ISO/FDIS 11783-2

• Abstract:

  ISO 11783 specifies a serial data network for control and communications on forestry or agricultural tractors and mounted, semi-mounted, towed or self-propelled 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. ISO 11783 also provides an open interconnect system for on-board electronic systems used by agriculture and forestry equipment. It is intended to enable electronic control units (ECUs) to communicate with each other, providing a standardized system. This document defines and describes the network's 250 kbit/s, twisted, non-shielded, quad-cable physical layer and an alternative cable and architecture named twisted pair physical layer (TPPL) based on a 250 kbit/s, un-shielded, twisted pair cable network layer which is fully backward compatible to twisted quad based machines and devices. NOTE Where not differently specified, requirements are valid for both twisted quad and TPPL.

• Status: Not Published
• ICS: 35.240.68 - IT applications in agriculture
• ICS: 65.060.01 - Agricultural machines and equipment in general
• Technical Committee: ISO/TC 23/SC 19 - Agricultural electronics
• Drafting Committee: ISO/TC 23/SC 19/WG 5 - Communication infrastructures
• Current Stage: 5020 - FDIS ballot initiated: 2 months. Proof sent to secretariat
• Start Date: 09-Oct-2026
• Completion Date: 09-Oct-2026

• Revises: ISO 11783-2:2019 - Tractors and machinery for agriculture and forestry — Serial control and communications data network — Part 2: Physical layer
• Effective Date: 21-Sep-2024

ISO/FDIS 11783-2 is an ISO Final Draft International Standard in the ISO 11783 series for tractors and machinery for agriculture and forestry. ISO/FDIS 11783-2 specifies the physical layer of the serial control and communications data network, including the 250 kbit/s controller area network (CAN) interface, cable media, termination, connectors and conformance tests. It is intended for ECU designers, system designers, manufacturers and test labs that need compatible on-board communications hardware for agricultural and forestry equipment.

What does ISO/FDIS 11783-2 specify?

ISO/FDIS 11783-2 specifies the physical layer for serial control and communications on forestry or agricultural tractors and mounted, semi-mounted, towed or self-propelled implements. It defines how data move between sensors, actuators, control elements, and information-storage and -display units, and it also describes an open interconnect system for on-board electronic systems.

The document is organized into:

• general requirements
• network segment requirements
• electrical requirements
• a conformance test plan
• bus failure and fault confinement
• informative annexes for timing, circuit examples and an optional stub connector

Annex	What it covers
Annex A	Protocol controller timing and naming
Annex B	Examples of physical layer circuits
Annex C	Optional ECU stub connector

What are the key requirements of ISO/FDIS 11783-2?

ISO/FDIS 11783-2 sets out the physical media, electrical behavior, topology and connector rules that make ECUs from different suppliers work on the same bus. In practice, it tells designers what must be fixed in hardware and wiring so that communications stay stable, interoperable and testable.

Network layers and bit timing

ISO/FDIS 11783-2 links the physical coding sublayer to CAN requirements from ISO 11898-1 and the high-speed physical medium attachment sublayer to ISO 11898-2. The document uses a 250 kbit/s bit rate and a single-sample-point method with the sample point placed at 80 % of the bit time, so controller timing has to match that budget.

That matters because ECUs, gateways and displays must share the same timing assumptions. Annex A explains the timing names and the relationship between bit segments, arbitration and internal delay time.

Two physical media are defined

ISO/FDIS 11783-2 defines two media:

• TQPL - unshielded twisted quad cable
• TPPL - unshielded twisted pair cable

TQPL uses four conductors, with two for CAN_H and CAN_L and two for power to the terminating bias circuits. TPPL uses the CAN_H and CAN_L pair and is intended as a backward-compatible alternative to twisted quad machines and devices. For a buyer or integrator, this is the first design choice that affects harnesses, connectors and termination hardware.

Termination and network segment layout

ISO/FDIS 11783-2 requires a linear network segment with termination at both ends. For TQPL, the ends use terminating bias circuits outside the ECU housing so that the bus remains biased and terminated even if an ECU is disconnected. For TPPL, the ends use passive termination or split termination, and Type II ECUs are only to be used at one or both ends of the bus.

This is important because termination controls reflections and common-mode behavior. If the bus is built with the wrong termination style, the network may still seem to work at first but become unreliable under length, loading or EMC stress.

ECU electrical behavior and stub control

ISO/FDIS 11783-2 defines how to measure internal resistance, differential resistance, internal capacitance and differential capacitance of ECUs in the recessive state. It also defines a weak-termination option for TPPL stubs using ECU Type I WEAK, and limits how many of those ECUs may be used on one network segment.

In practice, this is about loading the bus correctly. Designers have to know whether an ECU is Type I, Type I WEAK or Type II, because that affects where it may be placed and whether it can be used as a bus end or only as a stub device.

Cable, topology and connector rules

ISO/FDIS 11783-2 gives physical media parameters for both cable types, including impedance, resistance, capacitance, twist and operating temperature range. It also limits topology: TQPL is intended to use a bus line with short stubs, while TPPL allows single stubs, compound stubs and multiple splices only within stated layout limits.

The connector rules are equally practical. The document requires an implement bus breakaway connector, an in-cab connector and a diagnostic connector, and it allows a bus extension connector and an optional ECU stub connector. The pin allocations and connector geometry matter because they determine serviceability, interchangeability and whether the network can be extended without violating the electrical model.

Power, voltages and fault tolerance

ISO/FDIS 11783-2 sets operating voltage and current expectations for the tractor supply architecture, for the implement side, and for the voltage drop through an implement. It also covers the bus-disconnected and bus-connected voltage behavior of ECUs.

The document then goes further into fault confinement. It requires the remaining nodes to keep communicating through many single-fault conditions, such as disconnection, loss of node power or ground, open lines and several short-circuit cases. For machine builders, this means the network has to keep working in realistic service faults and has to fail safe where communication integrity is lost.

Conformance testing and ESD

ISO/FDIS 11783-2 includes a conformance test plan for internal resistance, differential resistance, recessive and dominant input thresholds, internal delay time and electrostatic discharge (ESD). The ESD testing refers to ISO 10605 methods and is performed on CAN_H and CAN_L with the ECU disconnected from the bus.

That matters for verification and type testing. Manufacturers can use the test plan to check that an ECU design matches the electrical model expected by the network before the equipment goes into production.

What terms does ISO/FDIS 11783-2 define?

• ECU Type I - an electronic control unit without internal termination.
• ECU Type I WEAK - an ECU with split termination coupled to ECU_GND by a capacitor, used for stubs only.
• ECU Type II - an electronic control unit with an internal termination circuit.
• internal delay time - the sum of asynchronous delays along the ECU transmit and receive path relative to the bit timing logic.
• TPPL - a 250 kbit/s unshielded twisted pair cable-based network layer intended as an alternate to TQPL and backward compatible with it.
• TQPL - a 250 kbit/s unshielded twisted quad cable-based network layer.
• network segment - a single CAN network using a linear topology with stubs.
• node - a device linked to the network and capable of communicating according to the protocol.

Who uses ISO/FDIS 11783-2?

ISO/FDIS 11783-2 is used by tractor and implement OEMs, ECU designers, harness engineers, connector engineers and system integrators in agriculture and forestry. It is also used by test laboratories and compliance teams that need to verify electrical compatibility, timing, termination and fault behavior.

In practice, these users rely on the document when they:

• choose between TQPL and TPPL
• design network wiring and stub lengths
• assign connector pins and cable colors
• verify termination and bias circuits
• test ECUs for voltage, timing and ESD behavior
• check that a machine continues communication under fault conditions

What changed in ISO/FDIS 11783-2 from the previous edition?

ISO/FDIS 11783-2 is the fourth edition and it cancels and replaces ISO 11783-2:2019. It also incorporates ISO 11783-2:2012/Cor 1:2012.

The main changes stated for this edition are:

• separation of requirements for ECU designers and for system designers
• updating of electrical requirements to the current state of the art
• alignment of the document to ISO/IEC directives
• restructuring and rationalization of the document

Which standards are used with ISO/FDIS 11783-2?

ISO/FDIS 11783-2 refers to these normative and companion standards:

• ISO 11783-1 - provides the general standard for mobile data communication and the shared terms used by this part.
• ISO 11898-1 - supplies the CAN data link layer and physical coding sublayer requirements used by the network.
• ISO 11898-2 - supplies the high-speed physical medium attachment requirements used by the physical interface.
• ISO 1724 - provides the towing-vehicle electrical connector context used for the tractor receptacle arrangement.
• SAE J1939-11 - provides the twisted shielded pair physical layer reference.
• SAE J1939-13 - provides the off-board diagnostic connector reference.
• SAE J1939-15 - provides the unshielded twisted pair physical layer reference used for TPPL.

What does the ISO/FDIS 11783-2 document contain?

ISO/FDIS 11783-2 contains electrical parameter tables, topology limits, connector pin allocations, test setups and fault-case descriptions. It also includes figures for the functional network layout, the two cable architectures, termination circuits, breakaway connectors, in-cab and diagnostic connectors, and the optional stub connector.

The annexes add practical implementation material rather than new normative requirements. Annex A explains bit timing terms, Annex B shows example physical-layer circuits and interconnections, and Annex C shows the optional ECU stub connector.

For design and testing teams, the value of the document is that it turns the ISO 11783 network into a concrete wiring and interface specification. For certification or audit work, it shows what to measure, where to measure it and how the network should behave when ECUs are connected, disconnected or exposed to faults.

FINAL DRAFT
International
Standard
ISO/TC 23/SC 19
Tractors and machinery for
Secretariat: DIN
agriculture and forestry — Serial
Voting begins on:
control and communications data
2026-10-09
network —
Voting terminates on:
2026-12-04
Part 2:
Physical layer
Tracteurs et matériels agricoles et forestiers — Réseaux de
commande et de communication de données en série —
Partie 2: Couche physique
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
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INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
FINAL DRAFT
International
Standard
ISO/TC 23/SC 19
Tractors and machinery for
Secretariat: DIN
agriculture and forestry — Serial
Voting begins on:
control and communications data
network —
Voting terminates on:
Part 2:
Physical layer
Tracteurs et matériels agricoles et forestiers — Réseaux de
commande et de communication de données en série —
Partie 2: Couche physique
© ISO 2026
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ii
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 2
5 General requirements . 3
5.1 Network physical layer .3
5.2 Physical media .3
5.3 Termination circuit .3
5.3.1 Twisted quad network segment .3
5.3.2 Twisted pair physical layer network segment .4
5.4 Resistance and capacitance .6
5.4.1 Internal resistance (R ), internal capacitance (C ) .6
in in
5.4.2 Differential internal resistance (R ), differential internal capacitance (C ) .6
diff diff
5.4.3 Weak termination for stubs .7
5.5 Bit time requirements .7
5.6 AC parameters.7
6 Network segment requirements . 8
6.1 Twisted quad network segment .8
6.2 TPPL network segment .8
7 Electrical requirements . 8
7.1 Electrical operating ranges .8
7.1.1 General requirements .8
7.1.2 ECU DC voltages .8
7.1.3 Power supply DC parameters .9
7.1.4 Bus voltages (operational) . 12
7.2 Physical media parameters . 12
7.2.1 Unshielded twisted quad cable . . 12
7.2.2 Unshielded twisted pair . 12
7.3 Topology of twisted quad physical layers . 13
7.3.1 General . 13
7.3.2 ECU connection to TBC_PWR and TBC_RTN .14
7.3.3 Power for TBC_PWR and TBC_RTN . 15
7.4 Topology of twisted pair physical layer . 15
7.4.1 General specifications . 15
7.4.2 Single stub . 15
7.4.3 Compound stub . 15
7.4.4 Multiple splice .16
7.5 TBC parameters .17
7.6 Termination circuit parameters .18
7.7 Connectors .19
7.7.1 General .19
7.7.2 Bus extension connector . 20
7.7.3 Implement bus breakaway connector . 22
7.7.4 In-cab connector . 30
7.7.5 Diagnostic connector . 38
8 Conformance test plan .43
8.1 General requirements .43
8.2 Internal resistance . 44
8.3 Internal differential resistance . 44
8.4 ECU recessive input threshold .45

iii
8.5 ECU dominant input threshold . 46
8.6 ECU internal delay time . 46
8.7 Electrostatic discharge (ESD) .47
9 Bus failure and fault confinement .48
9.1 General . 48
9.2 Loss of network connection . 48
9.3 Node power or ground loss. 48
9.4 Reaction to power-supply voltage disturbances . 48
9.5 Network disruption during connection, disconnection or power-up . 48
9.6 Open and short failures . 49
Annex A (informative) Protocol controller timing and naming .52
Annex B (informative) Examples of physical layer circuits .55
Annex C (informative) Optional ECU stub connector . 61
Bibliography .63

iv
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). 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-governmental, 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.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 23, Tractors and machinery for agriculture and
forestry, Subcommittee SC 19, Agricultural electronics.
This fourth edition cancels and replaces the third edition (ISO 11783-2:2019), which has been technically
revised.
The main changes are as follows:
— separation of requirements for ECU designers and for system designers;
— updating of electrical requirements to the current state of the art;
— restructuring and rationalization of the document.
A list of all the parts in the ISO 11783 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

v
Introduction
The ISO 11783 series specifies a communications system for agricultural equipment based on the ISO 11898-1
CAN protocol. The SAE J1939 series1), on which parts of ISO 11783 series are based, were developed jointly
for use in truck and bus, construction, and agriculture applications. Joint documents have been completed
to allow electronic units that meet the truck and bus SAE J1939 specifications to be used by agricultural
and forestry equipment with minimal changes. General information on the ISO 11783 series can be found in
ISO 11783-1.
The purpose of the ISO 11783 series is to provide an open, interconnected system for on-board electronic
systems. It is intended to enable electronic control units (ECUs) to communicate with each other, providing
a standardized system.
vi
FINAL DRAFT International Standard ISO/FDIS 11783-2:2026(en)
Tractors and machinery for agriculture and forestry — Serial
control and communications data network —
Part 2:
Physical layer
IMPORTANT — This document contains colours which are considered to be useful for the correct
understanding of the document. Users should therefore consider printing this document using a
colour printer.
1 Scope
This document specifies the device interface using the CAN HS (high-speed) physical medium attachment
(PMA) sublayer, as given in ISO 11898-2, and the physical coding sublayer (PCS), as given in ISO 11898-1. It
specifies two physical medium-dependent sublayers:
a) un-shielded, twisted-quad cable, and
b) un-shielded, twisted-pair cable.
NOTE Where not otherwise specified, requirements are valid for both twisted quad physical layer (TQPL) and
twisted pair physical layer (TPPL).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, 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 nominal 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
ISO 11898-1:2024, Road vehicles — Controller area network (CAN) — Part 1: Data link layer and physical coding
sublayer
ISO 11898-2:2026, Road vehicles — Controller area network (CAN) — Part 1: High-speed physical medium
attachment (PMA) sublayer
S A E J1939 -15: 2018 , Physical Layer, 250 Kbps, Un-Shielded Twisted Pair (UTP)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11783-1 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/

3.1
ECU Type I
electronic control unit without internal termination
3.2
ECU Type I WEAK
electronic control unit with split termination coupled to ECU_GND with a capacitor and that is used for stubs
only (see 5.4.3)
3.3
ECU Type II
electronic control unit with a internal termination circuit
3.4
internal delay time
the sum of all asynchronous delays that occur along the transmission and reception path within the ECU,
relative to the bit timing logic unit of the CAN implementation (see A.2)
3.5
twisted pair physical layer
TPPL
250 kbit/s, unshielded, twisted pair cable-based network layer intended to be used as an alternate to the
twisted quad physical layer and that is backward compatible with machines based on a twisted quad
physical layer
3.6
machine
forestry or agricultural tractor or mounted, semi-mounted, towed or self-propelled implement
3.7
network segment
single CAN network using a linear topology configuration with stubs
3.8
node
assembly, linked to a communication network, capable of communicating across the network according to a
communication protocol specification
Note 1 to entry: A node can be in one of four states: integrating, idle, receiver or transmitter.
Note 2 to entry: A node operating in a controller area network (CAN) is called a CAN node.
[SOURCE: ISO 11898-1:2024, 3.39, modified — definition has been modified to exclude further information.]
3.9
twisted quad physical layer
TQPL
250 kbit/s, unshielded, twisted quad cable-based network layer
4 Abbreviated terms
IBBC Implement Bus Breakaway Connector (socket)
IBBP Implement Bus Breakaway Plug
CAN controller area network
PMA physical medium attachment
PCS physical Coding Sublayer
ECU Electronic Control Unit
PWR power
GND ground
DC direct current
MDI medium dependent interface
AC alternating Current
TBC Terminating Bias Circuit
TBC_GND Terminating Bias Circuit Ground
TBC_RTN Terminating Bias Circuit Return
5 General requirements
5.1 Network physical layer
The physical coding sublayer shall be in accordance with CAN CC requirements as given in ISO 11898-1:2024,
Clause 7; it is implemented in CAN protocol controller units using a non-return-to-zero (NRZ) coding. The
physical medium attachment (PMA) sublayer shall be in accordance with the requirements for high-speed
PMA entities supporting bit rates up to 1 Mbit/s as given in ISO 11898-2:2026, Table 15 in particular); it is
implemented in so-called high-speed (HS) CAN transceiver units.
The physical medium-dependent (PMD) sublayer is specified in the following subclauses. This includes
requirements for the ECU designer: 5.4, 5.5, 7.1.2, 7.1.3.5, 7.1.3.5.
The requirements for network designers are given in: 5.2, 5.3, Clause 6, 7.1.3.1, 7.1.3.2, 7.1.3.3, 7.1.3.4, 7.1.4,
7.2, 7.3, 7.4, 7.5, 7.6, 7.7.
5.2 Physical media
This document defines two types of physical media.
a) TQPL: shall be composed by four conductors, two of them, designated CAN_H and CAN_L, are driven
with the electrical communication signals. The names of the ECU connector 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 network segment.
b) TPPL: shall be composed by a twisted pair cable as described in SAE J1939-15. The conductors,
designated CAN_H and CAN_L, are driven with the MDI as specified in ISO 11898-2. The names of the
ECU connector pins corresponding to these conductors are also designated CAN_H and CAN_L.
5.3 Termination circuit
5.3.1 Twisted quad network segment
The bus signal lines of a twisted quad network segment shall be electrically terminated at each end by a
terminating bias circuit. When a node transceiver is on, a current (I) flow is induced that is either sunk by
the CAN_H termination or is sourced by the CAN_L termination. This TBC shall be located outside the ECU
housing, to ensure bus bias and termination when the ECU is disconnected (see Figure 1).

Key
1 ECU no. 1
2 ECU no. n
3 terminating bias circuit (TBC)
4 power for TBC_PWR and TBC_RTN
5 twisted quad cable
Figure 1 — Physical layer functional diagram
5.3.2 Twisted pair physical layer network segment
The bus signal lines of a TPPL network segment shall be electrically terminated at each end using a
terminating resistor R (see Figure 2) or with a passive split termination circuit using two resistors R
t tCAN_H
and R coupled to ground by a capacitor C (see Figure 4). 7.6 defines electrical requirements for the
tCAN_L split
two alternatives.
Figure 3 shows the termination for a network segment, using Type II ECUs.
The system designer should take care that the network segment is terminated at one or both ends. Type II
ECUs shall be marked. A Type II ECU shall only be used at one or both ends of a bus, even when the machine
is attached to another machine by an IBBC. Type II ECUs shall only be powered by ECU_PWR/ECU_GND.

Key
1 ECU Type I No. 1
2 ECU Type I No. n
3 unshielded twisted pair
4 terminating resistors R
t
Figure 2 — TPPL passive termination circuit by using single resistors at each end of the network
segment
Key
1 ECU Type I
2 ECU Type II with internal R
t
3 unshielded twisted pair
Figure 3 — TPPL passive termination circuit (one side) by using an ECU Type II as a termination
Key
1 ECU Type II or passive bus termination
2 resistor R
tCAN_H
3 resistor R
tCAN_L
4 coupling capacitor C
split
Figure 4 — TPPL passive termination circuit (one side) by using a split termination

5.4 Resistance and capacitance
5.4.1 Internal resistance (R ), internal capacitance (C )
in in
The internal resistance, R , of an ECU is defined as the resistance between CAN_H or CAN_L and ground
in
(ECU_GND) in the recessive state, with the ECU disconnected from CAN_H and CAN_L. The measurement
shall be made with the ECU both powered and unpowered, and the minimum value shall be used to confirm
conformity.
The internal capacitance, C , of an ECU is defined as the internal capacitance between CAN_H or CAN_L and
in
ECU_GND during the recessive state, with the ECU disconnected from CAN_H and CAN_L. The measurement
shall be made with the ECU both powered and unpowered, and the maximum value shall be used to confirm
conformity.
Figure 5 shows the equivalent circuit of internal resistance and internal capacitance of an ECU.
Key
1 ECU
2 internal resistance R
in
3 internal capacitance C
in
Figure 5 — Internal resistance and internal capacitance of ECU in recessive state
5.4.2 Differential internal resistance (R ), differential internal capacitance (C )
diff diff
The differential internal resistance, R , is defined as the resistance seen between CAN_H and CAN_L in the
diff
recessive state, with the ECU disconnected from CAN_H and CAN_L. The measurement shall be made with
the ECU both powered and unpowered, and the minimum value shall be used to confirm conformity.
The differential internal capacitance, C , of an ECU is defined as the capacitance seen between CAN_H and
diff
CAN_L during the recessive state, with the ECU disconnected from CAN_H and CAN_L (see Figure 6). The
measurement shall be made with the ECU both powered and unpowered, and the maximum value shall be
used to confirm conformity.
Figure 6 shows the equivalent circuit of differential internal resistance and differential internal capacitance
of an ECU.
Key
1 ECU
2 differential internal capacitance C
diff
3 differential internal resistance R
diff
Figure 6 — Differential internal resistance and capacitance of ECU in recessive state
5.4.3 Weak termination for stubs
For higher immunity and better EMC performance, TPPL nodes which are connected to the bus may
be realized by using ECU Type I WEAK equipped with a split-termination circuit. In this case the split-
termination shall be realized by using two 750 Ω resistors coupled to ECU_GND by a 47 nF capacitor. The
total number of ECUs Type I WEAK used on a single network segment shall not exceed three units.
In case a ECU Type I WEAK is powered by the PWR/GND lines, the split termination shall be coupled with
GND.
5.5 Bit time requirements
Bus management functions executed within this duration, such as protocol controller synchronization,
network transmission delay compensation and sample point positioning, are specified by the programmable
bit timing logic of the CAN protocol-controller conformant to ISO 11898-1.
Bit rate shall be 250 kbit/s, resulting in a bit time of 4 µs.
Additionally, the following settings shall be configured:
— single sample point method as defined in ISO 11898-1;
— sample point at 80 % ± 3 % of the bit time.
See Annex A for more details.
5.6 AC parameters
Table 1 specifies the AC parameters for an ECU disconnected from the bus. The timing parameters also apply
for an ECU connected to a network segment.

Table 1 — AC parameters of a node disconnected from the bus
Parameter Symbol Min. Nom. Max. Unit Condition
Bit time t 3,998 4,000 4,002 µs 250 kbit/s
B
Measured from 10 % to 90 %
Transition time t — — 500 ns of the voltage of the prevailing
T
state
Internal delay time t 0,0 — 0,9 µs None
ECU
Internal capacitance single ended C 0 — 200 pF 1 MHz
in
Differential internal capacitance C 0 — 100 pF 1 MHz
diff
CMR 40 — — dB DC. to 50 kHz
Common mode rejection
5 MHz may linearly decrease
CMR 10 — — dB
5MHz
between 50 kHz and 5 MHz
6 Network segment requirements
6.1 Twisted quad network segment
A linear twisted quad network segment shall be terminated at each end by a TBC (see Figure 1 and 7.5). The
TBC provides the electrical bias and common mode termination needed to suppress reflections.
The network segment is in the recessive state if the transmitters of all nodes are switched off, with the
mean voltage being generated by the TBCs. A dominant voltage level is sent to the bus signal lines if the
transmitter of at least one of the nodes is switched on. This induces a current through each side of the TBCs,
with the consequence that a differential voltage is produced between the CAN_H and CAN_L lines.
6.2 TPPL network segment
A linear TPPL network segment shall be terminated at each end by a passive termination circuit (see 5.3.2)
to suppress reflections.
The network segment is in the recessive state if the transmitters of all nodes are switched off. A dominant bit
is sent to the bus signal lines if the transmitter of at least one of the nodes is switched on so that a differential
voltage is produced between the CAN_H and CAN_L lines.
7 Electrical requirements
7.1 Electrical operating ranges
7.1.1 General requirements
ECUs shall comply with parameters specified in Table 1, Table 2, Table 7, Table 8, Table 9 and Table 10
throughout their operating temperature range.
7.1.2 ECU DC voltages
Table 2 specifies the absolute maximum DC voltages which can be connected to the bus signal lines without
damage to nodes.
Table 2 — Limits of V and V of bus-disconnected ECU
CAN_H CAN_L
Parameter Symbol Minimum Maximum Unit Conditions
V
CAN_H
Maximum DC voltage −16,0 +16,0 V 12 V nominal supply voltage
V
CAN_L
7.1.3 Power supply DC parameters
7.1.3.1 Architecture power supply DC voltages
Table 3 specifies limits of power supply operating ranges when the nominal supply voltage is 12 V when
considering the system power architecture.
Table 3 — Limits of power supply operating ranges
Parameter Symbol Minimum Maximum Unit Conditions
V
PWR
Voltage operating range +10,0 +16,0 V 12 V nominal supply voltage
V
ECU_PWR
7.1.3.2 Architecture power supply minimum currents
Table 4 specifies the minimum current capacity available from the ECU_PWR and PWR lines when
considering the system power architecture.
Table 4 — Power supply minimum currents
Parameter Symbol Minimum Unit
I 50 A
PWR
Current capacity
I 15 A
ECU_PWR
7.1.3.3 Requirements for DC voltage supplied by tractor through the IBBC
Electrical power on the tractor is supplied by the 12-V supply and alternator system to various electrical
loads on the tractor and implement. To ensure that the tractor can adequately supply electrical power to the
implement, the voltage requirements specified in Table 5 and Table 6 apply at the IBBC/TPPL-BC electrical
supply terminals.
The minimum current available from the tractor implement bus ECU_PWR/ECU_GND lines shall be 15 A
under conditions specified in Table 5.
Table 5 — ECU_PWR limits at tractor IBBC/TPPL-BCs
Parameter Symbol Min Max Unit
ECU power line voltage V 10,5 16,0 V
ECU_DIFF
Conditions for measurement:
—  V = V - V
ECU_DIFF ECU_PWR ECU_GND
—  Measured at tractor IBBC/TPPL-BC terminals
—  15 A DC electrical load
−1
—  Engine at normal operating min range (as defined by manufacturer)
—  Tractor electrical loads on (lights, fans, etc.)
—  Operating temperature range: -30 °C to 85 °C
The minimum current available from the tractor implement bus PWR/GND lines shall be 50 A under the
conditions specified in Table 6.

Table 6 — PWR limits at tractor IBBC/TPPL-BCs
Power line voltage Min Max Unit
V – V 10,5 16,0 V
PWR GND
Conditions for measurement:
—  Measured at tractor IBBC/TPPL-BC terminals
—  50 A DC electrical load
−1
—  Engine at normal operating min range (as defined by manufacturer)
—  Tractor electrical loads on (lights, fans, etc.)
—  Operating temperature range: -30 °C to 85 °C
Maximum simultaneous combined current drawn by an implement through the IBBC shall not exceed 55 A
(continuous current).
NOTE Higher combined currents result in high temperature which can damage the connector or pins.
7.1.3.4 Requirements for DC voltage drop on implements
Electrical power on an implement is supplied by the PWR and ECU_PWR lines through the IBBC.
The implement can provide a rear IBBC receptacle to allow daisy chain connection of additional implements
that acts like electrical loads.
In case of a daisy chain connection, if the voltage drops due to the resistance of supply and return leads on an
implement is too high, the following implement may experience an insufficient operating voltage for correct
operation. To avoid such a situation, and to ensure that an implement can adequately supply electrical power
to the following one, the maximum allowed voltage drop on an implement shall be in accordance to Table 7
and the implement minimum supplied currents shall be in accordance to 7.1.3.2.
Table 7 — Maximum allowed voltage drop in an implement
Power lines voltage Min Max Unit
Implement voltage drop on ECU_
— 1,5 V
a
PWR/ECU_GND lines
Implement voltage drop on PWR/
— 1,5 V
b
GND lines
a
15 A provided at the implement rear IBBC.
b
50 A provided at the implement rear IBBC.
Conditions for measurement (see Figure 7):
—  Measured between implement plug and implement rear IBBC
—  Any load on the implement under test shall be disconnected
—  1,5 V is the total drop of both power supply and return path
—  Operating temperature range: -30 °C to 85 °C

Figure 7 — Voltage-drop measurement
7.1.3.5 Bus-disconnected ECU
The DC parameters for the recessive state of the CAN interface of a powered ECU disconnected from the bus
are specified in Table 8.
Table 8 — DC parameters for recessive state of bus-disconnected ECUs
Parameter Symbol Min. Nom. Max. Unit
V
CAN_H
Bus voltage output behaviour 2,0 2,5 3,0 V
V
CAN_L
Differential output voltage behaviour V −1 200 — 50 mV
diff
g
Differential internal resistance (Type I ECU only) R 2 — 100 kΩ
diff
g
Internal resistance (Type I ECU only) R 5 — 50 kΩ
in
Internal resistance match — −5 — 5 %
Input differential voltage detected as reces- —
V −1,0 0,5 V
diff_IR
sive
The DC parameters for the dominant state of the CAN interface of an ECU disconnected from the bus are
specified in Table 9.
Table 9 — DC parameters for dominant state of bus-disconnected ECUs
Parameter Symbol Min. Max. Unit
V 2,75 5,0
CAN_H
Bus voltage
V 0,0 2,25
CAN_L
V
Differential output voltage V 1,5 3,0
diff_OD
Differential voltage detected as dominant V 1,0 5,0
diff_ID
7.1.3.6 Bus-connected ECU
The DC parameters for the recessive state of the CAN interface of an ECU connected to a network segment
and other ECUs are specified in Table 10.
Table 10 — DC parameters (bus voltage) for bus-connected ECUs in recessive state, without faults
Parameter Symbol Min. Max. Unit Conditions
V
CAN_H
Bus voltage 0,1 4,5 V Measured with respect to GND of each ECU
V
CAN_L
Differential bus voltage V −1 200 50 mV Measured at each ECU connected to CAN_H and CAN_L
diff_R
The DC parameters for the dominant state of the CAN interface of an ECU connected to a network segment
and other ECUs is specified in Table 11.
Table 11 — DC parameters (bus voltage) for bus-connected ECUs in dominant state, without faults
Parameter Symbol Min. Max. Unit Conditions
V — 7,0
CAN_H
Bus voltage V Measured with respect to GND of each ECU
V −2,0 —
CAN_L
3,0 Measured at each ECU connected to bus signal lines
Differential bus voltage V 1,2 V
diff
5,0 During arbitration
7.1.4 Bus voltages (operational)
The bus voltage parameters specified in Table 11 apply when all ECUs (from 2 to 30) are connected to a
terminated network segment (see 5.3). The maximum expected ground offset between ECUs or ECUs and
TBCs on the bus is 2 V.
7.2 Physical media parameters
7.2.1 Unshielded twisted quad cable
Table 12 specifies the physical media parameters for the twisted quad cable (see Figure 9).
Table 12 — Physical media parameters for twisted quad cable
Parameter Symbol Min. Max. Unit Conditions
Measured at 1 MHz between either
Z
H
Impedance 70 80 Ω signal line and ground with TBC_PWR
Z
L
and TBC_RTN grounded
Specific resistance R 0 50 mΩ/m Measured at 20 °C
b
Specific line delay T — — ns/m —
p
C 0 75 pF/m Between CAN_H and CAN_L
b
Specific capacitance
C 0 110 pF/m Between adjacent conductors
a
Cross-section to be formed from 16 or
Conductor size A — — mm greater strands of 32 AWG tinned or
c
bare copper.
Conductor twist — 48 52 mm/turn —
Continuous operation without degra-
Temperature range T −40 +85 °C
dation
Table 13 recommends colours for the insulation of the wires in the cable. The manufacturer is recommended
to provide a detailed description of wires colour in the technical documentation.
Table 13 — Recommended colours for conductor insulation
Colour Conductor insulation
Red TBC_PWR
Yellow CAN_H
Black TBC_RTN
Green CAN_L
7.2.2 Unshielded twisted pair
Table 14 specifies the physical media parameters for unshielded twisted pair cable (see Figure 8).

Table 14 — Physical media parameters for twisted pair cable
Parameter Symbol Min. Nom. Max. Unit Conditions
Three-meter sample length meas-
ured at 1 MHz between the two
Impedance Z 108 120 132 Ω
signal wires, using open/short
method.
Specific resistance R — 25 50 mΩ/m Measured at 20 °C
b
Specific line delay T — 5,0 — ns/m
p
C — 40 75 pF/m Between CAN_H and CAN_L
b
Specific capacitance
Conductor twist — 24 — 52 mm/turn —
Temperature range T −40 — +85 °C
Key
1 unshielded twisted quad
2 unshielded twisted pair
A conductor size
c
D conductor insulation diameter
ci
T Jacket size
j
Figure 8 — Cable cross-section
The bus line consists of CAN_H and CAN_L conductors. Table 15 specifies the recommended wire jacket
colours for the CAN_H and CAN_L (see Figure 8).
Table 15 — Recommended colours for conductor insulation
Colour Conductor insulation
Yellow CAN_H
Green CAN_L
7.3 Topology of twisted quad physical layers
7.3.1 General
To avoid cable reflections, the wiring of a network segment should have a bus line topology with short stubs
(see Figure 10). To minimize standing waves, nodes should have different distances (d) on the network
segment and stub lengths should have different lengths (S). The dimensional parameters of this topology as
shown in Figure 10 are specified in Table 16.
Consider not to cluster nodes.

Key
1 terminating bias circuit (TBC)
2 2 wires, CAN_H and CAN_L
3 twisted quad cable
4 ECU 1
5 ECU 2
6 ECU n-1
7 ECU n
d distance between two nodes (see Table 16)
S stub length (see Table 16)
l end to end bus length (see Table 16)
bus
Figure 9 — Topology of bus-segment wiring
Table 16 — Topology dimensional parameters
Parameter Symbol Min. Max Unit Conditions
Bus length l - 40 m Not including stubs
bus
Stub length S 0 1 m —
Node distance d 0,1 - m Random
7.3.2 ECU connection to TBC_PWR and TBC_RTN
To sense the status of the network, each ECU on the bus can provide a pin for TBC_PWR and TBC_RTN.
Loading limits are specified in Table 17.
Table 17 — ECU loading of TBC_PWR and TBC_RTN
Parameter Symbol Min. Max. Unit Conditions
Measured between TBC_PWR and any other signal
R 30 — kΩ
TBC_PWR
in ECU
DC resistance
R 30 — kΩ Measured between TBC_RTN and any other signal in ECU
TBC_RTN
Measured at 1 MHz between TBC_PWR and any other
C — 200 nF
TBC_PWR
signal in ECU
Capacitance
Measured at 1 MHz between TBC_RTN and any other
C — 200 nF
TBC_RTN
signal in ECU
7.3.3 Power for TBC_PWR and TBC_RTN
TBC_PWR and TBC_RTN for a given network segment shall be supplied at a single point. This sin
...

TC /SC ISO/FDIS 11783-2
ISO/TC 23/SC 19
Secretariat: DIN
i
Date: 2026-09-25
Tractors and machinery for agriculture and forestry — Serial control
and communications data network —
Part 2:
Physical layer
Tracteurs et matériels agricoles et forestiers — Réseaux de commande et de communication de données en
série —
Partie 2: Couche physique
FDIS stage
All rights reserved. Unless otherwise specified
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iii
Contents Page
Foreword . v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 3
5 General requirements . 3
5.1 Network physical layer . 3
5.2 Physical media . 3
5.3 Termination circuit . 4
5.4 Resistance and capacitance . 8
5.5 Bit time requirements . 10
5.6 AC parameters . 11
6 Network segment requirements . 11
6.1 Twisted quad network segment . 11
6.2 TPPL network segment . 11
7 Electrical requirements . 11
7.1 Electrical operating ranges . 11
7.2 Physical media parameters . 16
7.3 Topology of twisted quad physical layers . 18
7.4 Topology of twisted pair physical layer . 20
7.5 TBC parameters . 23
7.6 Termination circuit parameters . 24
7.7 Connectors . 25
8 Conformance test plan . 71
8.1 General requirements . 71
8.2 Internal resistance . 71
8.3 Internal differential resistance . 73
8.4 ECU recessive input threshold . 73
8.5 ECU dominant input threshold. 74
8.6 ECU internal delay time . 75
8.7 Electrostatic discharge (ESD) . 77
9 Bus failure and fault confinement . 77
9.1 General. 77
9.2 Loss of network connection . 77
9.3 Node power or ground loss . 77
9.4 Reaction to power-supply voltage disturbances . 77
9.5 Network disruption during connection, disconnection or power-up . 78
9.6 Open and short failures . 78
Annex A (informative) Protocol controller timing and naming . 83
Annex B (informative) Examples of physical layer circuits . 87
Annex C (informative) Optional ECU stub connector . 98
Bibliography . 101

iv
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). 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-governmental, 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.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of
ISO documentsdocument should be noted. This document was drafted in accordance with the editorial rules
of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawnISO draws attention to the possibility that some of the elementsimplementation of this
document may beinvolve the subjectuse of (a) patent(s). ISO takes no position concerning the evidence,
validity or applicability of any claimed patent rights in respect thereof. As of the date of publication of this
document, ISO had not received notice of (a) patent(s) which may be required to implement this document.
However, implementers are cautioned that this may not represent the latest information, which may be
obtained from the patent database available at www.iso.org/patents. ISO shall not be held responsible for
identifying any or all such patent rights. Details of any patent rights identified during the development of the
document will be in the Introduction and/or on the ISO list of patent declarations received (see ).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation onof the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT)), see
www.iso.org/iso/foreword.htmlthe following URL: .
This document was prepared by Technical Committee ISO/TC 23, Tractors and machinery for agriculture and
forestry, Subcommittee SC 19, Agricultural electronics.
This fourth edition cancels and replaces the third edition (ISO 11783-2:2019), which has been technically
revised. It also incorporates the Technical Corrigendum ISO 11783-2:2012/Cor 1:2012. The main changes
compared to the previous edition are as follows:
— The main changes are as follows:
— separation of requirements for ECU designers and for system designers;
— — updateupdating of electrical requirements to the current state of the art;
— — alignment of the document to ISO/IEC directives;
— — restructuring and rationalization of the document.
A list of all the parts in the ISO 11783 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
v
Introduction
The ISO 11783 series specifies a communications system for agricultural equipment based on the ISO 11898-
1 CAN protocol. The SAE J1939 series1), on which parts of ISO 11783 series are based, were developed jointly
for use in truck and bus, construction, and agriculture applications. Joint documents have been completed to
allow electronic units that meet the truck and bus SAE J1939 specifications to be used by agricultural and
forestry equipment with minimal changes. General information on the ISO 11783 series can be found in ISO
11783-1.
The purpose of the ISO 11783 series is to provide an open, interconnected system for on-board electronic
systems. It is intended to enable electronic control units (ECUs) to communicate with each other, providing a
standardized system.
vi
Tractors and machinery for agriculture and forestry — Serial control
and communications data network —
Part 2:
Physical layer
IMPORTANT — This document contains colours which are considered to be useful for the correct
understanding of the document. Users should therefore consider printing this document using a
colour printer.
1 Scope
This document specifies the device interface using the CAN HS (high-speed) physical medium attachment
(PMA) sublayer, as given in ISO 11898-2, and the physical coding sublayer (PCS)), as given in ISO 11898-1.
Additionally, this documentIt specifies two physical medium-dependent sublayers: a) un-shielded, twisted-
quad cable and b) un-shielded, twisted-pair cable.
a) un-shielded, twisted-quad cable, and
a)b) un-shielded, twisted-pair cable.
NOTE Where not differentlyotherwise specified, requirements are valid for both twisted quad physical layer (TQPL)
and twisted pair physical layer (TPPL).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 1724:2003, Road vehicles — Connectors for the electrical connection of towing and towed vehicles — 7-pole
connector type 12 N (normal) for vehicles with 12 V nominal supply voltage
ISO 11783-1:2017, Tractors and machinery for agriculture and forestry — Serial control and communications
data network — Part 1: General standard for mobile data communication
ISO 11898-1:2024, Road vehicles — Controller area network (CAN) — Part 1: Data link layer and physical coding
sublayer
ISO 11898-2:20242026, Road vehicles — Controller area network (CAN) — Part 1: High-speed physical medium
attachment (PMA) sublayer
SAE J1939-11:2016, Physical Layer, 250 Kbps, Twisted Shielded Pair
SAE J1939-13:2024, Off-Board Diagnostic Connector
SAE J1939-15:2018, Physical Layer, 250 Kbps, Un-Shielded Twisted Pair (UTP)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11783-1 and the following apply.
ISO and IEC maintain terminologicalterminology databases for use in standardization at the following
addresses:
— — ISO Online browsing platform: available at https://www.iso.org/obp
— — IEC Electropedia: available at https://www.electropedia.org/
3.1 3.1
ECU Type I
electronic control unit without internal termination
3.2 3.2
ECU Type I WEAK
electronic control unit with split termination coupled to ECU_GND with a capacitor and that is used for stubs
only (see 5.54.3)
Field Code Changed
3.3 3.3
ECU Type II
electronic control unit with a internal termination circuit
3.4 3.4
internal delay time
the sum of all asynchronous delays that occur along the transmission and reception path within the ECU,
relative to the bit timing logic unit of the CAN implementation (see A.2)
Field Code Changed
3.5 3.5
twisted pair physical layer
TPPL
250 kbit/s, unshielded, twisted pair cable-based network layer intended to be used as an alternate to the
twisted quad physical layer and that is backward compatible with machines based on a twisted quad physical
layer
3.6 3.6
machine
forestry or agricultural tractor or mounted, semi-mounted, towed or self-propelled implement
3.7 3.7
network segment
single CAN network using a linear topology configuration with stubs
3.8
3.8
node
see definition assembly, linked to a communication network, capable of communicating across the network
according to a communication protocol specification
Note 1 to entry: A node can be in one of four states: integrating, idle, receiver or transmitter.
Note 2 to entry: A node operating in a controller area network (CAN) is called a CAN node.
[SOURCE: ISO 11898 - -1 Clause:2024, 3.39, modified — definition has been modified to exclude further
information.]
3.9 3.9
twisted quad physical layer
TQPL
250 kbit/s, unshielded, twisted quad cable-based network layer
4 Abbreviated terms
IBBC Implement Bus Breakaway Connector (socket)
IBBP Implement Bus Breakaway Plug
CAN controller area network
PMA physical medium attachment
PCS physical Coding Sublayer
ECU Electronic Control Unit
PWR power
GND ground
DC direct current
MDI medium dependent interface
AC alternating Current
TBC Terminating Bias Circuit
TBC_GND Terminating Bias Circuit Ground
TBC_RTN Terminating Bias Circuit Return
5 General requirements
5.1 Network physical layer
The physical coding sublayer shall complybe in accordance with CAN CC requirements as given in ISO 11898-
1:2024 (, Clause 7);; it is implemented in CAN protocol controller units using a non-return-to-zero (NRZ)
coding. The physical medium attachment (PMA) sublayer shall complybe in accordance with the requirements
for high-speed PMA entities supporting bit rates up to 1 Mbit/s as given in ISO 11898-2:2024 (see2026,
Table 15 in particular); it is implemented in so-called high-speed (HS) CAN transceiver units.
The physical medium-dependent (PMD) sublayer is specified in the following subclauses. This includes
requirements for the ECU designer: 5.4, 5.5, 7.1.2, 7.1.3.5, 7.1.3.5.
Field Code Changed
The requirements for network designers are given in: 5.2, 5.3, Clause 6, 7.1.3.1, 7.1.3.2, 7.1.3.3, 7.1.3.4, 7.1.4,
7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.4, 7.5, 7.6, 7.7.
5.2 Physical media
This document defines two types of physical media.
a) a) TQPL: shall be composed by four conductors, two of them, designated CAN_H and CAN_L, are
driven with the electrical communication signals. The names of the ECU connector 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 network segment.
b) b) TPPL: shall be composed by a twisted pair cable as described in SAE J1939-15. The conductors,
designated CAN_H and CAN_L, are driven with the MDI as specified in ISO 11898-2. The names of the ECU
connector pins corresponding to these conductors are also designated CAN_H and CAN_L.
5.3 Termination circuit
5.3.1 Twisted quad network segment
The bus signal lines of a twisted quad network segment shall be electrically terminated at each end by a
terminating bias circuit. When a node transceiver is on, a current (I) flow is induced that is either sunk by the
CAN_H termination or is sourced by the CAN_L termination. This TBC shall be located outside the ECU housing,
to ensure bus bias and termination when the ECU is disconnected (see Figure 1).
Field Code Changed
Key
1 ECU no. 1
2 ECU no. n
3 terminating bias circuit (TBC)
4 power for TBC_PWR and TBC_RTN
5 twisted quad cable
1 ECU no. 1
2 ECU no. n
3 terminating bias circuit (TBC)
4 power for TBC_PWR and TBC_RTN
5 twisted quad cable
Figure 1 — Physical layer functional diagram
5.3.2 Twisted pair physical layer network segment
The bus signal lines of a TPPL network segment shall be electrically terminated at each end using a terminating
resistor R (see Figure 2) or with a passive split termination circuit using two resistors R and R
t tCAN_H tCAN_L
coupled to ground by a capacitor C (see Figure 4). 7.6 defines electrical requirements for the two
split
alternatives.
Figure 3 shows the termination for a network segment, using Type II ECUs.
The system designer should take care that the network segment is terminated at one or both ends. Type II
ECUs shall be marked. A Type II ECU shall only be used at one or both ends of a bus, even when the machine
is attached to another machine by an IBBC. Type II ECUs shall only be powered by ECU_PWR/ECU_GND.
Key
1 ECU Type I No. 1
2 ECU Type I No. n
3 unshielded twisted pair
4 terminating resistors Rt
1 ECU Type I No. 1
2 ECU Type I No. n
3 unshielded twisted pair
4 terminating resistors R
t
Figure — 2 — TPPL passive termination circuit by using single resistors at each end of the network
segment
Key
1 ECU Type I
2 ECU Type II with internal R
t
3 unshielded twisted pair
1 ECU Type I
2 ECU Type II with internal Rt
3 unshielded twisted pair
Figure — 3 — TPPL passive termination circuit (one side) by using an ECU Type II as a termination

Key
1 ECU Type II or passive bus termination
2 Resistor RtCAN_H
3 Resistor RtCAN_L
4 coupling capacitor C
split
1 ECU Type II or passive bus termination
2 resistor RtCAN_H
3 resistor RtCAN_L
4 coupling capacitor Csplit
Figure — 4 — TPPL passive termination circuit (one side) by using a split termination
5.4 Resistance and capacitance
5.4.1 Internal resistance (R ), internal capacitance (C )
in in
The internal resistance, R , of an ECU is defined as the resistance between CAN_H or CAN_L and ground
in
(ECU_GND) in the recessive state, with the ECU disconnected from CAN_H and CAN_L. The measurement shall
be made with the ECU both powered and unpowered, and the minimum value shall be used to confirm
conformity.
The internal capacitance, C , of an ECU is defined as the internal capacitance between CAN_H or CAN_L and
in
ECU_GND during the recessive state, with the ECU disconnected from CAN_H and CAN_L. The measurement
shall be made with the ECU both powered and unpowered, and the maximum value shall be used to confirm
conformity.
Figure 5 shows the equivalent circuit of internal resistance and internal capacitance of an ECU.
Key
1 ECU
2 internal resistance Rin
3 internal capacitance C
in
1 ECU
2 internal resistance Rin
3 internal capacitance Cin
Figure — 5 — Internal resistance and internal capacitance of ECU in recessive state
5.4.2 Differential internal resistance (R ), differential internal capacitance (C )
diff diff
The differential internal resistance, R , is defined as the resistance seen between CAN_H and CAN_L in the
diff
recessive state, with the ECU disconnected from CAN_H and CAN_L. The measurement shall be made with the
ECU both powered and unpowered, and the minimum value shall be used to confirm conformity.
The differential internal capacitance, C , of an ECU is defined as the capacitance seen between CAN_H and
diff
CAN_L during the recessive state, with the ECU disconnected from CAN_H and CAN_L (see Figure 6). The
measurement shall be made with the ECU both powered and unpowered, and the maximum value shall be
used to confirm conformity.
Figure 6 shows the equivalent circuit of differential internal resistance and differential internal capacitance of
an ECU.
Key
1 ECU
2 Differential internal capacitance Cdiff
3 Differential internal resistance Rdiff
1 ECU
2 differential internal capacitance Cdiff
3 differential internal resistance Rdiff
Figure — 6 — Differential internal resistance and capacitance of ECU in recessive state
5.4.3 Weak termination for stubs
For higher immunity and better EMC performance, TPPL nodes which are connected to the bus may be
realized by using ECU Type I WEAK equipped with a split-termination circuit. In this case the split-termination
shall be realized by using two 750 Ω resistors coupled to ECU_GND by a 47 nF capacitor. The total number of
ECUs Type I WEAK used on a single network segment shall not exceed three units.
In case a ECU Type I WEAK is powered by the PWR/GND lines, the split termination shall be coupled with
GND.
5.5 Bit time requirements
Bus management functions executed within this duration, such as protocol controller synchronization,
network transmission delay compensation and sample point positioning, are specified by the programmable
bit timing logic of the CAN protocol-controller conformant to ISO 11898-1.
Bit rate shall be 250 kbit/s, resulting in a bit time of 4 µs.
Additionally, the following settings shall be configured:
— — single sample point method as defined in ISO 11898-1;
— — sample point at 80 % ± 3 % of the bit time.
See Annex A for more details.
5.6 AC parameters
Table 1 specifies the AC parameters for an ECU disconnected from the bus. The timing parameters also apply
for an ECU connected to a network segment.
Table 1 — AC parameters of a node disconnected from the bus
Parameter Symbol Min. Nom. Max. Unit Condition
Bit time tB 3,998 4,000 4,002 µs 250 kbit/s
Measured from 10 % to 90 % of
Transition time tT — — 500 ns the voltage of the prevailing
state
Internal delay time tECU 0,0 — 0,9 µs None
Internal capacitance single
C 0 — 200 pF 1 MHz
in
ended
Differential internal capacitance Cdiff 0 — 100 pF 1 MHz
CMR 40 — — dB DC. to 50 kHz
Common mode rejection
5 MHz may linearly decrease
CMR5MHz 10 — — dB
between 50 kHz and 5 MHz
6 Network segment requirements
6.1 Twisted quad network segment
A linear twisted quad network segment shall be terminated at each end by a TBC (see Figure 1 and 7.5). The
TBC provides the electrical bias and common mode termination needed to suppress reflections.
The network segment is in the recessive state if the transmitters of all nodes are switched off, with the mean
voltage being generated by the TBCs. A dominant voltage level is sent to the bus signal lines if the transmitter
of at least one of the nodes is switched on. This induces a current through each side of the TBCs, with the
consequence that a differential voltage is produced between the CAN_H and CAN_L lines.
6.2 TPPL network segment
A linear TPPL network segment shall be terminated at each end by a passive termination circuit (see 5.3.2) to
suppress reflections.
The network segment is in the recessive state if the transmitters of all nodes are switched off. A dominant bit
is sent to the bus signal lines if the transmitter of at least one of the nodes is switched on so that a differential
voltage is produced between the CAN_H and CAN_L lines.
7 Electrical requirements
7.1 Electrical operating ranges
7.1.1 General requirements
ECUs shall comply with parameters specified in Table 1, Table 2, Table 7, Table 8, Table 7, Table 8, Table 9,
Table 9 and Table 10Table 10 throughout their operating temperature range.
7.1.2 ECU DC voltages
Table 2Table 2 specifies the absolute maximum DC voltages which can be connected to the bus signal lines
without damage to nodes.
Table 2 — Limits of V and V of bus-disconnected ECU
CAN_H CAN_L
Parameter Symbo Minimu Maximu Uni Conditions
l m m t
V
CAN_H
Maximum DC voltage −16,0 +16,0 V 12 V nominal supply voltage
VCAN_L
7.1.3 Power supply DC parameters
7.1.3.1 Architecture power supply DC voltages
Table 3 specifies limits of power supply operating ranges when the nominal supply voltage is 12 V when
considering the system power architecture.
Table 3 — Limits of power supply operating ranges
Parameter Symbol Minimum Maximum Unit Conditions
VPWR
Voltage operating range +10,0 +16,0 V 12 V nominal supply voltage
VECU_PWR
7.1.3.2 Architecture power supply minimum currents
Table 4 specifies the minimum current capacity available from the ECU_PWR and PWR lines when considering
the system power architecture.
Table 4 — Power supply minimum currents
Parameter Symbol Minimu Unit
m
IPWR 50 A
Current capacity
I 15 A
ECU_PWR
7.1.3.3 Requirements for DC voltage supplied by tractor through the IBBC
Electrical power on the tractor is supplied by the 12-V supply and alternator system to various electrical loads
on the tractor and implement. To ensure that the tractor can adequately supply electrical power to the
implement, the voltage requirements specified in Table 5 and Table 6 apply at the IBBC/TPPL-BC electrical
supply terminals.
The minimum current available from the tractor implement bus ECU_PWR/ECU_GND lines shall be 15 A under
conditions specified in Table 5.
Field Code Changed
Table 5 — ECU_PWR limits at tractor IBBC/TPPL-BCs
Parameter Symbol Min Max Unit
ECU power line V
ECU_DIFF
10,5 16,0 V
voltage
Parameter Symbol Min Max Unit
Conditions for measurement:
—  VECU_DIFF = VECU_PWR - VECU_GND
—  Measured at tractor IBBC/TPPL-BC terminals
—  15 A DC electrical load
−1
—  Engine at normal operating min range (as defined by manufacturer)
—  Tractor electrical loads on (lights, fans, etc.)
—  Operating temperature range: -30 °C to 85 °C
The minimum current available from the tractor implement bus PWR/GND lines shall be 50 A under the
conditions specified in Table 6.
Field Code Changed
Table 6 — PWR limits at tractor IBBC/TPPL-BCs
Power line voltage Min Max Unit
VPWR – VGND 10,5 16,0 V
Conditions for measurement:
—  Measured at tractor IBBC/TPPL-BC terminals
—  50 A DC electrical load
−1
—  Engine at normal operating min range (as defined by manufacturer)
—  Tractor electrical loads on (lights, fans, etc.)
—  Operating temperature range: -30 °C to 85 °C
Maximum simultaneous combined current drawn by an implement through the IBBC shall not exceed 55 A
(continuous current).
NOTE : Higher combined currents would result in high temperature which can damage the connector or pins.
7.1.3.4 Requirements for DC voltage drop on implements
Electrical power on an implement is supplied by the PWR and ECU_PWR lines through the IBBC.
The implement can provide a rear IBBC receptacle to allow daisy chain connection of additional implements
that acts like electrical loads.
In case of a daisy chain connection, if the voltage drops due to the resistance of supply and return leads on an
implement is too high, the following implement may experience an insufficient operating voltage for correct
operation. To avoid such a situation, and to ensure that an implement can adequately supply electrical power
to the following one, the maximum allowed voltage drop on an implement shall be in accordance to Table 7
and the implement minimum supplied currents shall be in accordance to 7.1.3.2.
Field Code Changed
Table 7 — Maximum allowed voltage drop in an implement
Power lines voltage Min Max Unit
Implement voltage drop on
— 1,5 V
a
ECU_PWR/ECU_GND lines
Implement voltage drop on PWR/
— 1,5 V
b
GND lines
a 15 A provided at the implement rear IBBC.
b 50 A provided at the implement rear IBBC.
Conditions for measurement (see Figure 7Figure 7):):
Power lines voltage Min Max Unit
—  Measured between implement plug and implement rear IBBC
—  Any load on the implement under test shall be disconnected
—  1,5 V is the total drop of both power supply and return path
—  Operating temperature range: -30 °C to 85 °C

Figure 7 — Voltage-drop measurement
7.1.3.5 Bus-disconnected ECU
The DC parameters for the recessive state of the CAN interface of a powered ECU disconnected from the bus
are specified in Table 8.
Field Code Changed
Table 8 — DC parameters for recessive state of bus-disconnected ECUs
Parameter Symbol Min. Nom. Max. Unit
VCAN_H
Bus voltage output behaviour 2,0 2,5 3,0 V
V
CAN_L
−12001 —
Differential output voltage behaviour Vdiff 50 mV
Differential internal resistance (Type I ECU —
Rdiff 2 100 kΩ
g
only)
g
Internal resistance (Type I ECU only) Rin 5 — 50 kΩ
Internal resistance match — −5 — 5 %
Parameter Symbol Min. Nom. Max. Unit
Input differential voltage detected as —
V −1,0 0,5 V
diff_IR
recessive
The DC parameters for the dominant state of the CAN interface of an ECU disconnected from the bus are
specified in Table 9.
Field Code Changed
Table 9 — DC parameters for dominant state of bus-disconnected ECUs
Parameter Symbol Min. Max. Unit
V 2,75 5,0
CAN_H
Bus voltage
V 0,0 2,25
CAN_L
V
Differential output voltage V 1,5 3,0
diff_OD
Differential voltage detected as dominant V 1,0 5,0
diff_ID
7.1.3.6 Bus-connected ECU
The DC parameters for the recessive state of the CAN interface of an ECU connected to a network segment and
other ECUs are specified in Table 10.
Field Code Changed
Table 10 — DC parameters (bus voltage) for bus-connected ECUs in recessive state, without faults
Parameter Symbol Min. Max. Unit Conditions
VCAN_H
Bus voltage 0,1 4,5 V Measured with respect to GND of each ECU
VCAN_L
−120
Measured at each ECU connected to CAN_H and
Differential bus voltage V 01 20 50 mV
diff_R
CAN_L
The DC parameters for the dominant state of the CAN interface of an ECU connected to a network segment and
other ECUs is specified in Table 11.
Field Code Changed
Table 11 — DC parameters (bus voltage) for bus-connected ECUs in dominant state, without faults
Parameter Symbol Min. Max. Unit Conditions
VCAN_H — 7,0
Bus voltage V Measured with respect to GND of each ECU
VCAN_L −2,0 —
Measured at each ECU connected to bus signal
3,0
lines
Differential bus voltage V 1,2 V
diff
5,0 During arbitration
7.1.4 Bus voltages (operational)
The bus voltage parameters specified in Table 11 apply when all ECUs (from 2 to 30) are connected to a
terminated network segment (see 5.3). The maximum expected ground offset between ECUs or ECUs and TBCs
on the bus is 2 V.
7.2 Physical media parameters
7.2.1 Unshielded twisted quad cable
Table 12 specifies the physical media parameters for the twisted quad cable (see Figure 9Figure 9).).
Table 12 — Physical media parameters for twisted quad cable
Parameter Symbol Min. Max. Unit Conditions
Measured at 1 MHz between either
ZH
Impedance 70 80 Ω signal line and ground with TBC_PWR
Z
L
and TBC_RTN grounded
Specific resistance Rb 0 50 mΩ/m Measured at 20 °C
Specific line delay T — — ns/m —
p
Cb 0 75 pF/m Between CAN_H and CAN_L
Specific capacitance
Ca 0 110 pF/m Between adjacent conductors
Cross-section to be formed from 16 or
Conductor size Ac — — mm greater strands of 32 AWG tinned or
bare copper.
Conductor twist — 48 52 mm/turn —
Continuous operation without
Temperature range T −40 +85 °C
degradation
Table 13 recommends colours for the insulation of the wires in the cable. The manufacturer is recommended
to provide a detailed description of wires colour in the technical documentation.
Table 13 — Recommended colours for conductor insulation
Colour Conductor insulation
Red TBC_PWR
Yellow CAN_H
Black TBC_RTN
Green CAN_L
7.2.2 Unshielded twisted pair
Table 14 specifies the physical media parameters for unshielded twisted pair cable (see Figure 8)).
Table 14 — Physical media parameters for twisted pair cable
Symb
Parameter Min. Nom. Max. Unit Conditions
ol
Three-meter sample length
measured at 1 MHz between the
Impedance Z 108 120 132 Ω
two signal wires, using
open/short method.
Specific resistance Rb — 25 50 mΩ/m Measured at 20 °C
Specific line delay Tp — 5,0 — ns/m
Symb
Parameter Min. Nom. Max. Unit Conditions
ol
C — 40 75 pF/m Between CAN_H and CAN_L
b
Specific capacitance
Conductor twist — 24 — 52 mm/turn —
Temperature range T −40 — +85 °C

Key
1 unshielded twisted quad
2 unshielded twisted pair
A conductor size
c
D conductor insulation diameter
ci
Tj Jacket size
1 unshielded twisted quad
2 unshielded twisted pair
Ac conductor size
D conductor insulation diameter
ci
T Jacket size
j
Figure 8 — Cable cross-section
The bus line consists of CAN_H and CAN_L conductors. Table 15 specifies the recommended wire jacket
colours for the CAN_H and CAN_L (see Figure 8 and ).
Table 15 — Recommended colours for conductor insulation
Colour Conductor insulation
Yellow CAN_H
Green CAN_L
7.3 Topology of twisted quad physical layers
7.3.1 General
To avoid cable reflections, the wiring of a network segment should have a bus line topology with short stubs
(see Figure 10Figure 10).). To minimize standing waves, nodes should have different distances (d) on the
network segment and stub lengths should have different lengths (S). The dimensional parameters of this
topology as shown in Figure 10Figure 10 are specified in Table 16.
Consider not to cluster nodes.

Key
1 terminating bias circuit (TBC)
2 2 wires, CAN_H and CAN_L
3 twisted quad cable
4 ECU 1
5 ECU 2
6 ECU n-1
7 ECU n
d distance between two nodes (see Table 16)
S stub length (see Table 16)
lbus end to end bus length (see Table 16
1 terminating bias circuit (TBC)
2 2 wires, CAN_H and CAN_L
3 twisted quad cable
4 ECU 1
5 ECU 2
6 ECU n-1
7 ECU n
d distance between two nodes (see Table 16)

S stub length (see Table 16)
lbus End to end bus length (see Table 16)
)
Figure 9 — Topology of bus-segment wiring
Table 16 — Topology dimensional parameters
Symbo
Parameter Min. Max Unit Conditions
l
Bus length l - 40 m Not including stubs
bus
Stub length S 0 1 m —
Node distance d 0,1 - m Random
7.3.2 ECU connection to TBC_PWR and TBC_RTN
To sense the status of the network, each ECU on the bus can provide a pin for TBC_PWR and TBC_RTN. Loading
limits are specified in Table 17.
Field Code Changed
Table 17 — ECU loading of TBC_PWR and TBC_RTN
Parameter Symbol Min. Max. Unit Conditions
Measured between TBC_PWR and any other signal
R 30 — kΩ
TBC_PWR
in ECU
DC resistance
Measured between TBC_RTN and any other signal
RTBC_RTN 30 — kΩ
in ECU
Measured at 1 MHz between TBC_PWR and any
CTBC_PWR — 200 nF
other signal in ECU
Capacitance
Measured at 1 MHz between TBC_RTN and any
CTBC_RTN — 200 nF
other signal in ECU
7.3.3 Power for TBC_PWR and TBC_RTN
TBC_PWR and TBC_RTN for a given network segment shall be supplied at a single point. This single connection
point shall comply with the requirements specified in Table 17Table 17. Filtering and regulation can be
provided within the module providing this interconnection (see Annex BAnnex B).).
7.4 Topology of twisted pair physical layer
7.4.1 General specifications
The main topology shall be the same as the TQPL (see 7.37.3).). The ECUs can be connected to the network
segment in accordance to 7.4.2, , 7.4.3, 7.4.4.
— The minimum distance between two stubs/splices shall be 50 cm.
7.4.2 Single stub
The single stub is intended to connect one single ECU to the network segment. The maximum stub length shall
be 3,0 m, see Figure 10.
Field Code Changed
Key
1 ECU
2 2 wires, CAN_H and CAN_L
S stub length
1 ECU
2 2 wires, CAN_H and CAN_L
S stub length
Figure 10 — Single stub
7.4.3 Compound stub
A compound stub (see Figure 11) is made by a single stub spliced at the end. The maximum number of splices
shall be three and each one shall have a different length. The maximum length of the main stub shall be
1,5m5 m. The minimum length of a splice shall be 0,2m2 m and the maximum length shall be 0,5m5 m.
There shall be only one compound stub on a network segment.

Key
1 ECU
2 2 wires, CAN_H and CAN_L
S stub length
s splice length
1 ECU
2 2 wires, CAN_H and CAN_L
S stub length
s splice length
Figure 11 — Compound stub
7.4.4 Multiple splice
A multiple splice (see Figure 12) is the connection of more than one stub to a single joint point on the bus. The
maximum number of stubs shall be three. The stubs shall have different length with a minimum value of 0,5 m
up to a maximum of 1,5 m.
There shall be only one multiple splice on a network segment.

Key
1 ECU
2 2 wires, CAN_H and CAN_L
Sm minimum stub length
S maximum stub length
M
1 ECU
2 2 wires, CAN_H and CAN_L
Sm minimum stub length
S maximum stub length
M
Figure 12 — Multiple splice
7.5 TBC parameters
The terminating bias circuit for twisted quad physical layers connects all four conductors of the twisted quad
cable, not only providing the bias for the CAN_H and CAN_L signals but also the common mode resistive
termination for the respective conductors. Figure 13 illustrates the Thévenin-equivalent circuit required by
the TBC, of which there shall be one for each end of network segment (see Annex BAnnex B). ). Table 18
specifies the TBC parameters.
Table 18 — Terminating bias circuit (TBC) parameters
Min
Parameter Symbol Max. Unit Conditions
.
U shall be capable of sourcing
H
CAN_H bias voltage UCAN_H 2,25 2,75 V
5 mA and sinking 90 mA to GND
U shall be capable of sourcing
L
CAN_L bias voltage UCAN_L 2,25 2,75 V
90 mA and sinking 500 µA
UCAN_L-
CAN bias tracking −0,1 0,1 V —
UCAN_H
CAN_H terminating resistance RtCAN_H 70 80 Ω Thévenin equivalent of TBC
CAN_L terminating resistance RtCAN_L 70 80 Ω Thévenin equivalent of TBC
Resistance tracking is specified as
RtCAN_H/((1/2)(RtCAN_H + RtCAN_L))
Resistance matching  0,98 1,02 —
and RtCAN_L/((1/2)(RtCAN_H +
RtCAN_L))
Parallel capacitance Cp — 15 pF CAN_H or CAN_L to ground
Series inductance L — 0,1 µH —
s
25 mV peak to peak ripple in
Operating supply voltage UTBC_PWR 8 16 V
20 kHz to 2 MHz range
Shorts to
Fault tolerance on bus signal lines — — — Continuous
supply
Shorts to
Fault tolerance on bus signal lines — — — Continuous
ground
Key
1 CAN_H terminating resistance RtCAN_H
2 CAN_L terminating resistance RtCAN_L
3 CAN_H bias voltage U
CAN_H
4 CAN_L bias voltage U
CAN_L
1 CAN_H terminating resistance RtCAN_H
2 CAN_L terminating resistance RtCAN_L
3 CAN_H bias voltage UCAN_H
4 CAN_L bias voltage U
CAN_L
Fi
...

PROJET FINAL
Norme
internationale
ISO/TC 23/SC 19
Tracteurs et matériels agricoles et
Secrétariat: DIN
forestiers — Réseaux de commande
Début de vote:
et de communication de données en
2026-10-09
série —
Vote clos le:
2026-12-04
Partie 2:
Couche physique
Tractors and machinery for agriculture and forestry — Serial
control and communications data network —
Part 2: Physical layer
LES DESTINATAIRES DU PRÉSENT PROJET SONT
INVITÉS À PRÉSENTER, AVEC LEURS OBSERVATIONS,
NOTIFICATION DES DROITS DE PROPRIÉTÉ DONT ILS
AURAIENT ÉVENTUELLEMENT CONNAISSANCE ET À
FOURNIR UNE DOCUMENTATION EXPLICATIVE.
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DU POINT DE VUE DE LEUR POSSI BILITÉ DE DEVENIR DES
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SERVIR DE RÉFÉRENCE DANS LA RÉGLEMENTATION
NATIONALE.
Numéro de référence
PROJET FINAL
Norme
internationale
ISO/TC 23/SC 19
Tracteurs et matériels agricoles et
Secrétariat: DIN
forestiers — Réseaux de commande
Début de vote:
et de communication de données en
2026-10-09
série —
Vote clos le:
2026-12-04
Partie 2:
Couche physique
Tractors and machinery for agriculture and forestry — Serial
control and communications data network —
Part 2: Physical layer
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Publié en Suisse
Numéro de référence
ii
Sommaire Page
Avant-propos .v
Introduction .vi
1 Domaine d’application . 1
2 Références normatives . 1
3 Termes et définitions . 1
4 Abréviations . 3
5 Exigences générales . . 3
5.1 Couche physique du réseau .3
5.2 Support physique .3
5.3 Circuit de terminaison .4
5.3.1 Segment de réseau à quatre conducteurs torsadés .4
5.3.2 Segment de réseau de la couche physique à paires torsadées .4
5.4 Résistance et capacité .6
5.4.1 Résistance interne (R ), capacité interne (C ) .6
in in
5.4.2 Résistance interne différentielle (R ), capacité interne différentielle (C ) .7
diff diff
5.4.3 Terminaison faible pour tronçons de ligne .7
5.5 Exigences de durée d’un bit .7
5.6 Paramètres en courant alternatif .8
6 Exigences de segment de réseau . 8
6.1 Segment de réseau à quatre conducteurs torsadés .8
6.2 Segment de réseau TPPL .8
7 Exigences électriques . 8
7.1 Gammes de service électriques .8
7.1.1 Exigences générales .8
7.1.2 Tensions d’UCE en courant continu .9
7.1.3 Paramètres de l’alimentation électrique en courant continu .9
7.1.4 Tensions du bus (tensions de service) . 12
7.2 Paramètres du support physique . . 12
7.2.1 Câble à quatre conducteurs torsadés non blindé. 12
7.2.2 Paire torsadée non blindée . 13
7.3 Topologie des couches physiques à quatre conducteurs torsadés .14
7.3.1 Généralités .14
7.3.2 Connexion d’une UCE à TBC_PWR et TBC_RTN . 15
7.3.3 Alimentation de TBC_PWR et de TBC_RTN .16
7.4 Topologie de la couche physique à paires torsadées .16
7.4.1 Spécifications générales .16
7.4.2 Tronçon de ligne unique .16
7.4.3 Tronçon de ligne composé . .16
7.4.4 Jonction de fils multiple .17
7.5 Paramètres du circuit de polarisation de terminaison (TBC) .18
7.6 Paramètres de circuit de terminaison .19
7.7 Connecteurs . 20
7.7.1 Généralités . 20
7.7.2 Connecteur d’extension de bus .21
7.7.3 Connecteur côté tracteur pour l’outil (IBBC) . 23
7.7.4 Connecteur cabine .31
7.7.5 Connecteur de diagnostic . 39
8 Plan d’essai de la conformité .44
8.1 Exigences générales . 44
8.2 Résistance interne .45
8.3 Résistance interne différentielle . 46
8.4 Seuil d’entrée récessif d’une UCE . 46

iii
8.5 Seuil d’entrée dominant d’une UCE .47
8.6 Temps de retard interne d’une UCE .47
8.7 Décharge électrostatique . 48
9 Erreurs de bus et confinement des défaillances .49
9.1 Généralités . 49
9.2 Déconnexion du réseau . 49
9.3 Perte de puissance du nœud ou perte de la masse . 49
9.4 Réaction aux perturbations de l’alimentation électrique . 49
9.5 Rupture du réseau lors de la connexion, de la déconnexion ou de la mise sous tension . 49
9.6 Coupures et courts-circuits . 50
Annexe A (informative) Contrôleur de protocole: synchronisation et dénomination .54
Annexe B (informative) Exemples de circuits de couche physique .57
Annexe C (informative) Connecteur d’UCE facultatif sur tronçon de ligne .63
Bibliographie .65

iv
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes nationaux
de normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est en général
confiée aux comités techniques de l'ISO. Chaque comité membre intéressé par une étude a le droit de faire
partie du comité technique créé à cet effet. Les organisations internationales, gouvernementales et non
gouvernementales, en liaison avec l'ISO participent également aux travaux. L'ISO collabore étroitement avec
la Commission électrotechnique internationale (IEC) en ce qui concerne la normalisation électrotechnique.
Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont
décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier, de prendre note des différents
critères d'approbation requis pour les différents types de documents ISO. Le présent document a
été rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2 (voir
www.iso.org/directives).
L’ISO attire l’attention sur le fait que la mise en application du présent document peut entraîner l’utilisation
d’un ou de plusieurs brevets. L’ISO ne prend pas position quant à la preuve, à la validité et à l’applicabilité de
tout droit de propriété revendiqué à cet égard. À la date de publication du présent document, l’ISO n'avait pas
reçu notification qu’un ou plusieurs brevets pouvaient être nécessaires à sa mise en application. Toutefois,
il y a lieu d’avertir les responsables de la mise en application du présent document que des informations
plus récentes sont susceptibles de figurer dans la base de données de brevets, disponible à l'adresse
www.iso.org/brevets. L’ISO ne saurait être tenue pour responsable de ne pas avoir identifié tout ou partie de
tels droits de propriété.
Les appellations commerciales éventuellement mentionnées dans le présent document sont données pour
information, par souci de commodité, à l’intention des utilisateurs et ne sauraient constituer un engagement.
Pour une explication de la nature volontaire des normes, la signification des termes et expressions
spécifiques de l'ISO liés à l'évaluation de la conformité, ou pour toute information au sujet de l'adhésion de
l'ISO aux principes de l’Organisation mondiale du commerce (OMC) concernant les obstacles techniques au
commerce (OTC), voir www.iso.org/avant-propos.
Le présent document a été élaboré par le comité technique ISO/TC 23, Tracteurs et matériels agricoles et
forestiers, sous-comité SC 19, Électronique en agriculture.
Cette quatrième édition annule et remplace la troisième édition (ISO 11783-2:2019), qui a fait l’objet d’une
révision technique.
Les principales modifications sont les suivantes:
— séparation des exigences applicables aux concepteurs d'UCE et aux concepteurs de systèmes;
— mise à jour des exigences électriques pour refléter l’état de l’art actuel;
— restructuration et rationalisation du document.
Une liste de toutes les parties de la série ISO 11783 se trouve sur le site web de l’ISO.
Il convient que l’utilisateur adresse tout retour d’information ou toute question concernant le présent
document à l’organisme national de normalisation de son pays. Une liste exhaustive desdits organismes se
trouve à l’adresse www.iso.org/fr/members.html.

v
Introduction
La série de normes ISO 11783 spécifie un système de communications destiné aux matériels agricoles,
fondé sur le protocole CAN de l’ISO 11898-1. La série SAE J1939 1), sur laquelle certaines parties de la série
ISO 11783 se fonde, a été élaborée conjointement pour une utilisation dans des applications de camions et de
bus, de construction et d’agriculture. Des documents communs ont été élaborés pour permettre l’utilisation,
sur des matériels agricoles et forestiers, d’unités électroniques conformes aux spécifications SAE J1939
relatives aux camions et aux bus, sans que des modifications majeures soient nécessaires. Des informations
générales sur la série ISO 11783 peuvent être trouvées dans l’ISO 11783-1.
L'objectif de la série ISO 11783 est de fournir un système ouvert et interconnecté pour les systèmes
électroniques embarqués. Elle vise à permettre aux unités de commande électroniques (UCE) de
communiquer entre elles, en fournissant un système normalisé.

vi
PROJET FINAL Norme internationale ISO/FDIS 11783-2:2026(fr)
Tracteurs et matériels agricoles et forestiers — Réseaux de
commande et de communication de données en série —
Partie 2:
Couche physique
IMPORTANT — Le présent document contient des couleurs qui sont considérées comme étant utiles
à la bonne compréhension du document. Il convient ainsi que les utilisateurs impriment le présent
document en utilisant une imprimante couleurs.
1 Domaine d’application
Le présent document spécifie l'interface des dispositifs utilisant la sous-couche de raccordement au support
physique (PMA) basée sur un CAN HS (haute vitesse), telle que définie dans l'ISO 11783-2, et la sous-couche
de codage physique (PCS), telle que définie dans l'ISO 11898-1. Il spécifie deux sous-couches dépendantes du
support physique:
a) câble à quatre conducteurs torsadés non blindé, et
b) câble à paires torsadées non blindé.
NOTE Sauf spécification contraire, les exigences sont valables aussi bien pour la couche physique à quatre
conducteurs torsadés (TQPL) que pour la couche physique à paires torsadées (TPPL).
2 Références normatives
Les documents suivants sont cités dans le texte de sorte qu’ils constituent, pour tout ou partie de leur
contenu, des exigences du présent document. Pour les références datées, seule l’édition citée s’applique. Pour
les références non datées, la dernière édition de la publication à laquelle il est fait référence s’applique (y
compris tous les amendements).
ISO 1724, Véhicules routiers — Connecteurs pour liaisons électriques entre véhicules tracteurs et véhicules
tractés — Connecteur à 7 contacts de type 12 N (normal) pour les véhicules à tension nominale de 12 V
ISO 11783-1, Tracteurs et matériels agricoles et forestiers — Réseaux de commande et de communication
de données en série — Partie 1: Système normalisé général pour les communications de données avec les
équipements mobiles
ISO 11898-1:2024, Véhicules routiers — Gestionnaire de réseau de communication (CAN) — Partie 1: Couche
liaison de données et sous-couche de codage physique
ISO 11898-2:2026, Véhicules routiers — Gestionnaire de réseau de communication (CAN) — Partie 2: Sous-
couche de l’unité d'accès au support à haute vitesse (PMA)
S A E J1939 -15: 2018 , Physical Layer, 250 Kbps, Un-Shielded Twisted Pair (UTP)
3 Termes et définitions
Pour les besoins du présent document, les termes et définitions donnés dans l’ISO 11783-1 ainsi que les
suivants, s’appliquent.
L’ISO et l’IEC tiennent à jour des bases de données terminologiques destinées à être utilisées en normalisation,
consultables aux adresses suivantes:
— ISO Online browsing platform: disponible à l’adresse https:// www .iso .org/ obp
— IEC Electropedia: disponible à l’adresse https:// www .electropedia .org/
3.1
UCE du type I
unité de commande électronique sans terminaison interne
3.2
UCE du type I FAIBLE
unité de commande électronique avec terminaison à résistance divisée et couplée au centre à UCE_GND par
un condensateur et qui est utilisée uniquement pour des tronçons de ligne (voir 5.4.3)
3.3
UCE du type II
unité de commande électronique avec circuit de terminaison interne
3.4
temps de retard interne
somme des retards asynchrones qui surviennent au cours de la transmission et de la réception à l’intérieur
de l’UCE, par rapport à l’unité logique de synchronisation de bits de l’équipement CAN (voir A.2)
3.5
couche physique à paires torsadées
TPPL
couche réseau à câble à paires torsadées non blindé, pour une vitesse de transfert de 250 kbit/s, destinée à
être utilisée comme alternative à la couche physique à quatre conducteurs torsadés et qui est rétrocompatible
avec les machines basées sur une couche physique à quatre conducteurs torsadés
3.6
machine
tracteur forestier ou agricole ou outil porté, semi-porté, traîné ou automoteur
3.7
segment de réseau
réseau CAN unique utilisant une configuration de topologie linéaire avec des tronçons de ligne
3.8
nœud
ensemble, relié à un réseau de communication, capable de communiquer au travers du réseau conformément
à une spécification de protocole de communication
Note 1 à l'article: Un nœud peut se trouver dans l’un des quatre états suivants: intégration, inactif, récepteur ou
émetteur.
Note 2 à l'article: Un nœud fonctionnant dans un gestionnaire de réseau de communication (CAN) est appelé un nœud
CAN.
[SOURCE: ISO 11898-1:2024, 3.39, modifiée — la définition a été modifiée afin d'exclure des informations
supplémentaires.]
3.9
couche physique à quatre conducteurs torsadés
TQPL
couche réseau à câble à quatre conducteurs torsadés non blindé, pour une vitesse de transfert de 250 kbit/s

4 Abréviations
IBBC connecteur côté tracteur pour l’outil (femelle)
IBBP connecteur côté outil pour le tracteur
CAN gestionnaire de réseau de communication
PMA raccordement au support physique
PCS sous-couche de codage physique
UCE unité de commande électronique
PWR alimentation
GND masse
CC courant continu
MDI interface dépendante du support
CA courant alternatif
TBC circuit de polarisation de terminaison
TBC_GND masse du circuit de polarisation de terminaison
TBC_RTN retour du circuit de polarisation de terminaison
5 Exigences générales
5.1 Couche physique du réseau
La sous-couche de codage physique doit être conforme aux exigences CAN CC telles que données dans
l’ISO 11898-1:2024, Article 7; elle est mise en œuvre dans des unités de contrôleur de protocole CAN en
utilisant un codage sans retour à zéro (NRZ). La sous-couche de raccordement au support physique (PMA)
doit être conforme aux exigences pour des entités PMA haute vitesse supportant des débits jusqu’à 1 Mbit/s
telles que données dans l’ISO 11898-2:2026, Tableau 15 en particulier; elle est mise en œuvre dans des unités
d’émetteur-récepteur CAN haute vitesse (HS).
La sous-couche dépendante du support physique (PMD) est spécifiée dans les paragraphes suivants. Cela
inclut des exigences pour le concepteur d’UCE: 5.4, 5.5, 7.1.2, 7.1.3.5, 7.1.3.5.
Les exigences pour les concepteurs de réseau sont données dans: 5.2, 5.3, Article 6, 7.1.3.1, 7.1.3.2, 7.1.3.3,
7.1.3.4, 7.1.4, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7.
5.2 Support physique
Le présent document définit deux types de support physique.
a) TQPL: doit être composé de quatre conducteurs dont deux, CAN_H et CAN_L, sont les porteurs des
signaux de communication électriques. Les broches correspondantes du connecteur UCE portent les
mêmes noms, respectivement CAN_H et CAN_L. Les deux autres conducteurs, désignés TBC_PWR et
TBC_RTN, fournissent l’électricité aux circuits de polarisation de terminaison (TBC) du segment de
réseau.
b) TPPL: doit être composé d’un câble à paires torsadées tel que décrit dans la SAE J1939-15. Les
conducteurs, CAN_H et CAN_L, sont les porteurs de la MDI telle que spécifiée dans l’ISO 11898-2. Les
broches correspondantes du connecteur UCE portent les mêmes noms, respectivement CAN_H et CAN_L.

5.3 Circuit de terminaison
5.3.1 Segment de réseau à quatre conducteurs torsadés
Les lignes de signaux de bus d'un segment de réseau à quatre conducteurs torsadés doivent posséder à
chaque extrémité une terminaison électrique qui revêt la forme d’un circuit de polarisation de terminaison.
L’activation d’un émetteur-récepteur de nœud induit un flux de courant (I) qui est soit dissipé par la
terminaison CAN_H, soit alimenté par la terminaison CAN_L. Ce circuit de polarisation de terminaison doit
être monté à l’extérieur de l’enceinte des UCE afin d’assurer la polarisation du bus et la terminaison des
lignes lorsque les UCE sont déconnectées (voir la Figure 1).
Légende
1 UCE no 1
2 UCE no n
3 circuit de polarisation de terminaison (TBC)
4 alimentation de TBC_PWR et de TBC_RTN
5 câble à quatre conducteurs torsadés
Figure 1 — Diagramme fonctionnel de la couche physique
5.3.2 Segment de réseau de la couche physique à paires torsadées
Les lignes de signaux de bus d'un segment de réseau TPPL doivent posséder à chaque extrémité une
terminaison électrique au moyen d'une résistance de terminaison R (voir la Figure 2) ou d'un circuit passif
t
de terminaison à résistance divisée utilisant deux résistances R et R , couplées à la masse par un
tCAN_H tCAN_L
condensateur C (voir la Figure 4). Les exigences électriques relatives aux deux solutions sont définies au
split
7.6.
La Figure 3 présente la terminaison d'un segment de réseau utilisant des UCE du type II.
Il convient que le concepteur du système veille à ce que le segment de réseau possède une terminaison à
une extrémité ou aux deux extrémités. Les UCE du type II doivent être marquées. Une UCE du type II doit
uniquement être utilisée à une extrémité ou aux deux extrémités d’un bus, même lorsque la machine est
reliée à une autre machine par un IBBC. Les UCE du type II doivent être uniquement alimentées par UCE_
PWR/UCE_GND.
Légende
1 UCE du type I no 1
2 UCE du type I no n
3 paire torsadée non blindée
4 résistances de terminaison R
t
Figure 2 — Circuit de terminaison passive TPPL utilisant des résistances uniques à chaque
extrémité du segment de réseau
Légende
1 UCE du type I
2 UCE du type II avec R interne
t
3 paire torsadée non blindée
Figure 3 — Circuit de terminaison passive TPPL (une extrémité) utilisant une UCE du type II en tant
que terminaison
Légende
1 UCE du type II ou terminaison de bus passive
2 résistance R
tCAN_H
3 résistance R
tCAN_L
4 condensateur de couplage C
split
Figure 4 — Circuit de terminaison passive TPPL (une extrémité) utilisant une terminaison à
résistance divisée
5.4 Résistance et capacité
5.4.1 Résistance interne (R ), capacité interne (C )
in in
La résistance interne, R , d’une UCE est égale à la résistance observée à l’état récessif entre CAN_H ou
in
CAN_L et la masse (UCE_GND), lorsque l’UCE est déconnectée de CAN_H et CAN_L. Les mesurages doivent
être effectués avec et sans alimentation de l’UCE et la valeur minimale doit être utilisée pour confirmer la
conformité.
La capacité interne, C , d’une UCE est égale à la capacité interne observée à l’état récessif entre CAN_H ou
in
CAN_L et UCE_GND, lorsque l’UCE est déconnectée de CAN_H et CAN_L. Les mesurages doivent être effectués
avec et sans alimentation de l’UCE et la valeur maximale doit être utilisée pour confirmer la conformité.
La Figure 5 montre le circuit équivalent d’une résistance interne et d’une capacité interne d’une UCE.
Légende
1 UCE
2 résistance interne R
in
3 capacité interne C
in
Figure 5 — Résistance et capacité internes d’une UCE à l’état récessif

5.4.2 Résistance interne différentielle (R ), capacité interne différentielle (C )
diff diff
La résistance interne différentielle, R , est égale à la résistance observée à l’état récessif entre CAN_H et
diff
CAN_L, lorsque l’UCE est déconnectée de CAN_H et CAN_L. Les mesurages doivent être effectués avec et sans
alimentation de l’UCE et la valeur minimale doit être utilisée pour confirmer la conformité.
La capacité interne différentielle, C , est égale à la capacité observée à l’état récessif entre CAN_H et CAN_L,
diff
lorsque l’UCE est déconnectée de CAN_H et CAN_L (voir la Figure 6). Les mesurages doivent être effectués
avec et sans alimentation de l’UCE et la valeur maximale doit être utilisée pour confirmer la conformité.
La Figure 6 montre le circuit équivalent d’une résistance interne différentielle et d’une capacité interne
différentielle d’une UCE.
Légende
1 UCE
2 capacité interne différentielle C
diff
3 résistance interne différentielle R
diff
Figure 6 — Résistance et capacité internes différentielles d’une UCE à l’état récessif
5.4.3 Terminaison faible pour tronçons de ligne
Pour une plus grande immunité et de meilleures performances en CEM, les nœuds de la TPPL qui sont
connectés au bus peuvent être réalisés en utilisant l’UCE du type I FAIBLE équipée d'un circuit à terminaison
à résistance divisée. Dans ce cas, la terminaison à résistance divisée doit être réalisée à l'aide de deux
résistances de 750 Ω couplées à une UCE_GND par l'intermédiaire d'un condensateur de 47 nF. Le nombre
total d’UCE du type I FAIBLE utilisé sur un seul segment de réseau ne doit pas dépasser trois unités.
Dans le cas où une UCE du type I FAIBLE est alimentée par les lignes PWR/GND, la terminaison à résistance
divisée doit être couplée avec la masse (GND).
5.5 Exigences de durée d’un bit
Les fonctions de gestion de bus exécutées pendant cet intervalle, telles que la synchronisation du
contrôleur de protocole, la compensation du délai de transmission réseau et le positionnement du point
d’échantillonnage, sont spécifiées par la logique de synchronisation de bits programmable du contrôleur de
protocole CAN conforme à l'ISO 11898-1.
Le débit doit être 250 kbit/s, ce qui se traduit par une durée d’un bit de 4 µs.
Par ailleurs, les paramètres suivants doivent être configurés:
— la méthode à un seul point d’échantillonnage telle que définie dans l’ISO 11898-1;
— le point d’échantillonnage à 80 % ± 3 % de la durée d’un bit.
Pour plus de détails, voir l'Annexe A.

5.6 Paramètres en courant alternatif
Le Tableau 1 spécifie les paramètres en courant alternatif pour une UCE déconnectée du bus. Les paramètres
de synchronisation s’appliquent également pour une UCE connectée à un segment de réseau.
Tableau 1 — Paramètres d’un nœud déconnecté du bus, en courant alternatif
Paramètre Symbole Min. Nom. Max. Unité Condition
Durée d’un bit t 3,998 4,000 4,002 µs 250 kbit/s
B
Mesurée de 10 % à 90 % de la
Durée de transition t — — 500 ns
T
tension à l’état dominant
Temps de retard interne T 0,0 — 0,9 µs Aucune
UCE
Capacité interne avec sortie asy-
C 0 — 200 pF 1 MHz
in
métrique
Capacité interne différentielle C 0 — 100 pF 1 MHz
diff
CMR 40 — — dB Du courant continu à 50 kHz
5 MHz pouvant décroître de
Réjection mode commun
CMR 10 — — dB façon linéaire entre 50 kHz et
5 MHz
5 MHz
6 Exigences de segment de réseau
6.1 Segment de réseau à quatre conducteurs torsadés
Tout segment de réseau à quatre conducteurs torsadés linéaire doit posséder à chaque extrémité une
terminaison de la forme d’un circuit de polarisation de terminaison (TBC) (voir la Figure 1 et 7.5). Le
circuit de polarisation de terminaison assure la polarisation électrique et la terminaison de mode commun
nécessaires à la suppression des réflexions.
Le segment de réseau est récessif lorsque les émetteurs de tous les nœuds sont hors tension, avec la tension
moyenne générée par les circuits de polarisation de terminaison. Un niveau de tension dominant est transmis
aux lignes de signaux du bus dès lors que l’émetteur d’un nœud au moins est sous tension. Cela induit un
courant à chaque extrémité des circuits de polarisation de terminaison, ce qui produit en conséquence une
tension différentielle entre les lignes CAN_H et CAN_L.
6.2 Segment de réseau TPPL
Tout segment de réseau linéaire de la TPPL doit posséder à chaque extrémité un circuit de terminaison
passive (voir 5.3.2) pour supprimer les réflexions.
Le segment de réseau est récessif lorsque les émetteurs de tous les nœuds sont hors tension. Un bit dominant
est transmis aux lignes de signaux du bus dès lors que l’émetteur d’un nœud au moins est sous tension de
sorte qu’une tension différentielle est produite entre les lignes CAN_H et CAN_L.
7 Exigences électriques
7.1 Gammes de service électriques
7.1.1 Exigences générales
Les UCE doivent être conformes aux paramètres spécifiés dans les Tableau 1, Tableau 2, Tableau 7, Tableau 8,
Tableau 9 et Tableau 10 dans l’ensemble de leur gamme de températures de service.

7.1.2 Tensions d’UCE en courant continu
Le Tableau 2 spécifie les tensions absolues maximales en courant continu qui peuvent être appliquées sur les
lignes de signaux du bus sans endommager les nœuds.
Tableau 2 — Limites de V et de V d’une UCE déconnectée du bus
CAN_H CAN_L
Paramètre Symbole Minimum Maximum Unité Conditions
V
CAN_H
Tension max. en continu −16,0 +16,0 V Tension nominale d’alimentation 12 V
V
CAN_L
7.1.3 Paramètres de l’alimentation électrique en courant continu
7.1.3.1 Tensions de l’alimentation électrique de l’architecture en courant continu
Le Tableau 3 spécifie les limites des gammes de service de l’alimentation électrique lorsque la tension
d’alimentation nominale est de 12 V lors de la prise en compte de l’architecture d'alimentation de système.
Tableau 3 — Limites des gammes de service de l’alimentation électrique
Paramètre Symbole Minimum Maximum Unité Conditions
V
Gamme de tensions de ser- Tension nominale d’alimentation
PWR
+10,0 +16,0 V
vice 12 V
V
UCE_PWR
7.1.3.2 Intensités minimales du courant de l’alimentation électrique de l’architecture
Le Tableau 4 spécifie l’intensité minimale du courant d’alimentation des lignes UCE_PWR et PWR lors de la
prise en compte de l’architecture d'alimentation de système.
Tableau 4 — Intensités minimales du courant de l’alimentation électrique
Paramètre Symbole Minimum Unité
I 50 A
PWR
Intensité du courant d’alimentation
I 15 A
UCE_PWR
7.1.3.3 Exigences pour la tension en courant continu fournie par le tracteur aux bornes de l’IBBC
Sur le tracteur, l’alimentation électrique est fournie par l’alimentation 12 V et le système d’alternateur aux
différentes charges électriques situées sur le tracteur et l’outil. Pour s’assurer que le tracteur peut fournir
une alimentation électrique adéquate à l’outil, les exigences de tension spécifiées dans les Tableau 5 et
Tableau 6 s’appliquent aux bornes d’alimentation électrique IBBC/TPPL-BC.
L’intensité minimale du courant d’alimentation des lignes de bus UCE_PWR/UCE_GND de l’outil du tracteur
doit être de 15 A dans les conditions spécifiées dans le Tableau 5.

Tableau 5 — Limites d’UCE_PWR aux bornes IBBC/TPPL-BC du tracteur
Paramètre Symbole Min. Max. Unité
Tension des lignes
V 10,5 16,0 V
ECU_DIFF
d’alimentation d’UCE
Conditions pour le mesurage:
—  V = V - V
UCE_DIFF UCE_PWR UCE_GND
—  mesurée aux bornes IBBC/TPPL-BC du tracteur
—  charge électrique de 15 A CC.
−1
—  régime moteur dans sa gamme de fonctionnement normale min (défini par le constructeur)
—  charges électriques du tracteur sous tension (éclairage, ventilateurs, etc.)
—  gamme de températures de service: de −30 °C à 85 °C
L’intensité minimale du courant d’alimentation du circuit de bus PWR/GND de l’outil du tracteur doit être de
50 A dans les conditions spécifiées dans le Tableau 6.
Tableau 6 — Limites de PWR aux bornes IBBC/TPPL-BC du tracteur
Tension des lignes d’alimentation Min. Max. Unité
V – V 10,5 16,0 V
PWR GND
Conditions pour le mesurage:
—  mesurée aux bornes IBBC/TPPL-BC du tracteur
—  charge électrique de 50 A CC.
−1
—  régime moteur dans sa gamme de fonctionnement normale min (défini par le constructeur)
—  charges électriques du tracteur sous tension (éclairage, ventilateurs, etc.)
—  gamme de températures de service: de −30 °C à 85 °C
L’intensité maximale combinée simultanée prélevée par un outil aux bornes de l’IBBC ne doit pas dépasser
55 A (courant continu).
NOTE Des intensités combinées plus élevées entraînent de hautes températures qui peuvent endommager le
connecteur ou les broches.
7.1.3.4 Exigences concernant la chute de tension CC sur les outils
Sur un outil, l’alimentation électrique est fournie par les lignes PWR et UCE_PWR aux bornes de l’IBBC.
L’outil peut être pourvu d’un socle IBBC à l’arrière pour permettre la connexion en série d’outils
supplémentaires qui agissent comme des charges électriques.
En cas de connexion en série, si les chutes de tension dues à la résistance des conducteurs d’alimentation et
de retour sur un outil sont trop élevées, l’outil suivant peut ne pas disposer d’une alimentation électrique
suffisante pour fonctionner correctement. Pour éviter une telle situation et s’assurer qu’un outil peut
alimenter correctement en énergie électrique le suivant, la chute de tension maximale admise sur un outil
doit être conforme au Tableau 7 et les intensités minimales des courants d’alimentation fournis aux outils
doivent être conformes au 7.1.3.2.

Tableau 7 — Chute de tension maximale admise dans un outil
Tension des lignes d’alimentation Min. Max. Unité
Chute de tension d’outil dans des
— 1,5 V
a
lignes UCE_PWR/UCE_GND
Chute de tension d’outil dans des
— 1,5 V
b
lignes PWR/GND
a
15 A disponibles aux bornes arrière IBBC d’outil
b
50 A disponibles aux bornes arrière IBBC d’outil
Conditions pour le mesurage (voir la Figure 7):
—  mesurée entre la fiche de l’outil et les bornes arrière IBBC d’outil
—  toutes les charges sur l’outil soumis à l’essai doivent être déconnectées
—  1,5 V est la chute de tension totale des deux trajets (alimentation et retour)
—  gamme de températures de service: de −30 °C à 85 °C

Figure 7 — Mesurage de la chute de tension
7.1.3.5 UCE déconnectée du bus
Les paramètres pour courant continu pour l’état récessif de l’interface CAN d’une UCE alimentée déconnectée
du bus sont spécifiés dans le Tableau 8.
Tableau 8 — Paramètres pour courant continu d’UCE déconnectées du bus à l’état récessif
Paramètre Symbole Min. Nom. Max. Unité
V
CAN_H
Comportement de la tension de sortie du bus 2,0 2,5 3,0 V
V
CAN_L
Comportement de la tension de sortie diffé- —
V −1 200 50 mV
diff
rentielle
Résistance interne différentielle (UCE du type I —
R 2 100 kΩ
g diff
seulement)
g
Résistance interne (UCE du type I seulement) R 5 — 50 kΩ
in
Adaptation résistance interne — −5 — 5 %
Tension différentielle d’entrée détectée —
V −1,0 0,5 V
diff_IR
comme récessive
Les paramètres pour courant continu pour l’état dominant de l’interface CAN d’une UCE déconnectée du bus
sont spécifiés dans le Tableau 9.

Tableau 9 — Paramètres pour courant continu d’UCE déconnectées du bus à l’état dominant
Paramètre Symbole Min. Max. Unité
V 2,75 5,0
CAN_H
Tension du bus
V 0,0 2,25
CAN_L
V
Tension de sortie différentielle V 1,5 3,0
diff_OD
Tension différentielle détectée comme domi-
V 1,0 5,0
diff_ID
nante
7.1.3.6 UCE connectée au bus
Les paramètres pour courant continu pour l’état récessif de l’interface CAN d’une UCE connectée à un
segment de réseau et à d’autres UCE sont spécifiés dans le Tableau 10.
Tableau 10 — Paramètres pour courant continu de tension du bus, avec les UCE connectées au bus à
l’état récessif, sans erreur
Paramètre Symbole Min. Max. Unité Conditions
V
CAN_H
Tension du bus 0,1 4,5 V Mesurée par rapport à la masse de chaque UCE
V
CAN_L
Tension différentielle
V −1 200 50 mV Mesurée à chaque UCE connectée à CAN H et CAN L
diff_R
du bus
Les paramètres pour courant continu pour l’état dominant de l’interface CAN d’une UCE connectée à un
segment de réseau et à d’autres UCE sont spécifiés dans le Tableau 11.
Tableau 11 — Paramètres pour courant continu de tension du bus, avec les UCE connectées au bus à
l’état dominant, sans erreur
Paramètre Symbole Min. Max. Unité Conditions
V — 7,0
CAN_H
Tension du bus V Mesurée par rapport à la masse de chaque UCE
V −2,0 —
CAN_L
Mesurée à chaque UCE connectée aux lignes de
3,0
Tension différentielle du
signaux du bus
V 1,2 V
diff
bus
5,0 Lors de l’arbitrage
7.1.4 Tensions du bus (tensions de service)
Les paramètres de tension du bus spécifiés dans le Tableau 11 sont à utiliser lorsque toutes les UCE
(de 2 à
...