IEC 62783-2:2019

IEC 62783-2 ®
Edition 1.0 2019-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Twinax cables for digital communications –
Part 2: Family specification – Cable for Ethernet-over-twinax physical interfaces

Câbles twinax pour transmissions numériques –
Partie 2: Spécification de famille – Câble pour interfaces physiques Ethernet sur
twinax
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IEC 62783-2 ®
Edition 1.0 2019-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Twinax cables for digital communications –

Part 2: Family specification – Cable for Ethernet-over-twinax physical interfaces

Câbles twinax pour transmissions numériques –

Partie 2: Spécification de famille – Câble pour interfaces physiques Ethernet sur

twinax
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.120.20 ISBN 978-2-8322-6160-6

– 2 – IEC 62783-2:2019 © IEC 2019
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Requirements for cables construction . 8
4.1 General remarks . 8
4.2 Cable construction . 8
4.2.1 General . 8
4.2.2 Conductor . 8
4.2.3 Insulation . 8
4.2.4 Colour code . 8
4.2.5 Drain wire . 8
4.2.6 Screening of cable assembly element . 8
4.2.7 Cable make-up . 8
4.2.8 Screening of the cable core . 8
4.2.9 Sheath . 9
4.2.10 Colour of sheath . 9
4.2.11 Identification . 9
4.2.12 Finished cable . 9
5 Requirements and test methods . 9
5.1 General remarks . 9
5.2 Electrical tests . 10
5.2.1 Conductor resistance . 10
5.2.2 Resistance unbalance. 10
5.2.3 Dielectric strength . 10
5.2.4 Insulation resistance . 10
5.2.5 Mutual capacitance . 10
5.2.6 Surface transfer impedance . 10
5.3 Transmission requirements and tests . 10
5.3.1 General . 10
5.3.2 Characteristic impedance . 10
5.3.3 Return loss . 10
5.3.4 Attenuation . 10
5.3.5 Propagation delay, inter-element delay skew, and intra-element delay
skew . 10
5.3.6 Near-end crosstalk (NEXT) . 10
5.3.7 Attenuation to crosstalk ratio far-end (ACR-F) . 11
5.3.8 Transverse conversion loss (TCL) . 11
5.3.9 Equal level transverse conversion transfer loss (ELTCTL) . 11
5.3.10 Screening attenuation . 11
5.3.11 Coupling attenuation . 11
5.4 Mechanical and dimensional requirements and test methods . 11
5.4.1 General . 11
5.4.2 Measurement of dimensions . 11
5.4.3 Elongation at break of the conductor. 11
5.4.4 Tensile strength of the insulation . 11

5.4.5 Elongation at break of the sheath . 11
5.4.6 Tensile strength of the sheath . 11
5.4.7 Crush test of the cable . 11
5.4.8 Impact test of the cable . 11
5.4.9 Repeated bending of the cable . 12
5.4.10 Tensile performance of the cable . 12
5.5 Environmental tests . 12
5.5.1 Shrinkage of the insulation . 12
5.5.2 Wrapping test of the insulation after thermal ageing . 12
5.5.3 Bending test of the insulation at low temperature . 12
5.5.4 Tensile strength and elongation of the sheath after ageing . 12
5.5.5 Sheath pressure test at high temperature . 12
5.5.6 Cold bend test of the cable . 12
5.5.7 Heat shock test . 12
5.5.8 Flame propagation characteristics of a single cable . 12
5.5.9 Flame propagation characteristics of bunched cables . 12
5.5.10 Smoke generation . 12
Bibliography . 13

Table 1 – Supported IEEE 802.3 Ethernet-over-twinax implementations, configurations . 8
Table 2 – Supported IEEE 802.3 Ethernet-over-twinax implementations, transmission
requirements . 9

– 4 – IEC 62783-2:2019 © IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
TWINAX CABLES FOR DIGITAL COMMUNICATIONS –

Part 2: Family specification – Cable for Ethernet-over-twinax
physical interfaces
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC
Publication(s)"). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
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Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62783-2 has been prepared by subcommittee 46C: Wires and
symmetric cables, of IEC technical committee 46: Cables, wires, waveguides, RF connectors,
RF and microwave passive components and accessories.
The text of this International Standard is based on the following documents:
FDIS Report on voting
46C/1103/FDIS 46C/1108/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

This International Standard is to be used in conjunction with the first edition of
IEC 62783-1:— .
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
___________
Under preparation. Stage at the time of publication: IEC FDIS 62783-1:2018.

– 6 – IEC 62783-2:2019 © IEC 2019
INTRODUCTION
This International Standard is a family specification. It constitutes Part 2 of the IEC 62783
series, which covers specific characteristics of twinax cables.
This document describes cables that are in compliance with the generic twinax cable
requirements given in IEC 62783-1.
The family of twinax cables covered in this document are specifically intended for
interconnection of Ethernet links over twinax cables, which are implemented using twinax link
segments in accordance with IEEE Std 802.3™ Ethernet physical interfaces, for example,
10GBASE-CX4.
TWINAX CABLES FOR DIGITAL COMMUNICATIONS –

Part 2: Family specification – Cable for Ethernet-over-twinax
physical interfaces
1 Scope
This part of IEC 62783 covers indoor cables and specifies the definitions and requirements of
twin-axial cables used in digital communication systems.
This document, which is a family specification, gives additional requirements for twinax cables
for use in IEEE Std 802.3 Ethernet physical interfaces.
This document gives requirements and transmission characteristics for single twinax elements
as well as for multiple twinax elements within the same sheath, i.e. "twinax cable".
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.
IEC TR 61156-1-2 :2009, Multicore and symmetrical pair/quad cables for digital
communications – Part 1-2: Electrical transmission characteristics and test methods of
symmetrical pair/quad cables
IEC TR 61156-1-2:2009/AMD1:2014
IEC 62783-1:— , Twinax cables for digital communications – Part 1: Generic specification
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 62783-1 apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
___________
A consolidated version of this publication exists, comprising IEC TR 61156-1-2:2009 and
IEC TR 61156-1-2:2009/AMD 1:2014.
Under preparation. Stage at the time of publication: IEC FDIS 62783-1:2018.

– 8 – IEC 62783-2:2019 © IEC 2019
4 Requirements for cables construction
4.1 General remarks
These twinax cables' characteristic impedance is 100 Ω. These twinax cable configurations
range from 2 to 20 twinax elements, depending on the specific Ethernet implementation.
Conductor size may range from 0,2 mm to 0,6 mm (32 AWG to 22 AWG).
4.2 Cable construction
4.2.1 General
The cable element and the cable shall be constructed accordingly to conform to IEC 62783-1
and to this document.
4.2.2 Conductor
The conductor shall conform to IEC 62783-1 and to the detail specifications.
4.2.3 Insulation
The insulation shall conform to IEC 62783-1 and to the detail specifications.
4.2.4 Colour code
The colour code shall conform to the detail specifications.
4.2.5 Drain wire
The drain wire shall conform to IEC 62783-1 and to the detail specifications.
4.2.6 Screening of cable assembly element
The cable element screen shall conform to IEC 62783-1 and to the detail specifications.
4.2.7 Cable make-up
The twinax cable consisting of 2 to 20 twinax elements as per Table 1, shall conform to
IEC 62783-1 and to the detail specifications.
Table 1 – Supported IEEE 802.3 Ethernet-over-twinax implementations, configurations
Application IEEE 802.3:2015 Nominal Number Long Short
(reference) frequency of lanes reach reach
m m
1000BASE-CX Clause 39 625 MHz 2 10 5
10GBASE-CX4 Clause 54 1,562 5 GHz 8 7 3
100GBASE-CR10 Clause 85 5,156 25 GHz 20 3 1
40GBASE-CR4 Clause 85 5,156 25 GHz 8 3 1
100GBASE-CR4 Clause 92 12,890 6 GHz 8 3 1
a
25GBASE-CR 12,890 6 GHz 2 3 1
a
Clause 110 to be published in IEEE 802.3:2018.

4.2.8 Screening of the cable core
The cable core screening shall conform to IEC 62783-1 and to the detail specifications.

4.2.9 Sheath
The finished cable sheath shall conform to IEC 62783-1 and to the detail specifications.
4.2.10 Colour of sheath
The colour of the finished cable sheath may be specified in the detail specifications.
4.2.11 Identification
4.2.11.1 Cable marking
The cable shall be marked as specified in the detail specifications.
4.2.11.2 Labelling
The cable shall be labelled as specified in the detail specifications.
4.2.12 Finished cable
Finished cable shall be packaged as specified in the detail specifications.
5 Requirements and test methods
5.1 General remarks
Unless otherwise specified, all tests and measurements shall conform to IEC 62783-1 and to
the detail specifications.
These transmission requirements given in Table 2 are based on IEEE 802.3
Ethernet-over-twinax link segment requirements, which are given for information.
Table 2 – Supported IEEE 802.3 Ethernet-over-twinax implementations,
transmission requirements
Application IEEE Nominal Frequency IL max. RL min. ACR-F max.
802.3:2015 frequency range (at nominal (at nominal (at nominal
frequency) frequency) frequency)
1000BASE- Clause 39 625 MHz 10 MHz to 8,8 dB See detail See detail
CX 1 GHz specifications specifications
10GBASE- Clause 54 1,562 5 GHz 100 MHz 16,0 dB 12 dB See detail
CX4 to 2 GHz specifications
100GBASE- Clause 85 5,156 25 GHz 50 MHz to 17,04 dB 6,66 dB See detail
CR10, 10 GHz specifications
40GBASE- Clause 85 5,156 25 GHz 50 MHz to 17,04 dB 6,66 dB See detail
CR4 10 GHz specifications
100GBASE- Clause 92 12,890 6 GHz 50 MHz to 22,48 dB 6 dB See detail
CR4 19 GHz specifications
a
25GBASE-CR 12,890 6 GHz 50 MHz to 22,48 dB 6 dB See detail
19 GHz specifications
a
Clause 110 to be published in IEEE 802.3:2018.
NOTE Near-end crosstalk (NEXT) is not specified for this application.

– 10 – IEC 62783-2:2019 © IEC 2019
5.2 Electrical tests
5.2.1 Conductor resistance
The conductor resistance shall conform to IEC 62783-1 and to the detail specifications.
5.2.2 Resistance unbalance
The resistance unbalance shall conform to IEC 62783-1 and to the detail specifications.
5.2.3 Dielectric strength
Dielectric strength shall conform to IEC 62783-1 and to the detail specifications.
5.2.4 Insulation resistance
Insulation resistance shall conform to IEC 62783-1 and to the detail specifications.
5.2.5 Mutual capacitance
Mutual capacitance shall conform to IEC 62783-1 and to the detail specifications.
5.2.6 Surface transfer impedance
Surface transfer impedance of the screen shall conform to IEC 62783-1 and to the detail
specifications.
5.3 Transmission requirements and tests
5.3.1 General
Transmission requirements shall conform to IEC 62783-1 and to the detail specifications, over
the frequency range specified in the detail specifications.
Transmission requirements' conformance is determined in accordance with IEC 62783-1 using
test procedures according to IEC TR 61156-1-2:2009/AMD1:2014.
5.3.2 Characteristic impedance
The nominal characteristic impedance, 100 Ω, shall conform to IEC 62783-1 and to the detail
specifications.
5.3.3 Return loss
The return loss shall conform to IEC 62783-1 and to the detail specifications.
5.3.4 Attenuation
The attenuation shall conform to IEC 62783-1 and to the detail specifications.
5.3.5 Propagation delay, inter-element delay skew, and intra-element delay skew
Propagation delay, inter-element delay skew, and intra-element delay skew shall conform to
IEC 62783-1 and to the detail specifications.
5.3.6 Near-end crosstalk (NEXT)
The near-end crosstalk (NEXT) loss shall conform to IEC 62783-1 and to the detail
specifications.
5.3.7 Attenuation to crosstalk ratio far-end (ACR-F)
The ACR-F loss shall conform to IEC 62783-1 and to the detail specifications.
5.3.8 Transverse conversion loss (TCL)
TCL shall conform to IEC 62783-1 and to the detail specifications.
5.3.9 Equal level transverse conversion transfer loss (ELTCTL)
Transverse conversion transfer loss (TCTL) shall conform to IEC 62783-1 and to the detail
specifications. ELTCTL is derived from TCTL and IL measurements by deducting IL from TCTL.
5.3.10 Screening attenuation
Screening attenuation shall conform to IEC 62783-1 and to the detail specifications.
5.3.11 Coupling attenuation
Coupling attenuation shall conform to IEC 62783-1 and to the detail specifications.
Alternatively, coupling attenuation may be verified by the combination of ELTCTL and
screening attenuation verification.
5.4 Mechanical and dimensional requirements and test methods
5.4.1 General
Mechanical and dimensional requirements shall be as specified in the detail specifications.
5.4.2 Measurement of dimensions
The measurement of dimensions shall conform to IEC 62783-1 and to the detail
specifications.
5.4.3 Elongation at break of the conductor
The elongation at break of the conductor shall conform to IEC 62783-1 and to the detail
specifications.
5.4.4 Tensile strength of the insulation
The tensile strength of the insulation shall conform to IEC 62783-1 and to the detail
specifications.
5.4.5 Elongation at break of the sheath
The elongation at break of the sheath shall conform to IEC 62783-1 and to the detail
specifications.
5.4.6 Tensile strength of the sheath
The tensile strength of the sheath shall conform to IEC 62783-1 and to the detail
specifications.
5.4.7 Crush test of the cable
The crush resistance of the cable shall conform to IEC 62783-1 and to the detail
specifications.
5.4.8 Impact test of the cable
The impact resistance of the cable shall conform to IEC 62783-1 and to the detail
specifications.
– 12 – IEC 62783-2:2019 © IEC 2019
5.4.9 Repeated bending of the cable
The resistance to repeated bending shall conform to IEC 62783-1 and to the detail
specifications.
5.4.10 Tensile performance of the cable
The tensile performance shall conform to IEC 62783-1 and to the detail specifications.
5.5 Environmental tests
5.5.1 Shrinkage of the insulation
The shrinkage of the insulation shall conform to IEC 62783-1 and to the detail specifications.
5.5.2 Wrapping test of the insulation after thermal ageing
The ageing performance of the insulation shall conform to IEC 62783-1 and to the detail
specifications.
5.5.3 Bending test of the insulation at low temperature
The cold bend test performance shall conform to IEC 62783-1 and to the detail specifications.
5.5.4 Tensile strength and elongation of the sheath after ageing
The tensile strength and elongation at break of the sheath after agei
...