1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationFibre optic communication subsystem test proceduresPart 2-1: Digital systems Receiver sensitivity and overload measurementBS EN 61280-2-1:2010National forewordThis British Standa
2、rd is the UK implementation of EN 61280-2-1:2010. It isidentical to IEC 61280-2-1:2010. It supersedes BS EN 61280-2-1:1999 whichis withdrawn.The UK participation in its preparation was entrusted by Technical CommitteeGEL/86, Fibre optics, to Subcommittee GEL/86/3, Fibre optic systems andactive devic
3、es.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions of acontract. Users are responsible for its correct application. BSI 2010ISBN 978 0 580 62668 5ICS 33.180.01Compliance with a
4、British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of the StandardsPolicy and Strategy Committee on 30 June 2010.Amendments issued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS EN 61280-2-1:2010EUROPEAN STANDARD EN 6
5、1280-2-1 NORME EUROPENNE EUROPISCHE NORM May 2010 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels 2010 CENELEC - All rights of explo
6、itation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61280-2-1:2010 E ICS 33.180.01 Supersedes EN 61280-2-1:1999English version Fibre optic communication subsystem test procedures - Part 2-1: Digital systems - Receiver sensitivity and overload measurement (IEC 612
7、80-2-1:2010) Procdures dessai des sous-systmes de tlcommunications fibres optiques - Partie 2-1: Systmes numriques - Mesure de la sensibilit et de la surcharge dun rcepteur (CEI 61280-2-1:2010) Prfverfahren fr Lichtwellenleiter-Kommunikationsuntersysteme - Teil 2-1: Prfverfahren fr digitale Systeme
8、- Messung der Empfindlichkeitsschwelle und der maximalen Eingangsleistung von Empfngern (IEC 61280-2-1:2010) This European Standard was approved by CENELEC on 2010-04-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this Euro
9、pean 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 three official versions (Eng
10、lish, French, 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,
11、 Belgium, Bulgaria, Croatia, 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 Kingd
12、om. EN 61280-2-1:2010 - 2 - Foreword The text of document 86C/881/CDV, future edition 2 of IEC 61280-2-1, prepared by SC 86C, Fibre optic systems and active devices, of IEC TC 86, Fibre optics, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 61280-2-1 on 2010-04-01.
13、This European Standard supersedes EN 61280-2-1:1999. The main changes with respect to EN 61280-2-1:1999 are listed below: revised to include the requirements associated with data communication equipment, regenerators and amplifiers; the term “jumper lead” has been replaced by “test cord”: a section
14、for definitions has been added; a section on measurement uncertainties has been added. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent rights. Th
15、e 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) 2011-01-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2013-04-01 _ Endorsemen
16、t notice The text of the International Standard IEC 61280-2-1:2010 was approved by CENELEC as a European Standard without any modification. _ BS EN 61280-2-1:2010 2 61280-2-1 IEC:2010(E) CONTENTS 1 Scope and object5 2 Terms and definitions .5 3 Apparatus.6 3.1 General .6 3.2 BER test set 6 3.2.1 Dat
17、a generator 7 3.2.2 Error counter .7 3.3 Optical power meter 7 3.4 Variable optical attenuator.7 3.5 Optical splitter .7 3.6 Test cords .7 3.7 Optical transmit interface.7 4 Equipment under test (EUT) .8 5 Test procedure .8 5.1 Operating conditions and test environment8 5.2 Connector end-face cleani
18、ng.8 5.3 Measurement of input sensitivity .8 5.3.1 Optical input power calibration.10 5.3.2 BER or EBR determination10 5.4 Measurement of overload level11 5.4.1 Power level calibration.11 5.4.2 Overload level determination .12 5.4.3 Calculation of overload level12 6 Measurement uncertainties.13 7 Te
19、st results 13 7.1 Required information .13 7.2 Available information.13 Bibliography14 Figure 1 Optical fibre system .5 Figure 2 Setup for the measurement of input sensitivity of a receive terminal.9 Figure 3 Setup for the measurement of input sensitivity of an amplifier or regenerator .9 Figure 4 S
20、etup for the measurement of overload level for a receive terminal11 Figure 5 Setup for the measurement of overload level for an amplifier or regenerator 12 Table 1 Minimum monitoring time.10 BS EN 61280-2-1:201061280-2-1 IEC:2010(E) 5 FIBRE OPTIC COMMUNICATION SUBSYSTEM TEST PROCEDURES Part 2-1: Dig
21、ital systems Receiver sensitivity and overload measurement 1 Scope and object This part of IEC 61280 describes the test procedures applicable to digital fibre optic communication and data systems. The object of this test procedure is to measure the minimum and maximum optical powers required and all
22、owed at the optical input port of a fibre optic system to ensure its operation within specified limits. Another objective is to verify that the guaranteed error performance is obtained at the minimum and the maximum optical input powers specified by the terminal equipment manufacturer. Figure 1 show
23、s the typical elements associated with optical fibre systems. Optical amplifiers or regenerators may be used in long haul telecom systems, but are not usually associated with data transport systems such as Ethernet, etc. In bi-directional systems the transmitter and corresponding receiver are usuall
24、y co-located, as indicated by the dotted lines. This specification is concerned with the characteristics of the optical input interface of the receiver, amplifier or regenerator shown. Measurement PointOptical Fibre LinkSystemOutput OpticalReceiveInterfaceReceiveEquipmentSystemInput OpticalTransmitI
25、nterfaceTransmitEquipmentOpticalAmplifier/Regen.Optical Fibre LinkOptical Fibre LinkOpticalReceiveInterfaceReceiveEquipmentSystemOutput SystemInput OpticalTransmitInterfaceTransmitEquipmentOpticalAmplifier/Regen.Optical Fibre LinkMeasurement PointFigure 1 Optical fibre system It should be noted that
26、 the performance of fibre optic receivers may differ for different signal formats. It is therefore necessary to use the signal format that represents actual operating conditions. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. IEC 469/10 BS EN 61
27、280-2-1:2010 6 61280-2-1 IEC:2010(E) 2.1 bit error ratio (BER) the number of errored bits divided by the total number of bits, over some stipulated period of time IEC 61931, definition 2.9.33 2.2 bit sequence a defined sequence of ones (1) and zeros (0) in a digital signal 2.3 bit pattern a predeter
28、mined sequence of 1s and 0s in a digital signal which is repeated at regular intervals 2.4 errored block ratio (EBR) the number of errored blocks, containing a defined number of digits, divided by the total number of blocks received in a specified period of time. An errored block may contain more th
29、an one errored bit 2.5 overload level the maximum input power above which a specified quality of performance is no longer achieved 2.6 pseudo random binary sequence (PRBS) a repeated bit sequence which simulates a random pattern of 1s and 0s. It is generated by the addition of the rthpreceding digit
30、 of a sequence of n bits and eliminating the sequence of n 0s (or n 1s). The pattern repeats after 2n-1 bits 2.7 receiver sensitivity the minimum power required to achieve a specified quality of performance IEC 61931, definition 2.7.58, modified 2.8 system input and output signals for the purpose of
31、 this specification, the system input and output are defined as signals which interface with external equipment. These signals have specified formats specific to the application and may be electrical or optical. The signals are accessed via physical interfaces that are specific to the equipment 3 Ap
32、paratus 3.1 General The test setup is shown in Figure 2. It is important that test cords 3 and 4 are of a similar type and make and are of equal length. 3.2 BER test set The BER test set is made up of the elements described here. BS EN 61280-2-1:201061280-2-1 IEC:2010(E) 7 3.2.1 Data generator The d
33、ata generator of the BER test set shall be capable of providing a data input to the system which may be a pseudo-random sequence or otherwise specified bit pattern with the signal format (pulse shape, amplitude, etc.) that is consistent with the requirements at the system input interface of the EUT.
34、 As a minimum requirement the data generator shall be capable of providing the following output date formats; other data formats may be used in compliance with the system requirements. a 223-1 pseudo-random data stream; an all 1 data stream; a 1 + 15 zeros data stream. The format (pulse shape, ampli
35、tude, etc.) of the test signal shall be compliant with that required at the transmit input interface. The receiver portion of the test equipment shall be able to interface with the system output for the measurement of digital errors. 3.2.2 Error counter The error counter of the BER test set shall be
36、 able to interface with the output of the EUT. It shall be capable counting single errors or errored blocks at the data rate of system output interface of the EUT. If the error counter has the facility for computing the BER or EBR value it must be capable of calculating a value as low as 1012. 3.3 O
37、ptical power meter The optical power meter used shall have a resolution of at least 0,1 dB, shall be data format and bit rate independent and shall have been calibrated for the wavelength and power range of operation for the equipment to be tested. All measurements shall be recorded on the dB scale.
38、 3.4 Variable optical attenuator The optical attenuator shall be capable of attenuation in steps less than or equal to 0,25 dB and should be able to provide a total attenuation that is at least 5 dB greater than the specified input range of the receiver under test. Care should be taken to avoid back
39、 reflection into the transmitter. 3.5 Optical splitter The optical splitter (coupler) shall have one input port and two output ports equipped with appropriate connectors. The splitting ratio for the output ports should be 50 % 0,1 dB (unless otherwise specified). 3.6 Test cords Single-mode or multim
40、ode fibre reference test cords and fitted with the appropriate connectors as required by the application shall be used, unless otherwise agreed. The optical loss of the test cords including connectors shall not exceed 1,0 dB. 3.7 Optical transmit interface The optical transmit interface shall have e
41、lectrical and optical characteristics similar to those of transmitters that are used in the specified fibre optic terminal devices, except that the output power shall exceed the maximum specified input power of the receiver by at least 2 dB. BS EN 61280-2-1:2010 8 61280-2-1 IEC:2010(E) 4 Equipment u
42、nder test (EUT) The EUT shall be a fibre optic receiver, optical amplifier or optical regenerator, including all associated signal conditioning, processing and multiplexing equipment used in the system under normal operating conditions. The system input and output terminations shall be those normall
43、y seen by the user of the system. 5 Test procedure The test procedure consists of the following steps. 5.1 Operating conditions and test environment Unless otherwise specified, normal operating conditions apply. The ambient or reference point temperature and humidity shall be specified. Switch on th
44、e EUT and all test equipment (apply any special operating conditions to the EUT if required) and allow 30 min. (unless otherwise specified) for the equipment to reach a steady-state temperature and performance condition. 5.2 Connector end-face cleaning Whenever optical connections are changed, the e
45、nd faces of the connectors shall be cleaned. Cleaning equipment (including apparatus, materials, and substances) and the methods to be used shall be suitable for the connectors to be cleaned. Connector suppliers instructions shall be consulted where doubt exists as to the suitability of particular e
46、quipment and cleaning methods. 5.3 Measurement of input sensitivity Connect the equipment as shown in Figure 2, if terminal equipment is tested, or Figure 3, if an amplifier or regenerator is tested, and set the data generator and error counter to operate with a pseudo random sequence with word leng
47、th of 223-1 (unless otherwise specified). BS EN 61280-2-1:201061280-2-1 IEC:2010(E) 9 Figure 2 Setup for the measurement of input sensitivity of a receive terminal Figure 3 Setup for the measurement of input sensitivity of an amplifier or regenerator DataGeneratorErrorCounterError Measuring SetOptic
48、alAttenuatorOpticalTransmitInterfaceOpticalSplitterOpticalPower MeterOpticalTest cordOpticalTest cordOpticalTest cordOpticalTest cord1234Amplifier/RegeneratorUnder TestReceiveEquipmentOpticalAttenuatorDataGeneratorOpticalTransmitInterfaceEquipmentUnder TestErrorCounterOpticalSplitterOpticalPower Met
49、erError Measuring SetOpticalTest cordOpticalTest cordOpticalTest cordOpticalTest cord1234IEC 470/10 IEC 471/10 BS EN 61280-2-1:2010 10 61280-2-1 IEC:2010(E) 5.3.1 Optical input power calibration This procedure shall be carried out as follows: a) Disconnect the optical power meter from the output of optical test cord 4 and disconnect the output of optical test cord 3 from the EUT. b) Connect the optical power meter to the output of opti
