1、BRITISH STANDARD BS EN 13757-2:2004 Communication systems for and remote reading of meters Part 2: Physical and link layer The European Standard EN 13757-2:2004 has the status of a British Standard ICS 33.200; 35.100.10; 35.100.20 BS EN 13757-2:2004 This British Standard was published under the auth
2、ority of the Standards Policy and Strategy Committee on 2 December 2004 BSI 2 December 2004 ISBN 0 580 44959 9 National foreword This British Standard is the official English language version of EN 13757-2:2004. The UK participation in its preparation was entrusted to Technical Committee PEL/894, Re
3、mote meter reading, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI C
4、atalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its
5、 correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interest
6、s informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 28, an inside back cover and a back cover. The BSI copyright notice displayed in this docume
7、nt indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN137572 November2004 ICS33.200;35.100.10;35.100.20 Englishversion CommunicationsystemsforandremotereadingofmetersPart 2:Physicalandlinklayer Systm
8、esdecommunicationetdetlrelevdecompteurs Partie2:Couchesphysiqueetcouchedeliaison KommunikationssystemefrZhlerundderen FernablesungPhysicalundLinkLayer ThisEuropeanStandardwasapprovedbyCENon23September2004. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforg
9、ivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheCentralSecretariatortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversionin
10、anyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheCentralSecretariathasthesamestatusast heofficial versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,Cyprus,CzechRepublic,Denmark,Estonia,Finland,France, Germany,Greece,Hungary,Icela
11、nd,Ireland,Italy,Latvia,Lithuania,Luxembourg,Malta,Netherlands,Norway,Poland,Portugal, Slovakia, Slovenia,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2004CEN Allri
12、ghtsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN137572:2004:EEN 13757-2:2004 (E) 2 Contents page Foreword3 1 Scope 5 2 Normative references 5 3 Terms and definitions .5 4 Physical layer specifications6 5 Link Layer (master and slave) 12 6 Tables and figures
13、.17 Annex A (informative) Schematic implementation of slave .21 Annex B (informative) Protection against mains voltages.22 Annex C (informative) Slave powering options.23 Annex D (informative) Slave collision detect.24 Annex E (informative) Cable installation25 Annex F (informative) Protocol example
14、s27 Bibliography 28 EN 13757-2:2004 (E) 3 Foreword This document (EN 13757-2:2004) has been prepared by Technical Committee CEN/TC 294 “Communication systems for meters and remote readng of meters”, the secretariat of which is held by AFNOR. This European Standard shall be given the status of a nati
15、onal standard, either by publication of an identical text or by endorsement, at the latest by May 2005, and conflicting national standards shall be withdrawn at the latest by May 2005. This standard consists of the following parts: EN 13757-1, Communication system for meters and remote reading of me
16、ters - Part 1: Data exchange. EN 13757-2, Communication systems for and remote reading of meters - Part 2: Physical and link layer. EN 13757-3, Communication systems for and remote reading of meters - Part 3: Dedicated application layer. prEN 13757-4, Communication systems for meters and remote read
17、ing of meters - Part 4: Wireless meter readout. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Gree
18、ce, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 13757-2:2004 (E) 4 Introduction The physical and link layer parameters for baseband communication over twisted pair
19、s has first been described in EN 1434-3:1997 (“M-Bus“) for heat meters. This standard is a compatible and interworking update of a part of EN 1434-3:1997 and includes also other measured media (water, gas, heat cost allocators), the master side of the communication and newer technical developments.
20、It should be noted that the EN 1434-3:1997 covers also other communication techniques. It can be used with various application layers especially the application layer of EN 13757-3. EN 13757-2:2004 (E) 5 1 Scope This document covers the physical and link layer parameters of baseband communication ov
21、er twisted pair (M-Bus) for meter communication systems. It is especially applicable to heat meters, heat cost allocators, water meters and gas meters. NOTE It is usable also for other meters (like electricity meters) and for sensors and actuators. For generic descriptions concerning communication s
22、ystems for meters and remote reading of meters see EN 13757-1. 2 Normative references The following 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
23、 (including any amendments) applies. EN 60870-5-2, Telecontrol equipment and systems Part 5: Transmission protocols Section 2: Link transmission procedures (IEC 60870-5-2:1992). EN 61000-4-4, Electromagnetic compatibility (EMC) Part 4: Testing and measurement techniques Section 4: Electrical fast tr
24、ansient/burst immunity test Basic EMV publication (IEC 61000-4-4:1995). EN 61000-4-5, Electromagnetic compatibility (EMC) Part 4: Testing and measurement techniques Section 5: Surge immunity test (IEC 61000-4-5:1995). 3 Terms and definitions For the purposes of this document, the following terms and
25、 definitions apply. 3.1 unit load one unit load (1 U L ) is the maximum mark state current of 1,5 mA 3.2 other definitions for further definitions see 4.6 and annex C of EN 13757-1:2002 EN 13757-2:2004 (E) 6 4 Physical layer specifications 4.1 General Figure 1 shows the principal electrical concept
26、of the physical layer: Information from the master to the slaves is transmitted via voltage level changes. A (high) quiescent voltage level Umark (idle state, typically 36 V) and an active voltage level (space state) which is typically 12 V below Umark (but at least 12 V) is used for the data transm
27、ission. The high voltage step improves the noise immunity in the master to slave direction. The required minimum voltage supports continuous remote powering of all slaves of a segment. Signalling via a voltage change rather than by absolute voltage levels supports even large voltage drops due to wir
28、ing resistance of the cable installation. All slaves are constant current sinks. Their idle (mark state) current of typically 1,0 mA to 1,5 mA can be used for powering the transceiver IC in the slave and optionally also the slave (meter). The active (space state) current transmit of a slave is signa
29、lled by an increase of this constant current by (1120) mA. Signalling via constant current improves the immunity against induced voltages and is independent on wiring resistance. On the input of each slave transceiver a rectifier bridge makes each slave independent of the wiring polarity and reduces
30、 installation errors. Protective resistors in front of each slave transceiver simplify the implementation of overvoltage protection and safeguards the bus against a semiconductor short circuit in a slave by limiting the current of such a defective slave to 100 mA. Annex A shows the principal functio
31、n of a slave transceiver. Integrated slave transceivers which include a regulated buffered voltage output for slave (meter) powering, support of battery supply with supply switchover and power down signallong are commercially available. Key A Bus Voltage at Repeater B Current composition of a Slave
32、t Time m Master transmits to Slave s Slave transmits to Master Figure 1 Representation of bits on the M-Bus All specification requirements shall be held over the full range of temperature and operating voltage for the responsible system component. EN 13757-2:2004 (E) 7 4.2 Electrical requirements sl
33、ave 4.2.1 Master to slave bus voltages Maximum permanent voltage : 50 V 0 V + 50 V (no damage). Voltage range for meeting all specifications: (12 V 42 V). The Bus voltage at the slave terminals in mark-(quiescent) state of master slave communication (= U Mark ) shall be (21 V 42 V). The mark voltage
34、 shall be stored by a voltage maximum detector with an asymmetric time constant. The discharge time constant shall be greater than 30 (charge constant) but less than 1 s. The stored voltage maximum U Markmay drop in 50 ms by not more than 0,2 V for all voltages between 12 V and U Mark . Bus voltage
35、Mark/Space state for master slave communication. Space: U Bus1) and the device description shall contain a note on the multiple unit loads for this device. 4.2.2.2 Mark state bus current of a slave device The mark state current I Markshall be N unit loads. 4.2.2.3 Variation of the mark state current
36、 over bus voltage For bus voltages in the range of (12 V 42 V) a voltage variation of 1 V 15 V shall not change the bus current by more than N 3 A/V. 4.2.2.4 Short term variation of the mark state current At constant bus voltage the bus current shall not change by more than 1 % within 10 s. 4.2.2.5
37、Total variation over allowed temperature and voltage range of slave device The total variation of the mark state current of a slave device shall not vary by more than 10 % over the full voltage and temperature range of the slave device. EN 13757-2:2004 (E) 8 4.2.2.6 Max. bus current for any single s
38、emiconductor or capacitor defect 1 min after any single semiconductor or capacitor defect the max. current of any slave device shall be less than 100 mA for any bus voltage 42 V. 4.2.2.7 Slow start For any bus voltage in the range of (0 42) V the bus current shall be limited to N U L . 4.2.2.8 Fast
39、change After any bus voltage change the bus current shall be N U Lwithin 1 ms. 4.2.2.9 Space-Send current The bus current for a slave space state send shall be higher by (11 20) mA than in the mark state for all allowed bus voltages: I Space= I Mark+ (11 20) mA. 4.2.2.10 Input capacitance at the sla
40、ve terminals: 0,5 nF This capacitance shall be measured with a DC-bias of (15 to 30) V. 4.2.2.11 Startup delay In case of a bus voltage drop below 12 V for longer than 0,1 s the recovery time after applying an allowed mark state voltage until reaching full communication capabilities shall be less th
41、an 3 s. 4.2.2.12 Galvanic Isolation The isolation resistance between any bus terminal and all metal parts accessible without violating seals shall be 1 MOhm. Excluded are terminals for the connection of other floating or isolated external components. The test voltage is 500 V. For mains operated ter
42、minal devices the appropriate safety rules apply. 4.2.2.13 Optional reversible mains protection The slave interface can be equipped with an optional reversible mains protection. This guarantees that even for a prolonged period (test duration: 1 min) the slave interface can withstand mains voltages o
43、f 230 V + 10 % and 50 Hz or 60 Hz and that afterwards all specifications are met again. This mains protection function is recommended for all mains operated terminal devices. For possible implementations see annex B. 4.2.3 Dynamic requirements Any link layer or application layer protocol of up to 38
44、 400 Baud is acceptable if it guarantees that a mark state is reached for at least one bit time at least once in every 11 bit times and not later than after 50 ms. Note that this is true for any asynchronous protocol with 5 data bits to 8 data bits (with or without a parity bit) for any baud rate of
45、 at least 300 Baud, including a break signal of 50 ms. It is also true for many synchronous protocols with or without bit coding. EN 13757-2:2004 (E) 9 4.3 Electrical requirements master 4.3.1 Parameters 4.3.1.1 Max current (I Max ) A master for this physical layer is characterized by its maximum cu
46、rrent I Max . For all bus currents between zero and I Maxit shall meet all functional and parametric requirements. For example a maximally loaded segment with up to 250 slaves with 1 U Leach (375 mA) plus an allowance for one slave with a short circuit (+ 100 mA) plus the maximum space send current
47、(+ 20 mA) an I Max 0,5 A is required. 4.3.1.2 Max allowable voltage drop (U r ) The max. voltage drop U r( 0 V) is defined as the minimum space state voltage minus 12 V. U rdivided by the maximum segment resistance between the master and any terminal device (meter) gives the maximum usable bus curre
48、nt for a given combination of segment resistance and master. 4.3.1.3 Max baud rate (B Max ) Another characterisation of a master is the maximum baud rate B Maxup to which all specifications are met. The minimum baud rate is always 300 Baud. 4.3.1.4 Application description Each master device shall include a description about the required cable and device installation for proper functioning. 4.3.2 Function types 4.3.2.1 Simple level converter The master function can be realized as a logically trans
