1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 11783-2:2012Tractors and machinery foragriculture and forestry Serial control andcommunications data networkPart 2: Physical layerIncorporating corrigendum November 2012BS
2、 ISO 11783-2:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 11783-2:2012, The UK participation in its preparation was entrusted to Technical Committee AGE/6, Agricultural tractors and forestry machinery. A list of organizations represented on this committ
3、ee 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 2013.Published by BSI Standards Limited 2013 ISBN 978 0 580 81328 3 ICS 35.100.
4、10; 35.240.99; 65.060.01 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 31 March 2012. Amendments/corrigenda issued since publicationDate Text affectedincorpora
5、ting corrigendum November 2012. It supersedesBS ISO 11783-2:2002, which is withdrawn.30 April 2013 Implementation of ISO corrigendumNovember 2012: Tables 1 and 3 updatedReference numberISO 11783-2:2012(E)ISO 2012INTERNATIONAL STANDARD ISO11783-2Second edition2012-03-01Tractors and machinery for agri
6、culture and forestry Serial control and communications data network Part 2: Physical layer Tracteurs et matriels agricoles et forestiers Rseaux de commande et de communication de donnes en srie Partie 2: Couche physique COPYRIGHT PROTECTED DOCUMENT ISO 2012 All rights reserved. Unless otherwise spec
7、ified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office C
8、ase postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2012 All rights reservedBS ISO 11783-2:2012 ISO 11783-2:2012 (E) ISO 2012 All rights reserved iiiContents Page Foreword . vIntroduction vi1 Scope 12 N
9、ormative references 13 Terms and definitions . 14 General description . 14.1 Network physical layer 14.2 Physical media . 14.3 Differential voltage 24.4 Bus 24.4.1 Levels 24.4.2 Voltage range . 24.4.3 Termination 24.5 Resistance and capacitance 34.5.1 Internal resistance (Rin), capacitance (Cin) . 3
10、4.5.2 Differential internal resistance (Rdiff), capacitance (Cdiff) . 44.6 Bit time 54.7 AC parameters . 55 Functional description 66 Electrical specifications 76.1 Electrical data 76.1.1 General . 76.1.2 Absolute maximum ratings 76.1.3 DC parameters . 76.1.4 Bus voltages (operational) . 96.1.5 Elec
11、trostatic discharge (ESD) 96.2 Physical media parameters 96.2.1 Twisted quad cable . 96.2.2 Topology 106.2.3 ECU connection to TBC_PWR and TBC_RTN 116.2.4 Power For TBC_PWR and TBC_RTN . 116.3 TBC parameters . 126.4 Connectors . 136.4.1 General . 136.4.2 Bus extension connector 146.4.3 Implement bus
12、 breakaway connector . 166.4.4 In-cab connector 216.4.5 Diagnostic connector 247 Conformance tests 297.1 General requirements . 297.2 Internal resistance . 297.3 Internal differential resistance . 307.4 ECU recessive input threshold 307.5 ECU dominant input threshold 317.6 ECU dominant output 317.7
13、ECU internal delay time 328 Bus failure and fault confinement . 338.1 General . 33BS ISO 11783-2:2012 ISO 11783-2:2012 (E)iv ISO 2012 All rights reserved8.2 Loss of network connection .338.3 Node power or ground loss 338.4 Open and short failures 33Annex A (informative) Protocol controller timing an
14、d naming .37Annex B (informative) Examples of physical layer circuits 41Bibliography 50BS ISO 11783-2:2012 ISO 11783-2:2012 (E) ISO 2012 All rights reserved vForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies).
15、The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-g
16、overnmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2
17、. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a
18、vote. ISO 11783-2 was prepared by Technical Committee ISO/TC 23, Tractors and machinery for agriculture and forestry, Subcommittee SC 19, Agricultural electronics. This second edition cancels and replaces the first edition (ISO 11783-2:2002), which has been technically revised. It also incorporates
19、the Amendment ISO 11783-2:2002/Amd.1:2006 and the Technical Corrigendum ISO 11783-2:2002/Cor.1:2003. ISO 11783 consists of the following parts, under the general title Tractors and machinery for agriculture and forestry Serial control and communications data network: Part 1: General standard for mob
20、ile data communication Part 2: Physical layer Part 3: Data link layer Part 4: Network layer Part 5: Network management Part 6: Virtual terminal Part 7: Implement messages application layer Part 8: Power train messages Part 9: Tractor ECU Part 10: Task controller and management information system dat
21、a interchange Part 11: Mobile data element dictionary Part 12: Diagnostics services Part 13: File server Part 14: Sequence control BS ISO 11783-2:2012 ISO 11783-2:2012 (E)vi ISO 2012 All rights reservedIntroduction Parts 1 to 14 of ISO 11783 specify a communications system for agricultural equipment
22、 based on ISO 11898-14and ISO 11898-25. SAE J19398documents, on which parts of ISO 11783 are based, were developed jointly for use in truck and bus applications and for construction and agriculture applications. Joint documents were completed to allow electronic units that meet the truck and bus SAE
23、 J1939 specifications to be used by agricultural and forestry equipment with minimal changes. General information on ISO 11783 is to be found in ISO 11783-1. The purpose of ISO 11783 is to provide an open, interconnected system for on-board electronic systems. It is intended to enable electronic con
24、trol units (ECUs) to communicate with each other, providing a standardized system. The International Organization for Standardization (ISO) draws attention to the fact that it is claimed that compliance with this part of ISO 11783 may involve the use of a patent concerning the controller area networ
25、k (CAN) protocol referred to throughout the document. ISO takes no position concerning the evidence, validity and scope of this patent. The holder of this patent has assured ISO that he is willing to negotiate licences under reasonable and non-discriminatory terms and conditions with applicants thro
26、ughout the world. In this respect, the statement of the holder of this patent right is registered with ISO. Information may be obtained from: Robert Bosch GmbH Wernerstrasse 51 Postfach 30 02 20 D-70442 Stuttgart-Feuerbach Germany Attention is drawn to the possibility that some of the elements of th
27、is part of ISO 11783 may be the subject of patent rights other than those identified above. ISO shall not be held responsible for identifying any or all such patent rights. BS ISO 11783-2:2012 ISO 11783-2:2012 (E)BS ISO 11783-2:2012INTERNATIONAL STANDARD ISO 11783-2:2012(E) ISO 2012 All rights reser
28、ved 1Tractors and machinery for agriculture and forestry Serial control and communications data network Part 2: Physical layer 1 Scope ISO 11783 as a whole specifies a serial data network for control and communications on forestry or agricultural tractors and mounted, semi-mounted, towed or self-pro
29、pelled implements. Its purpose is to standardize the method and format of transfer of data between sensors, actuators, control elements and information storage and display units, whether mounted on, or part of, the tractor or implement, and to provide an open interconnect system for electronic syste
30、ms used by agricultural and forestry equipment. This part of ISO 11783 defines and describes the networks 250 kbit/s, twisted, non-shielded, quad-cable physical layer. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated referenc
31、es, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 1724, Road vehicles Connectors for the electrical connection of towing and towed vehicles 7-pole connector type 12 N (normal) for vehicles with 12 V nomin
32、al supply voltage ISO 11783-1, Tractors and machinery for agriculture and forestry Serial control and communications data network Part 1: General standard for mobile data communication 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 11783-1 apply. 4
33、General description 4.1 Network physical layer The physical layer of a network is the realization of the electrical connection of a number of electronic control units (ECUs) to a bus segment of the network. The total number of ECUs connected is limited by the electrical loads on the bus segment. In
34、accordance with the electrical parameters specified by this part of ISO 11783, the limit shall be 30 ECUs per segment. 4.2 Physical media This part of ISO 11783 defines a physical media of twisted quad cable. Two of the conductors, designated CAN_H and CAN_L, are driven with the communications signa
35、ls. The names of the ECU pins corresponding to these conductors are also designated CAN_H and CAN_L. The third and fourth conductors, designated TBC_PWR and TBC_RTN, provide power for the terminating bias circuits (TBCs) on the bus segments. 2 ISO 2012 All rights reserved4.3 Differential voltage The
36、 voltages of CAN_H and CAN_L relative to the ECU_GND (ground) of each ECU are denoted by VCAN_Hand VCAN_L. The differential voltage, Vdiff, between VCAN_Hand VCAN_Lis defined by Equation (1): Vdiff VCAN_H VCAN_L(1) 4.4 Bus 4.4.1 Levels 4.4.1.1 General The bus signal lines can be at one of two levels
37、, and in one or the other of the two logical states, recessive or dominant (see Figure 1). In the recessive state, VCAN_Hand VCAN_Lare fixed at a bias voltage level. Vdiffis approximately zero on a terminated bus. The recessive state is transmitted during bus idle when all the node CAN drivers are o
38、ff. The dominant state is transmitted when any of the node CAN drivers is on. The dominate state is represented by a differential voltage greater than a minimum threshold detected by the node CAN receiver circuits. The dominant state overwrites the recessive state and is transmitted when there is a
39、dominant bit (see also Clause 5). Key 1 recessive 2 dominant Figure 1 Physical bit representation of recessive and dominant levels or states 4.4.1.2 During arbitration During arbitration, a recessive and a dominant bit imposed on the bus signal lines during a given bit time by two ECUs results in a
40、dominant bit. 4.4.2 Voltage range The bus voltage range is defined by the maximum and minimum acceptable voltage levels of CAN_H and CAN_L, measured with respect to the ECU_GND of each ECU, for which proper operation is guaranteed when all ECUs are connected to bus signal lines. 4.4.3 Termination Th
41、e bus signal lines of a bus segment are electrically terminated at each end by a terminating bias circuit (TBC). When a node CAN driver is on, a current, I, flow is induced that is either sunk by the CAN_H termination or sourced by the CAN_L termination. This TBC shall be located externally from the
42、 ECU, in order to ensure bus bias and termination when the ECU is disconnected (see Figure 2). BS ISO 11783-2:2012 ISO 11783-2:2012 (E) ISO 2012 All rights reserved 3Key 1 ECU No. 1 2 ECU No. n 3 twisted quad cable 4 terminating bias circuit (TBC) 5 power for TBC_PWR and TBC_RTN Figure 2 Physical la
43、yer functional diagram 4.5 Resistance and capacitance 4.5.1 Internal resistance (Rin), capacitance (Cin) The internal resistance, Rin, of an ECU is defined as the resistance between CAN_H or CAN_L and ground (ECU_GND) in the recessive state, with the ECU disconnected from the bus signal line. The me
44、asurement shall be made with the ECU both powered and unpowered, and the minimum value used to confirm compliance. The internal capacitance, Cin, of an ECU is defined as the capacitance between CAN_H or CAN_L and ECU_GND during the recessive state, with the ECU disconnected from the bus signal line.
45、 The measurement shall be made with the ECU both powered and unpowered, and the minimum value used to confirm compliance. BS ISO 11783-2:2012 ISO 11783-2:2012 (E)4 ISO 2012 All rights reservedECU internal resistance and capacitance are illustrated by Figure 3. Key 1 ECU Figure 3 Internal resistance
46、and capacitance of ECU in recessive state 4.5.2 Differential internal resistance (Rdiff), capacitance (Cdiff) The differential internal resistance, Rdiff, is defined as the resistance seen between CAN_H and CAN_L in the recessive state, with the ECU disconnected from the bus signal line. The measure
47、ment shall be made with the ECU both powered and unpowered, and the minimum value used to confirm compliance. The differential internal capacitance, Cdiff, of an ECU is defined as the capacitance seen between CAN_H and CAN_L during the recessive state, with the ECU disconnected from the bus signal l
48、ines (see Figure 4). The measurement shall be made with the ECU both powered and unpowered, and the minimum value used to confirm compliance. ECU differential internal resistance and capacitance are illustrated by Figure 4. Key 1 ECU Figure 4 Differential internal resistance and capacitance of ECU i
49、n recessive state BS ISO 11783-2:2012 ISO 11783-2:2012 (E) ISO 2012 All rights reserved 54.6 Bit time The bit time, tB, is defined as the duration of one bit. Bus management functions executed within this duration, such as protocol controller synchronization, network transmission delay compensation and sample point positioning, are defined by the programmable bit timing logic of the CAN protocol-controller integrated circuit (IC). Bit time conforming to this part of ISO 11783
