3 and the transfer to the peer PHY layer entity or entities.3.4.3 P_Data.confirm3.4.3.1
FunctionThis primitive has only local significance and provides an appropriate response to the MACsublayer entity which initiated a P_Data.request primitive. The P_Data.confirm primitive tellsthe MAC sublayer entity how the PHY_frame of the previous P_Data.request has beentransmitted on the medium.3.4.3.2
StructureThe semantics of this primitive are as follows:P_Data.confirm (Transmission_status)The Transmission_status parameter is used to pass status information back to the localrequesting MAC sublayer entity. It is used to indicate the success or failure of the previousassociated P_Data.request. It may also indicate that the physical layer has lost its framesynchronization.The possible returned value of the Transmission_status is one of the following:–OK: no error has been found;–LP-TU: resources temporally unavailable at the PHY sublayer;–LP-NI: resources not implemented or inactivated at the physical layer;–LP-HF: hardware failure at the PHY sublayer;–LP-NS: physical layer not synchronized;–LP-SE: syntax error on the P_sdu transmitted by the MAC sublayer (length of the P_sdudifferent from 38 bytes).3.4.3.3 UseThis primitive is generated in response to a P_Data.request from the local MAC sublayerentity.It is assumed that sufficient information is available to the MAC sublayer to associate theconfirm with the appropriate request.3.4.4 P_Data.indication3.4.4.1
FunctionThis primitive defines the transfer of data from the PHY sublayer entity to the MAC sublayerentity.3.4.4.2
StructureThe semantics of this primitive are as followsP_Data.indication(P_sdu)

61334-5-1 © IEC:2001– 27 –3.4.4.3 UseThe P_Data.indication is passed from the PHY sublayer entity to the MAC sublayer entity toindicate the arrival of a frame to the local PHY sublayer entity. Such frames are reported onlyif they are properly synchronized and written in a valid format.3.4.5 P_Sync.request3.4.5.1 FunctionThis primitive has only local significance. It provides the MAC sublayer with a means to askfor a resynchronization of the physical layer.3.4.5.2 StructureThe semantics of the primitive are as follows:P_Sync.request (state)The state parameter takes only one value: state=rejected. This information is submitted to askfor a new synchronization.3.4.5.3 UseThis primitive is generated by the MAC sublayer each time a new synchronization is needed(for more details, see 4.3.6).3.4.6 P_Sync.indication3.4.6.1 FunctionThis primitive has only local significance. It informs the MAC sublayer of a synchronizationstate change at the physical layer level.3.4.6.2 StructureThe semantics of the primitive are as follows:P_Sync.indication (New Synchronization State)The New Synchronization State parameter indicates the new synchronization state of thephysical layer. It takes only one value:–SYNCHRO_FOUND: the physical layer entity has found a synchronization reference.3.4.6.3 UseThis primitive is generated by the physical sublayer entity each time a new synchronizationreference is found. No P_Sync.indication() service is returned when the synchronization lossis required by the MAC sublayer through the P_Sync.request (State=Rejected) primitive.

61334-5-1 © IEC:2001– 29 –3.5 Sending and receiving physical sublayerThe functional model is analysed from a client or server point of view. The model allowswriting and reading of the physical management variables (see 3.5.5.3) through managementprimitives.3.5.1 Sending3.5.1.1 Client sendingThe client is the master of the DLC communication. He must transmit physical frames duringpredefined time slots. The beginning of a time slot starts at time instances called slotindicators. These indicators correspond to a zero crossing of one of the three phases of themains. Each time the client physical layer finds a new slot indicator reference, it notifies it tothe MAC sublayer by providing a P_Sync.indication(SYNCHRO_FOUND) primitive.NOTE
The MAC sublayer is able to order the search of a new time slot reference thanks to the P_Sync.request(state=rejected) primitive.When the physical layer receives a P_data.request primitive from the MAC sublayer, it firstchecks the length of the received P_sdu. If this length is different from 38 bytes, a negativeP_Data.confirm is immediately returned to the MAC sublayer.If the length of the P_sdu is equal to 38 bytes, the physical layer waits for the occurrence of atime slot indicator to start the transmission. When this event appears, the physical layer firsttransmits the preamble (2 bytes equal to AAAA H) followed by the start subframe delimiter(2 bytes equal to 54C7 H) and the 38 bytes of the P_sdu issued from the MAC sublayer.Once the transmission of these 42 bytes is over, the physical layer resumes an idle statewhen it is ready for processing incoming physical frames or P_Data.request primitives.3.5.1.2 Server sendingThe server is the slave of the DLC communication. To transmit a physical frame, the servershall be synchronized with a client.If the server is synchronized with the client, the sending procedure is identical to that ofthe client.3.5.2 Receiving3.5.2.1 Client receivingIf the physical layer has not received any P_Data.request primitive in the current time slot, itautomatically enters the reception mode for the next time slot indicator occurrence.The physical layer uses the first four bytes of the received data to–stabilize the gain;–measure the quality on each half-channel and determine the decision threshold to be usedfor the reception process;–check the received demodulated signal structure.

61334-5-1 © IEC:2001– 31 –If the received demodulated signal structure corresponds to the beginning of a physical frame,the physical layer carries on the demodulation of the next 38 bytes. A P_Data.indicationprimitive is then issued to the upper MAC sublayer. It then enters the idle state, waiting for thenext time slot indicator occurrence.If the received demodulated signal structure does not correspond to the beginning of a physicalframe, it is deduced that it is noise. The physical layer immediately enters the idle state.3.5.2.2 Server receivingThe server is the slave of the DLC communication. To receive a physical frame, the servershall be synchronized with a client.The maximum gain used by the server in the receiving mode can be controlled by the clientsystem through the max-receiving-gain MIB object (see IEC 61334-4-512).If the server is synchronized with the client, the receiving procedure is identical to that ofthe client.3.5.3 Synchronization – desynchronization of a serverAn unsynchronized server always analyses the transmission channel to discover datacorresponding to the preamble (AAAAH) and the start subframe delimiter (54C7H) fields.When the physical layer finds a sequence true to the path, it notifies it to the MAC sublayer byproviding a P_Sync.indication(SYNCHRO_FOUND) primitive. It then enters the receptionmode and acquires the next 38 data bytes. A P_sdu is formed from this packet of bytes and issubmitted to the MAC sublayer.The server is supposed to have found a synchronization reference as soon as the MACsublayer receives a SYNCHRO_FOUND notification. Nevertheless, this reference is kept bythe system only if the MAC sublayer is able to observe the reception of a valid MAC frameduring a limited period called synchronization-confirmation-time-out.If no valid MAC frame is received by the MAC sublayer during this period, it is supposedthat the system found its synchronization reference on parasite signal. The MAC sublayerthen orders a desynchronization of the physical layer by sending a P_Sync.request(State=Rejected) primitive. If a valid MAC frame is received, the system considers that thesynchronization reference is correct. This reference is kept.Besides desynchronizations due to the expiration of the specific synchronization-confirmation-time-out counter, other events controlled by the MAC sublayer may cause a desynchro-nization of the system. These are:• the expiration of the time-out-frame-not-OK counter: no valid frame has been receivedduring a period of time equal to time-out-frame-not-OK seconds;• the expiration of the time-out-not-addressed counter: no personally addressed frame hasbeen received by the system during a period of time equal to time-out-not-addressedminutes;• the identification of a wrong initiator: the MAC sublayer has identified a MAC frametransmitted or designated to an unauthorized client system. The system should not besynchronized on such frames: desynchronization is then ordered;NOTE
Such an event can only occur if the system is configured in the so-called locked state. In the lockedstate, the server system only accepts synchronization on frames which are issued by, or designated to, aspecific client system called the initiator. The initiator is identified by its MAC address contained in theinitiator-mac-address MAC management variable. If this variable is set to the NO-BODY value, the serversystem works in an unlocked state.• the writing of the new-synchronization MAC management variable;• the writing of the mac-address MAC management variable (only if set to NEW).

61334-5-1 © IEC:2001– 33 –3.5.4 Physical state transition tablesTable 2 – Server physical layer transition tableInitialstateEventsActionsFinal stateConfigLocal_Status() = OKand Is_server()=TRUENoneLFSLFS orS_IDLWrite_Request()and Check_Write()<>OKWrite_Conf(P_Tstat=Check_Write())UnchangedstateLFS orS_IDLRead_Request()and Check_Read()<>OKRead_Conf(P_Tstat=Check_Read())UnchangedstateLFS orS_IDLWrite_Request(max-receiving-gain)and Check_Write()=OKSet_Value(max-receiving-gain)Write_Conf(P_Tstat=OK)UnchangedstateLFS orS_IDLRead_Request(Server-Physical-Management-Variable)and Check_Read()=OKRead_Conf(Server-Physical-Management-Variable)UnchangedstateLFS orS_IDLP_Data.request (P_sdu)and Check()<>OKP_Data.confirm (P_Tstat = Check())LFSLFSP_Sync.request(State)NoneLFSLFSSynchro_Found(Delta_Phase)Init_Time_slot()Init_Counter(synchronisation-confirmation-time-out)Set_Delta_Electrical_Phase(Delta_Phase)P_Sync.indication(SYNCHRO_FOUND)S_RPF.RS_IDLP_Sync.request (State=Rejected)NoneLFSS_IDLTime_Slot()NoneS_RPF.CS_IDLP_Data.request (P_sdu)and Check()<>OKP_Data.confirm(P_Tstat= Check())S_IDLS_IDLP_Data.request (P_sdu)and Check()=OKBuild_P_Frame (preamble = AAAAHSSD = 54C7HP_sdu)SPF.WS_RPF.CPreamble_SSD() = OKNoneS_RPF.RS_RPF.CPreamble_SSD() <> OKNoneS_IDLS_RPF.REnd_Receiving()and Sync_Conf = FALSEP_Data.indication(P_sdu)S_IDLSPF.WTime_Slot()NoneSPF.SSPF.SEnd_Sending()P_Data.confirm (P_Tstat= OK)S_IDL

61334-5-1 © IEC:2001– 35 –Table 3 – Client physical layer transition tableInitialstateEventsActionsFinalstateConfigLocal_Status() = OKand Is_server()= FALSENoneWFZCWFZCZero_Crossing()Init_Time_Slot()P_Sync.indication(SYNCHRO_FOUND)C_IDLC_IDLP_Sync.request(State=Rejected)NoneWFZCC_IDLWrite_Request()and Check_Write()<>OKWrite_Conf(P_Tstat=Check_Write())C_IDLC_IDLRead_Request()and Check_Read()<>OKRead_Conf(P_Tstat=Check_Read())C_IDLC_IDLWrite_Request(max-receiving-gain)and Check_Write()=OKSet_Value(max-receiving-gain)Write_Conf(P_Tstat=OK)C_IDLC_IDLRead_Request(max-receiving-gain)and Check_Read()=OKRead_Conf(max-receiving-gain)C_IDLC_IDLP_Data.request(P_sdu)and Check()=OKBuild_P
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