BS EN 16603-50-53:2015 BSI Standards Publication Space engineering — SpaceWire — CCSDS packet transfer protocol BS EN 16603-50-53:2015 BRITISH STANDARD National foreword This British Standard is the UK implementation of EN 16603-50-53:2015 The UK participation in its preparation was entrusted to Technical Committee ACE/68, Space systems and operations A list of organizations represented on this committee can be obtained on request to its secretary This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application © The British Standards Institution 2015 Published by BSI Standards Limited 2015 ISBN 978 580 86757 ICS 33.040.40; 49.140 Compliance with a British Standard cannot confer immunity from legal obligations This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 February 2015 Amendments issued since publication Date Text affected BS EN 16603-50-53:2015 EN 16603-50-53 EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM January 2015 ICS 33.040.40; 49.140 English version Space engineering - SpaceWire - CCSDS packet transfer protocol Ingénierie spatiale - SpaceWire - protocole de transfert de paquets CCSDS Raumfahrtproduktsicherung - SpaceWire - Protokoll zur CCSDS-Paketübertragung This European Standard was approved by CEN on 23 November 2014 CEN and CENELEC 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 and CENELEC 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 and CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions CEN and CENELEC members are the national standards bodies and national electrotechnical committees 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 CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels © 2015 CEN/CENELEC All rights of exploitation in any form and by any means reserved worldwide for CEN national Members and for CENELEC Members Ref No EN 16603-50-53:2015 E BS EN 16603-50-53:2015 EN 16603-50-53:2015 (E) Table of contents Foreword Scope Normative references Terms, definitions and abbreviated terms 3.1 Terms defined in other standards .7 3.2 Terms specific to the present standard .7 3.3 Abbreviated terms 3.4 Conventions Principles 4.1 Purpose 4.2 Protocol features 4.3 Services 4.4 Guide to this document 10 Requirements 11 5.1 5.2 5.3 Service parameters .11 5.1.1 CCSDS packet 11 5.1.2 Packet length 11 5.1.3 Status code .11 5.1.4 Target SpaceWire Address 11 5.1.5 Target Logical Address 12 5.1.6 User Application Value 12 Service primitives 12 5.2.1 CCSDS Packet Transfer Service 12 5.2.2 CCSDS_PACKET_SEND.request 12 5.2.3 CCSDS_PACKET_RECEIVED.indication 13 CCSDS Packet Transfer Protocol fields 14 5.3.1 Target SpaceWire Address field 14 5.3.2 Target Logical Address field 14 5.3.3 Protocol Identifier field .14 BS EN 16603-50-53:2015 EN 16603-50-53:2015 (E) 5.3.4 Reserved field 14 5.3.5 User Application field 14 5.3.6 Packet field .15 5.4 CCSDS Packet Transfer Protocol format 15 5.5 CCSDS Packet Transfer Protocol Action 16 5.5.1 Overview 16 5.5.2 Send request 16 5.5.3 Transfer packet 17 5.5.4 Receive indication .17 Annex A (informative) Managed parameters 19 Bibliography 20 Figures Figure 4-1: Protocol configuration Figure 5-1: Encapsulated CCSDS Packet format 15 Figure 5-2: CCSDS Packet Transfer Protocol Packet Transfer 16 BS EN 16603-50-53:2015 EN 16603-50-53:2015 (E) Foreword This document (EN 16603-50-53:2015) has been prepared by Technical Committee CEN/CLC/TC “Space”, the secretariat of which is held by DIN This standard (EN 16603-50-53:2015) originates from ECSS-E-ST-50-53C 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 July 2015, and conflicting national standards shall be withdrawn at the latest by July 2015 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 has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association This document has been developed to cover specifically space systems and has therefore precedence over any EN covering the same scope but with a wider domain of applicability (e.g : aerospace) 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 BS EN 16603-50-53:2015 EN 16603-50-53:2015 (E) Scope There is a number of communication protocols that can be used in conjunction with the SpaceWire Standard (ECSS-E-ST-50-12), to provide a comprehensive set of services for onboard user applications To distinguish between the various protocols a protocol identifier is used, as specified in ECSS-E-ST-50-51 This Standard specifies the CCSDS packet transfer protocol, which is one of these protocols that works over SpaceWire The aim of the CCSDS Packet Transfer Protocol is to transfer CCSDS Packets across a SpaceWire network It does this by encapsulating the CCSDS Packet in a SpaceWire packet, transferring it across the SpaceWire network and then extracting the CCSDS Packet at the target This standard may be tailored for the specific characteristic and constrains of a space project in conformance with ECSS-S-ST-00 BS EN 16603-50-53:2015 EN 16603-50-53:2015 (E) Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this ECSS Standard For dated references, subsequent amendments to, or revision of any of these publications not apply However, parties to agreements based on this ECSS Standard are encouraged to investigate the possibility of applying the more recent editions of the normative documents indicated below For undated references, the latest edition of the publication referred to applies EN reference Reference in text Title EN 16601-00-01 ECSS-S-ST-00-01 ECSS system - Glossary of terms EN 16603-50-12 ECSS-E-ST-50-12 Space engineering - SpaceWire - Links, nodes, routers and networks EN 16603-50-51 ECSS-E-ST-50-51 Space engineering - SpaceWire protocol identification CCSDS 133.0-B-1 Space Packet Protocol, Blue Book BS EN 16603-50-53:2015 EN 16603-50-53:2015 (E) Terms, definitions and abbreviated terms 3.1 Terms defined in other standards For the purpose of this Standard, the terms and definitions from ECSS-S-ST-00-01 and ECSS-E-ST-50-51 apply 3.2 Terms specific to the present standard None 3.3 Abbreviated terms The following abbreviations are defined and used within this standard: 3.4 Abbreviation Meaning CCSDS Consultative Committee for Space Data Systems EEP error end of packet EOP end of packet SpW SpaceWire Conventions In this document hexadecimal numbers are written with the prefix 0x, for example 0x34 and 0xDF15 Binary numbers are written with the prefix 0b, for example 0b01001100 and 0b01 Decimal numbers have no prefix BS EN 16603-50-53:2015 EN 16603-50-53:2015 (E) Principles 4.1 Purpose The CCSDS Packet Transfer Protocol has been designed to encapsulate a CCSDS Space Packet into a SpaceWire packet, transfer it from an initiator to a target across a SpaceWire network, extract it from the SpaceWire packet and pass it to a target user application This protocol does not provide any means for ensuring delivery of the packet nor is it responsible for the contents of the packet being a CCSDS Space Packet The CCSDS Space Packet Protocol is defined in the following document: CCSDS 133.0-B-1 Space Packet Protocol Blue Book Issue September 2003 or a later issue Figure 4-1 illustrates the location of the CCSDS Space Packet transfer Protocol in a typical onboard protocol stack The CCSDS Space Packet transfer Protocol provides a unidirectional data transfer service from a single source user application to a single destination user application through a SpaceWire network User Application User Application CCSDS Space packet Transfer Protocol CCSDS Space packet Transfer Protocol SpaceWire Network SpaceWire Network Figure 4-1: Protocol configuration 4.2 Protocol features The CCSDS Space Packet transfer Protocol provides the capability to transfer CCSDS Space Packets between onboard users of a SpaceWire network The CCSDS space packets may be of variable length or fixed size at the discretion of the user and may be submitted for transmission at variable intervals The BS EN 16603-50-53:2015 EN 16603-50-53:2015 (E) composition of the CCSDS space packet is under the responsibility of the user application and is not checked by the CCSDS space packet transfer protocol 4.3 Services The CCSDS Space Packet Transfer Protocol provides users with data transfer services The point at which a service is provided by a protocol entity to a user is called a Service Access Point A Service Access Point of the Space Packet Transfer Protocol is identified by a SpaceWire address and each service user is also identified by a SpaceWire Address Service data units submitted to a Service Access Point are processed in the order of submission Implementations may be required to perform flow control at a Service Access Point between the service user and the service provider However, this standard does not recommend a scheme for flow control between the user and the provider The followings features are offered by the data transfer service defined in this Standard: • Unidirectional (one way) data transfer service • Asynchronous Service There are no predefined timing rules for the transfer of service data units supplied by the service user The user may request data transfer at any time it desires, but there may be restrictions imposed by the provider on the data generation rate • Unconfirmed Service: the sending user does not receive confirmation from the receiving end that data has been received • Incomplete Services The services not guarantee completeness, nor they provide a retransmission mechanism • SDU format: the service does not check the format of the submitted CCSDS Space packet • Non sequence Preserving Service The sequence of service data units supplied by the sending user may not be preserved through the underlying network The end-to-end quality-of-service provided to service users is the one that is provided by the underlying SpaceWire network The Space Packet Transfer Protocol does not provide any mechanisms for guaranteeing a particular quality-of-service; it is the responsibility of implementing organizations to ensure that the end-to-end performance of a particular service instance meets the requirements of its users Sequence preservation of packets in a SpaceWire network is dependent on the underlying network topology and configuration Topologies and configurations which allow only a single route from the source to the destination, i.e configurations that are not using group adaptive routing, are sequence preserving BS EN 16603-50-53:2015 EN 16603-50-53:2015 (E) 4.4 Guide to this document Clause presents the purpose, protocol features and an overview of the services the CCSDS packet transfer protocol offers Clause 5.1 defines the service parameters Clause 5.2 specifies the service primitives provided by the protocol Clause 5.3 defines the protocol fields used in the CCSDS packet transfer protocol packets Clause 5.4 specifies the format of the packets used by the CCSDS packet transfer protocol Clause 5.5 specified the action of the CCSDS packet transfer protocol Annex A lists the managed parameters associated with this protocol 10 BS EN 16603-50-53:2015 EN 16603-50-53:2015 (E) Requirements 5.1 Service parameters 5.1.1 a CCSDS packet The CCSDS packet parameter, intended as the service data unit transferred by the CCSDS packet transfer service, shall be the CCSDS Space Packet as defined in CCSDS 133.0-B-1 Space Packet Protocol, Blue Book, Issue 1, September 2003 5.1.2 Packet length a The value of the packet length shall be equal to at least and at most 65542 octets b Individual project organizations may establish the maximum length for a particular mission NOTE 5.1.3 The length parameter defines the length of the Data Unit submitted by the user Status code a The Status code parameter shall be used to indicate the validity of the packet to the receiving service user b The Status code parameter shall take one of the following values: 0x00 indicates that the packet is ok 0x01 indicates packet arrived terminated by EEP 0x02 indicates reserved field was non-zero 5.1.4 a Target SpaceWire Address The Target SpaceWire Address parameter shall be used to define the path to the Target when SpaceWire path addressing is being used 11 BS EN 16603-50-53:2015 EN 16603-50-53:2015 (E) 5.1.5 a The Target Logical Address parameter shall be used to define the logical address of the Target that is to receive the CCSDS packet 5.1.6 a Target Logical Address User Application Value The User Application Value shall be an 8-bit value which is transferred along with the CCSDS packet to the Target NOTE 5.2 Service primitives 5.2.1 a CCSDS Packet Transfer Service The service primitives associated with this service shall be the following CCSDS_PACKET_SEND.request, CCSDS_PACKET_RECEIVE.indication 5.2.2 CCSDS_PACKET_SEND.request 5.2.2.1 Function a At the initiator, the CCSDS Packet Transfer service user shall pass a CCSDS_PACKET_SEND.request primitive to the service provider to request that a CCSDS Packet is transferred to the user at the target across the SpaceWire network 5.2.2.2 a 5.2.2.3 a CCSDS_PACKET_SEND.request (CCSDS Packet, Packet Length, Target SpaceWire Address, Target Logical Address, User Application Value) When Generated The CCSDS_PACKET_SEND.request primitive shall be passed to the service provider to request it to send the CCSDS Packet 5.2.2.4 a Semantics The CCSDS_PACKET.request primitive shall provide the following parameters: 12 Its value and use is user specific Effect On Receipt Receipt of the CCSDS_PACKET_SEND.request primitive shall cause the service provider to transfer the CCSDS Packet BS EN 16603-50-53:2015 EN 16603-50-53:2015 (E) 5.2.2.5 a Additional Comments The CCSDS_PACKET_SEND.request primitive shall be used to transfer CCSDS Packets across the SpaceWire network along the route defined by the Target SpaceWire Address and Target Logical Address parameters 5.2.3 CCSDS_PACKET_RECEIVED.indication 5.2.3.1 Function a At the target, the service provider shall pass a CCSDS_PACKET_RECEIVED.indication to the CCSDS Packet Service user to deliver a Packet 5.2.3.2 a Semantics The CCSDS_PACKET_RECEIVED.indication primitive shall provide parameters as follows: CCSDS_PACKET_RECEIVED.indication (CCSDS Packet, User Application Value, Status) b If the packet arrived is terminated by EEP or the Reserved field is nonzero the CCSDS Packet and the User Application Value shall be null c The Status parameter shall be one of the following codes: 0x00 indicates that the packet arrived with no known error, 0x01 indicates that the packet arrived terminated by EEP, 0x02 indicates that the Reserved field was non-zero 5.2.3.3 a The CCSDS_PACKET_RECEIVED.indication primitive shall be passed from the service provider to the CCSDS Packet Service user at the target to deliver a CCSDS Packet 5.2.3.4 a Effect On Receipt The effect of receipt of the CCSDS_PACKET_RECEIVED.indication primitive by the CCSDS Packet Service user shall be defined by the user 5.2.3.5 a When Generated Additional Comments The CCSDS_PACKET_RECEIVED.indication primitive shall be used to deliver CCSDS Packets to the CCSDS Packet Service user at the target 13 BS EN 16603-50-53:2015 EN 16603-50-53:2015 (E) 5.3 CCSDS Packet Transfer Protocol fields 5.3.1 a Target SpaceWire Address field The Target SpaceWire Address field shall comprise zero or more data characters forming the SpaceWire address which is used to route the CCSDS Packet Transfer Protocol packet to the target NOTE b SpaceWire path addressing and regional addressing may be used c The Target SpaceWire Address field shall not be used when a single logical address is being used for routing the CCSDS Packet Transfer Protocol packet to the target NOTE 5.3.2 a In this case the CCSDS Packet Transfer Protocol packet is routed to the target by the Target Logical Address contained in the Target Logical Address field Target Logical Address field Target Logical Address field shall be an 8-bit field that contains a logical address of the target 5.3.3 NOTE The Target Logical Address field is normally set to a logical address recognised by the target NOTE If the target does not have a specific logical address then the Target Logical Address field can be set to the default value 254 (0xFE) NOTE A target can have more than one logical address Protocol Identifier field a The Protocol Identifier field shall be an 8-bit field that contains the Protocol Identifier b The Protocol Identifier field shall be set to the value (0x02) which is the Protocol Identifier for the CCSDS Packet Encapsulation Protocol 5.3.4 a a Reserved field The Reserved shall be an 8-bit field that is set to 0x00 5.3.5 User Application field The User Application field shall be an 8-bit field which is transferred along with the CCSDS packet to the Target NOTE 14 The Target SpaceWire Address is stripped off by the time the packet reaches the target Its value and use is user specific BS EN 16603-50-53:2015 EN 16603-50-53:2015 (E) NOTE 5.3.6 5.4 If for example the target supports virtual channels, the User Application field can be set to a virtual channel number Packet field a The CCSDS Packet field shall be a variable length field that contains the CCSDS Packet b The first byte of the CCSDS Packet field shall be the first byte of the CCSDS Packet c The byte order of the CCSDS Packet field shall be the same as the CCSDS Packet CCSDS Packet Transfer Protocol format 5.4.1.1 a Fields The CCSDS Packet Transfer Protocol packet shall contain the fields shown in Figure 5-1 First byte transmitted Target SpW Address … Target SpW Address Target Logical Address Protocol Identifier Reserved = 0x00 User Application CCSDS Packet (First Byte) CCSDS Packet CCSDS Packet CCSDS Packet CCSDS Packet CCSDS Packet CCSDS Packet CCSDS Packet (Last Byte) EOP Last byte transmitted Figure 5-1: Encapsulated CCSDS Packet format 5.4.1.2 a The Target SpaceWire Address field shall be as defined in clause 5.3.1 5.4.1.3 a Protocol Identifier field The Protocol Identifier field shall be as defined in clause 5.3.3 5.4.1.5 a Target Logical Address field The Target Logical Address field shall be as defined in clause 5.3.2 5.4.1.4 a Target SpaceWire Address field Reserved field The Reserved field format shall be as defined in clause 5.3.4 15 BS EN 16603-50-53:2015 EN 16603-50-53:2015 (E) 5.4.1.6 a The User Application field format shall be as defined in clause 5.3.5 5.4.1.7 a 5.5 CCSDS Packet field The CCSDS Packet field format shall be as defined in clause 5.3.6 5.4.1.8 a User Application field EOP character The end of the CCSDS Packet Transfer Protocol packet shall be indicated by an EOP character CCSDS Packet Transfer Protocol Action 5.5.1 Overview The normal sequence of actions for a CCSDS Packet Transfer Protocol packet transfer is illustrated in Figure 5-2 Target Initiator Send Request Transfer Packet Receive Indication Figure 5-2: CCSDS Packet Transfer Protocol Packet Transfer 5.5.2 16 Send request a The CCSDS Packet Transfer Protocol packet transfer shall begin when an initiator user application requests to send a CCSDS Packet Transfer Protocol packet (Send Request) b The initiator user application shall pass the following information to the initiator: Target SpaceWire Address Target Logical Address CCSDS Packet Packet Length User Application Value BS EN 16603-50-53:2015 EN 16603-50-53:2015 (E) c If the Packet Length of the CCSDS Packet is greater than the maximum acceptable length, the following shall be done: Reject the Send Request Inform the initiator user application 5.5.3 a Transfer packet In response to the send request the initiator shall encapsulate the CCSSDS Space Packet into a SpaceWire packet as described in clause 5.4 and send it across the SpaceWire network to the target (Transfer Packet) NOTE The Target SpaceWire Address and Target Logical Address are used to route the command packet to the target 5.5.4 Receive indication 5.5.4.1 Protocol identifier a When a SpaceWire packet is received at the target and the Protocol Identifier field is 0x02 the packet shall be regarded as a CCSDS Packet Transfer Protocol packet 5.5.4.2 Reserved field zero a If the CCSDS Packet Transfer Protocol packet arrives at the target with the Reserved field set to 0x00 and is terminated by an EOP, the CCSDS Packet shall be extracted from the SpaceWire packet and passed to the target user application b If the CCSDS Packet Transfer Protocol packet arrives at the target with the Reserved field set to 0x00 and is terminated by an EOP, the value of the User Application field shall be passed to the target user application 5.5.4.3 Reserved field not zero a If the CCSDS Packet Transfer Protocol packet arrives at the target with the Reserved field set to a non-zero value and is terminated by an EOP the CCSDS Packet Transfer Protocol packet shall be discarded, b If the CCSDS Packet Transfer Protocol packet arrives at the target with the Reserved field set to a non-zero value and is terminated by an EOP, the target user application should be informed that an invalid CCSDS Packet Transfer Protocol packet has been received 5.5.4.4 a Error End of Packet If the CCSDS Packet Transfer Protocol packet arrives at the target terminated by an EEP, the CCSDS Packet Transfer Protocol packet shall be discarded 17 BS EN 16603-50-53:2015 EN 16603-50-53:2015 (E) b 18 If the CCSDS Packet Transfer Protocol packet arrives at the target terminated by an EEP, the target user application should be informed that an invalid CCSDS Packet Transfer Protocol packet has been received BS EN 16603-50-53:2015 EN 16603-50-53:2015 (E) Annex A (informative) Managed parameters In order to provide an optimised implementation, some parameters associated with the CCSDS Packet Transfer service are handled by management, rather than by inline communications protocol The managed parameters are those which tend to be static for long periods of time, and whose change generally signifies a major reconfiguration of the service provider associated with a particular mission Through the use of a management system, management conveys the required information to the service provider The managed parameters used for the CCSDS Packet Transfer Service are listed in Table A-1 These parameters are defined in an abstract sense, and are not intended to imply any particular implementation of a management system The value of these parameters are defined implementation for a specific mission Table A-1: Managed parameters Managed parameter Allowed value Minimum CCSDS Space packet length (bytes) Integer Maximum CCSDS Space packet size (bytes) Integer 19 BS EN 16603-50-53:2015 EN 16603-50-53:2015 (E) Bibliography EN reference Reference in text Title EN 16601-00 ECSS-ST-S-00 ECSS system - Description, implementation and general requirements http://www.spacewire.esa.int SpaceWire website 20 This page deliberately left blank NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW British Standards Institution (BSI) BSI is the national body responsible for preparing British Standards and other standards-related publications, information and services BSI is incorporated by Royal Charter British Standards and other standardization products are published by BSI Standards Limited About us Revisions We bring together business, industry, government, consumers, innovators and others to shape their combined experience and expertise into standards -based solutions Our British Standards and other publications are updated by amendment or revision The knowledge embodied in our standards has been carefully assembled in a dependable format and refined through our open consultation process Organizations of all sizes and across all sectors choose standards to help them achieve their goals Information on standards We can provide you with the knowledge that your organization needs to succeed Find out more about British Standards by visiting our website at bsigroup.com/standards or contacting our Customer Services team or Knowledge Centre Buying standards You can buy and download PDF versions of BSI publications, including British and adopted European and international standards, through our website at bsigroup.com/shop, where hard copies can also be purchased If you need international and foreign standards from other Standards Development Organizations, hard copies can be ordered from our Customer Services team Subscriptions Our range of subscription services are designed to make using standards easier for you For further information on our subscription products go to bsigroup.com/subscriptions With British Standards Online (BSOL) you’ll have instant access to over 55,000 British and adopted European and international standards from your desktop It’s available 24/7 and is refreshed daily so you’ll always be up to date You can keep in touch with standards developments and receive substantial discounts on the purchase price of standards, both in single copy and subscription format, by becoming a BSI Subscribing Member PLUS is an updating service exclusive to BSI Subscribing Members You will automatically receive the latest hard copy of your standards when they’re revised or replaced To find out more about becoming a BSI Subscribing Member and the benefits of membership, please visit bsigroup.com/shop With a Multi-User Network Licence (MUNL) you are able to host standards publications on your intranet Licences can cover as few or as many users as you wish With updates supplied as soon as they’re available, you can be sure your documentation is current For further information, email bsmusales@bsigroup.com BSI Group Headquarters 389 Chiswick High Road London W4 4AL UK We continually improve the quality of our products and services to benefit your business If you find an inaccuracy or ambiguity within a British Standard or other BSI publication please inform the Knowledge Centre Copyright All the data, software and documentation set out in all British Standards and other BSI publications are the property of and copyrighted by BSI, or some person or entity that owns copyright in the information used (such as the international standardization bodies) and has formally licensed such information to BSI for commercial publication and use Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means – electronic, photocopying, recording or otherwise – without prior written permission from BSI Details and advice can be obtained from the Copyright & Licensing Department Useful Contacts: Customer Services Tel: +44 845 086 9001 Email (orders): orders@bsigroup.com Email (enquiries): cservices@bsigroup.com Subscriptions Tel: +44 845 086 9001 Email: subscriptions@bsigroup.com Knowledge Centre Tel: +44 20 8996 7004 Email: knowledgecentre@bsigroup.com Copyright & Licensing Tel: +44 20 8996 7070 Email: copyright@bsigroup.com