IEC 62783-2:2025

IEC 62783-2 ®
Edition 2.0 2025-10
INTERNATIONAL
STANDARD
REDLINE VERSION
Twinax cables for digital communications -
Part 2: Family specification - Cable for Ethernet-over-twinax physical interfaces
ICS 33.120.20 ISBN 978-2-8327-0782-1

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CONTENTS
FOREWORD . 3
INTRODUCTION . 1
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Requirements for cables construction . 7
4.1 General remarks . 7
4.2 Cable construction . 7
4.2.1 General . 7
4.2.2 Conductor . 7
4.2.3 Insulation . 7
4.2.4 Colour code . 7
4.2.5 Drain wire . 7
4.2.6 Screening of cable assembly element . 7
4.2.7 Cable make-up . 7
4.2.8 Screening of the cable core . 7
4.2.9 Sheath . 8
4.2.10 Colour of sheath . 8
4.2.11 Identification . 8
4.2.12 Finished cable . 8
5 Requirements and test methods . 8
5.1 General remarks . 8
5.2 Electrical tests . 9
5.2.1 Conductor resistance . 9
5.2.2 Resistance unbalance. 9
5.2.3 Dielectric strength . 9
5.2.4 Insulation resistance . 9
5.2.5 Mutual capacitance .
5.2.5 Surface transfer impedance . 9
5.2.6 Coupling attenuation . 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 pair skew, and intra-element delay
pair skew . 10
5.3.6 Near-end crosstalk (NEXT) . 10
5.3.7 Attenuation to crosstalk ratio far-end (ACR-F)
5.3.7 Far-end crosstalk (FEXT) . 10
5.3.8 Transverse conversion loss (TCL) .
5.3.8 Differential-mode to common-mode conversion (S ) . 10
cd21
5.3.9 Equal level transverse conversion transfer loss (ELTCTL)
(S – S ) . 10
cd21 dd21
5.3.10 Screening attenuation .
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 Cold impact test of the cable . 11
5.4.9 Repeated bending of the cable . 11
5.4.10 Tensile performance of the cable . 11
5.4.11 Vibration test of the cable . 11
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 Damp heat steady state . 12
5.5.9 Salt mist . 12
5.5.10 Flame propagation characteristics of a single cable . 12
5.5.11 Flame propagation characteristics of bunched cables . 12
5.5.12 Smoke generation . 12
5.5.13 Halogen-free compounds test . 13
Annex A (informative) Supported ISO/IEC/IEEE 8802-3 Ethernet-over-twinax PHYs . 14
A.1 General . 14
A.2 Ethernet-over-twinax PHY transmission specifications . 14
Bibliography . 15

Table 1 – Supported IEEE 802.3 Ethernet-over-twinax implementations, configurations
Table 2 – Supported IEEE 802.3 Ethernet-over-twinax implementations,
transmission requirements .
Table 1 – Supported ISO/IEC/IEEE 8802-3 Ethernet over twinax PHY link segment
specifications . 8
Table A.1 – Supported ISO/IEC/IEEE 8802-3 Ethernet-over-twinax PHY transmission
specifications . 14

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Twinax cables for digital communications -
Part 2: Family specification -
Cable for Ethernet-over-twinax physical interfaces

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