1、BRITISH STANDARDBS EN 50494:2007Satellite signal distribution over a single coaxial cable in single dwelling installations The European Standard EN 50494:2007 has the status of a British StandardICS 33.060.30; 33.160.01g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g
2、54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 50494:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 December 2007 BSI 2007ISBN 978 0 580 57057 5National for
3、ewordThis British Standard is the UK implementation of EN 50494:2007.The UK participation in its preparation was entrusted to Technical Committee EPL/100, Audio, video and multimedia systems and equipment.A list of organizations represented on this committee can be obtained on request to its secreta
4、ry.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARD EN
5、 50494 NORME EUROPENNE EUROPISCHE NORM October 2007 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2007 CENELEC - All rights of
6、 exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 50494:2007 E ICS 33.060.30; 33.160.01 English version Satellite signal distribution over a single coaxial cable in single dwelling installations Distribution de signaux satellites sur un seul cble coaxial
7、dans les rsidences individuelles Signalverteilung von Satellitensignalen ber ein einziges koaxiales Kabelverteilnetz This European Standard was approved by CENELEC on 2007-03-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving t
8、his European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in two official version
9、s (English, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, B
10、elgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. EN 5049
11、4:2007 - 2 - Foreword This European Standard was prepared by the Technical Committee CENELEC TC 206, Consumer equipment for entertainment and information and related sub-systems. The text of the draft was submitted to the Unique Acceptance Procedure and was approved by CENELEC as EN 50494 on 2007-03
12、-01. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2008-05-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2010-03-01 _ - 3
13、 - EN 50494:2007 Contents Introduction5 1 Scope .5 2 Normative references.6 3 Acronyms and definitions .6 3.1 Acronyms6 3.2 Definitions.7 4 System architecture .7 5 SCIF control signals.10 5.1 DC levels 10 5.2 Method of the data bit signalling.11 5.3 Structure of the DiSEqC message in the single coa
14、xial cable system .11 6 Structure and format of the DiSEqC messages 12 6.1 DiSEqC addressesl12 6.2 Normal operation.12 6.2.1 ODU_Channel_change .13 6.2.2 ODU_PowerOFF 14 6.3 Special modes.14 6.3.1 Installation, SCIF parameters recognition 14 6.3.2 ODU_UBxSignal_ON16 6.3.3 ODU_Config 16 6.3.4 ODU_LoF
15、req17 7 Look-up tables and conventions17 7.1 UB slots numbering .17 7.2 Input banks numbering 18 7.3 Config_Nb table 18 7.4 LoFreq table19 8 Traffic collision management rules20 9 Optional extension of the single cable distribution to the multi-dwelling installations 22 9.1 Extension for multi-dwell
16、ing installations.22 9.2 Extensions for structure and format of the DiSEqC messages 23 9.3 Specific commands for installation (see 6.3.1 to 6.3.4) 23 9.4 Installation with manual entry of the system parameters, PIN code handling .24 9.5 SDU and MDU compatibility rules.25 Annex A (informative) Implem
17、entation guidelines 26 A.1 Installation impedance .26 A.2 Installation: signal reflection and returned loss26 A.3 Power supply of the SCIF.27 A.4 Tuning word calculation, software recommendations .28 A.5 RF scanning, RF tone recognition, SCIF parameter recognition29 EN 50494:2007 - 4 - Figures Figur
18、e 1 General architecture of the single cable distribution .6 Figure 2 General system operation and UB slot frequency mapping .8 Figure 3 Installation example, system with two UB slots 9 Figure 4 Installation example implementing a monobloc LNB with four UB slots 9 Figure 5 Example of a switcher with
19、 two outputs serving six UB slots each .10 Figure 6 Outlines of the signal sent by the receiver .11 Figure 7 Bit signalling according to DiSEqC format11 Figure 8 DiSEqC command structure 12 Figure 9 Example of signal structure delivered by the SCIF featuring four UB slots after an ODU_UBxSignal_ON.1
20、6 Figure 10 DiSEqC command collision between two receivers and recovery system .21 Figure 11 Pseudo random delay generation for the repeat operation 22 Figure 12 Example of signal spectrum delivered by a SCIF (with MDU option) after an ODU_UbxSignal_ON (or an ODU_UbxSignal_ON_MDU ) command .24 Figur
21、e A.1 Solution for masking the impedance of the installation during the DiSEqC commands.26 Figure A.2 Implementation of an external power supply .27 Figure A.3 Example of a RF spectrum found after an ODU_UBxSignal_ON.29 Tables Table 1 Automatic installation sub-functions15 Table 2 UB slot numbering.
22、17 Table 3 Input bank numbering 18 Table 4 Config_Nb table 18 Table 5 Local oscillation (LO) table in Standard RF (Conventional RF ) 19 Table 6 Local oscillation (LO) table in Wide band RF.19 Table 7 Expected system behaviour .25 - 5 - EN 50494:2007 Introduction In EN 61319-1:1995 the interfaces for
23、 the control and command of the devices associated with the satellite receivers are described in the following clauses: Clause 4: Interfaces requirements for polarizer and polar switchers; Clause 5: Interfaces requirements for low-noise block converters (LNB). In these clauses, analogue techniques a
24、re described for controlling the LNB and polar switchers. In EN 61319-1/A11, the “Digital Satellite Equipment Control Bus” (called DiSEqC) is introduced as a single method of communication between the satellite and the peripheral equipment, using only the existing coaxial cables. The purpose of this
25、 document is to introduce a complete system for distributing via a single coaxial cable signals issued from different bands and polarizations to several satellite receivers. The presented system is intended for single dwelling installation (individual subscriber installations) but in Clause 9 of thi
26、s document there is also described an optional extension for multiple dwelling installations. The presented system is scaled for installations in which the number of demodulators is limited to a maximum number of 8 units per output of the Single Cable Interface (hereafter referred to as SCIF) device
27、. 1 Scope This European Standard describes: the system physical structure; the system control signals, which implement an extension of the DiSEqC set of commands described in the DiSEqC bus functional specification; the definition of identified configurations; management of the potential collisions
28、in the control signals traffic. Figure 1 illustrates the physical system configuration considered in this European Standard. Several satellite signal demodulators can receive signals from any of the input signal banks of the LNB or the switch; the signals selected by the demodulators (or receivers)
29、are transported via a single cable to these demodulators (receiver 1, receiver 2, receiver N). To achieve these single cable distributions, the Single Cable Interface (SCIF) (likely embedded in a LNB or a Switch) features some specific functions and characteristics. EN 50494:2007 - 6 - LNB LNB orSWI
30、TCHBank 1Bank 2Bank MBanPowersplitterReceiver 1r 1Receiver NReceiver 2r 2Single cable Single caconnectionconnectionSINGLE CABLEINTERFACE: SCIFA receiver may integrate several demodulators receiver ma at dulaFigure 1 General architecture of the single cable distribution 2 Normative references The fol
31、lowing referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 50083-4 Cable networks for television signals, sound
32、signals and interactive services Part 4: Passive wideband equipment for coaxial cable networks EN 61319-1:1996 + A11:1999 Interconnections of satellite receiving equipment Part 1: Europe (IEC 61319-1:1995) EN ISO/IEC 13818-1 Information technology Generic coding of moving pictures and associated aud
33、io information Part 1: Systems (ISO/IEC 13818-1) “DiSEqCTM” Bus Functional Specification Version 4.2, February 25, 1998 http:/ 3 Acronyms and definitions 3.1 Acronyms CW Continuous Wave DiSEqC Digital Satellite Equipment Control LNB Low Noise Block LUT Look-up Table MDU Multiple Dwelling Unit MSB Mo
34、st significant bit ODU Out-door UnitPCR Program clock reference PWK Pulse Width Keying SCIF Single Cable Interface - 7 - EN 50494:2007 SDU Single Dwelling Unit UB User Band 3.2 Definitions 3.2.1 bank group of contiguous channels belonging to a polarization and or a band 3.2.2 channel radio frequency
35、 transponder signal 3.2.3 demodulator electronic device integrating at least a tuner and a demodulator 3.2.4 receiver electronic equipment embedded in a cabinet and integrating all functions for demodulating and decoding the received satellite signals, a receiver may integrate several demodulators 3
36、.2.5 universal LNB LNB with the following characteristics: operation in the Ku bands (10,7 GHz ! 12,75 GHz); local oscillator frequency is 9,75 GHz for signal frequencies lower than 11,7 GHz and local oscillator frequency is 10,6 GHz otherwise 4 System architecture In the single coaxial cable distri
37、bution system, the bandwidth of the shared coaxial cable is divided into slots (user band: UB). The number of slots Nb_ub varies from one application to another; the number of slots Nb_ub is a characteristic of the SCIF. The system defined in this standard limits the number of UB slots to 8 (eight)
38、per output of the SCIF. Each demodulator connected to the single coaxial cable distribution is allocated a UB slot; this allocation is done either in static or other modes. Static mode: the allocation of the UB slot is done during the installation of the satellite receiver. Only the static mode is c
39、onsidered in this document. Other modes are not described in this document but could be considered in a further release or annex of this document. After the slot allocation, the tuner of the receiver operates at a single frequency (centre of the slot UB). To select a desired channel (frequency Fd) t
40、he demodulator sends a SCIF control signal that provides the following information: select the bank (band, feed, polarization) that carries the desired signal. select the frequency (Fd) of the desired signal. designate the UB slot on which the desired signal is expected. Figure 2 illustrates the fre
41、quency mapping for such a single coaxial cable system. EN 50494:2007 - 8 - Figures 3, 4, and 5 illustrate various examples for implementing the single cable distribution system (other application scenarios are possible). Figure 3: a single coaxial cable distribution is implemented between a LNB and
42、two demodulators. Figure 4: a single coaxial cable distribution is implemented between a double feed LNB and a set of 4 demodulators. Figure 5: In an installation that shall serve more than 8 demodulators, a SCIF device with several outputs (Out) is implemented; each output can serve a maximum numbe
43、r of demodulators (Nb_ub). In the illustrated example, there are 2 outputs, each output can serve up to 6 demodulators, the output Out 2 could serve two additional demodulators before reaching the limit of the installed hardware. LNB orSWITCHBank 1Bank 2BankBank MPowersplittersp tterReceiver 1Receiv
44、Receiver NRe iver NReceiver 2ReceivSingle cable ngle cable connectionconnectionSINGLE CABLEINTERFACE SCIFBank 1Bank 2frequencyequencUIFinputsinputBank MBankUB_TUB_3UB_2UB_1T= Nb_ubT= Nb_Fd3Fd2Fd2Fd1UIFoutputoutFigure 2 General system operation and UB slot frequency mapping - 9 - EN 50494:2007 SCIFSC
45、IBank 2Bank 3Bank 4Bank 1Receiver 2eceiReceiver 1eceiPowersplitterlittNumber of banks = Nb_B = 4Number of user slots = Nb_ub = 2mber of user ots = _ub =Figure 3 Installation example, system with two UB slots SCIFBank 2Bank 3Bank 4Bank 1PowersplittersplitterNumber of banks = Nb_B = 8Nu _BNumber of us
46、er slots = Nb_ub = 4mber of us s ots = N _ub = 4Bank 6Bank 7Bank 8Bank 5Receiver 3eceiReceiver 2eceiReceiver 4eceiReceiver 1eceiSatellitellitASatelliteBFigure 4 Installation example implementing a monobloc LNB with four UB slots EN 50494:2007 - 10 - SCIFIF(Nb_ub=6)(NBank 2nkBank 3nkBank 4nkBank 1nkP
47、owerPowersplitterslitteDemodulator 3modulReceiver 2ReceiDemodulator 4modulReceiver 1ReceiSCIFIF(Nb_ub=6)(NReceiver 3eceiReceiver 1ReceiReceiver 2ReceiOut 1Out 2Receiver 3ReceiReceiver 4ReceiReceiver 5ReceiReceiver 6ReceiExample : system integrating 2 SCIFple : systemOn out 2, Out of 6 UB resources 4
48、 UB o 2, O t of 6 UB ur s 4 UBslots are actually used.ots are acFigure 5 Example of a switcher with two outputs serving six UB slots each 5 SCIF control signals 5.1 DC levels In a single coaxial cable distribution system, all controls issued by the receivers (demodulators) are done according to the
49、DiSEqC format. The single coaxial cable distribution system is not backwards compatible with the former 13/18 V control associated with a continuous 22 kHz tone. The single coaxial cable distribution system is also not backwards compatible with the tone burst signalling. In single coaxial cable distribution systems, the signal-sending receiver generates a high DC level upon which the DiSEqC control signals are added. After sending the DiSEqC
