SIST EN 14908-2:2014

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Odprta izmenjava podatkov v avtomatizaciji stavb in izvršnih elementov ter pri upravljanju stavb - Protokol regulacijske mreže - 2. del: Komunikacija zavitega paraFirmenneutrale Datenkommunikation für die Gebäudeautomation und Gebäudemanagement - Gebäudedatennetzprotokoll - Teil 2: Kommunikation über paarig verdrillte LeitungenRéseau ouvert de communication de données pour l'automatisation, la régulation et la gestion technique du bâtiment - Protocole de contrôle du réseau - Partie 2 : Communication par paire torsadéeOpen Data Communication in Building Automation, Controls and Building Management - Control Network Protocol - Part 2: Twisted Pair Communication97.120Avtomatske krmilne naprave za domAutomatic controls for household use35.240.99IT applications in other fieldsICS:Ta slovenski standard je istoveten z:EN 14908-2:2014SIST EN 14908-2:2014en,fr,de01-julij-2014SIST EN 14908-2:2014SLOVENSKI
STANDARDSIST EN 14908-2:20061DGRPHãþD



SIST EN 14908-2:2014



EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 14908-2
April 2014 ICS 35.240.99; 91.140.01; 97.120 Supersedes EN 14908-2:2005English Version
Open Data Communication in Building Automation, Controls and Building Management - Control Network Protocol - Part 2: Twisted Pair Communication
Réseau ouvert de communication de données pour l'automatisation, la régulation et la gestion technique du bâtiment - Protocole de contrôle du réseau - Partie 2 : Communication par paire torsadée
Offene Datenkommunikation für die Gebäudeautomation und Gebäudemanagement - Gebäude-Netzwerk-Protokoll
-Teil 2: Kommunikation über verdrillte Zweidrahtleitungen This European Standard was approved by CEN on 12 April 2013.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this 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 CEN-CENELEC Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
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COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
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B-1000 Brussels © 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 14908-2:2014 ESIST EN 14908-2:2014



EN 14908-2:2014 (E) 2 Contents
Foreword . 3 Introduction . 4 1 Scope . 5 2 Normative references . 5 3 Network overview . 5 4 System specifications . 5 4.1 General aspects . 5 4.2 Cable . 5 4.3 Topology . 5 4.3.1 Free or bus topology . 5 4.3.2 Repeater . 6 4.4 Cable termination. 6 4.4.1 Free-topology segment . 6 4.4.2 Bus topology segment . 6 4.5 Segment configuration . 6 4.6 Power specifications . 7 5 Link power . 7 5.1 General . 7 5.2 Source . 7 5.3 Power supply requirements . 8 5.4 Passive coupler circuit . 10 6 Node specifications . 12 6.1 Link power . 12 6.2 Hot plugging . 12 6.3 Transmitter/receiver interface to the MAC sub-layer . 12 6.3.1 Physical layer protocol data unit . 12 6.3.2 Frame format . 12 6.3.3 Transmit waveform . 13 6.4 Impedance . 15 7 Communication parameters . 16 Annex A (informative)
Environmental specifications . 18 Bibliography . 19 SIST EN 14908-2:2014



EN 14908-2:2014 (E) 3 Foreword This document (EN 14908-2:2014) has been prepared by Technical Committee CEN/TC 247 “Building Automation, Controls and Building Management”, the secretariat of which is held by SNV. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by October 2014 and conflicting national standards shall be withdrawn at the latest by October 2014. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 14908-2:2005. This European Standard is part of a series of standards for open data transmission in building automation, control and in building management systems. The content of this European Standard covers the data communications used for management, automation/control and field functions. EN 14908-2 is part of a series of European Standards under the general title Control Network Protocol (CNP), which comprises the following parts: Part 1: Protocol stack; Part 2: Twisted pair communication; Part 3: Power line channel specification; Part 4: IP-Communication; Part 5: Implementation; Part 6: Application elements. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. SIST EN 14908-2:2014



EN 14908-2:2014 (E) 4 Introduction This European Standard has been prepared to provide mechanisms through which various vendors of building automation, control, and building management systems may exchange information in a standardised way. It defines communication capabilities. This European Standard will be used by all involved in design, manufacture, engineering, installation and commissioning activities. SIST EN 14908-2:2014



EN 14908-2:2014 (E) 5 1 Scope This European Standard specifies the control network protocol (CNP) free-topology twisted-pair channel for networked control systems in commercial Building Automation, Controls and Building Management and is used in conjunction with EN 14908-1:2014. The channel supports communication at 78,125 kbit/s between multiple nodes, each of which consists of a transceiver, a protocol processor, an application processor, a power supply, and application electronics. This European Standard covers the complete physical layer (OSI Layer 1), including the interface to the Media Access Control (MAC) sub-layer and the interface to the medium. Parameters that are controlled by other layers but control the operation of the physical layer are also specified. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 14908-1:2014, Open Data Communication in Building Automation, Controls and Building Management - Control Network Protocol - Part 1: Protocol Stack EN 50173-1, Information technology — Generic cabling systems— Part 1: General requirements 3 Network overview The CNP free-topology twisted-pair channel supports up to 128 nodes on a single network segment with an optional link power source that supplies DC power to the nodes on the network. The channel is specified to support free-topology wiring, and will accommodate bus, star, loop, or any combination of these topologies. The total network length and number of nodes may be extended by use of CNP channel physical layer repeaters, or CNP compliant routers. The channel data rate is 78,125 kbit/s. Nodes can be either locally powered or link powered. A link-powered node derives its power from the network. The power is delivered on the same two conductors that carry data. Nodes are polarity-insensitive with respect to data as well as DC power. A locally powered node derives its power from a local source. The data is transmitted using Differential Manchester encoding, which is polarity-insensitive. 4 System specifications 4.1 General aspects This sub-clause specifies the cable type used, terminations required with bus or free topology, maximum node counts and distances for link and locally powered schemes, and the maximum steady state power that can be drawn from the link power supply. 4.2 Cable The cable shall conform to EN 50173-1. 4.3 Topology 4.3.1 Free or bus topology The network may use either a singly-terminated free topology or a doubly-terminated bus topology. SIST EN 14908-2:2014



EN 14908-2:2014 (E) 6 4.3.2 Repeater Two network segments may be interconnected with a channel physical layer repeater. No more than one physical layer repeater shall be in a path between any two nodes on a network. Physical layer repeaters shall not be interconnected in such a way as to create a loop. Each port of a physical layer repeater shall meet the specifications stated in 6.2, 6.3.3, and 6.4. The delay through the repeater shall not exceed 36 µs. 4.4 Cable termination 4.4.1 Free-topology segment A free-topology segment shall have a single termination. If the segment is locally powered, an RC network as shown in Figure 1 shall be used, with R1 = 52,3
± 1 %, 1/8 W. The termination may be located anywhere on the segment. If the segment is link-powered, the termination shall be provided by the link power source. See Figure 5. The link power source and termination may be located anywhere on the segment. 4.4.2 Bus topology segment A bus topology segment shall have two terminations, one at each end of the bus. If the segment is locally powered, an RC network as shown in Figure 1 shall be used, with R1 = 105
± 1 %, 1/8 W at each end. If the segment is link-powered, the link power source shall provide one termination. See Figure 5. The other termination shall be an RC network as shown in Figure 1, with R1 = 105
1 %, 1/8 W.
Key 1 network connection Figure 1 — Terminatio
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