IEC 61935-2:2003

INTERNATIONAL IEC
STANDARD
61935-2
First edition
2003-05
Generic cabling systems –
Specification for the testing of balanced
communication cabling in accordance
with ISO/IEC 11801 –
Part 2:
Patch cords and work area cords

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INTERNATIONAL IEC
STANDARD
61935-2
First edition
2003-05
Generic cabling systems –
Specification for the testing of balanced
communication cabling in accordance
with ISO/IEC 11801 –
Part 2:
Patch cords and work area cords

 IEC 2003  Copyright - all rights reserved
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mechanical, including photocopying and microfilm, without permission in writing from the publisher.
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International Electrotechnical Commission
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For price, see current catalogue

– 2 – 61935-2  IEC:2003(E)
CONTENTS
FOREWORD . 4

INTRODUCTION .5

1 Scope . 6

2 Normative references. 6

3 Definitions . 6

4 General requirements and test configuration. 6

4.1 Cable and connector design . 6

4.2 Cable and connector tests . 7
4.3 Test configuration and equipment . 7
4.4 Modular plug cord tests requirements. . 8
4.5 Pass/fail test limits. 8
5 Acceptance tests . 8
5.1 Visual inspection . 8
5.2 Wire map. 9
5.3 Propagation delay.10
5.4 Delay skew .10
5.5 Insertion loss/operational attenuation .10
5.6 Return loss .10
5.7 Near End Crosstalk Attenuation (NEXT) .13
6 Periodic tests.15
6.1 General .15
6.2 Tensile strength.15
6.3 Flexure .16
6.4 Bending/twisting .17
6.5 Crushing.18
6.6 Dust test.19
6.7 Coupling attenuation.21
6.8 Climatic sequence .21
7 Test head requirements .22
7.1 General .22
7.2 Compliance with category 6 requirements.22
7.3 Additional FEXT requirements .22

7.4 Additional return loss requirements.22
7.5 NEXT loss centring requirements.22
7.6 Adjustment of connector NEXT assumptions.23
Figure 1 – Transmission performance test configuration for patch cords. 7
Figure 2 – Correct pairing .9
Figure 3 – Incorrect pairing .9
Figure 4 – Test arrangement for the return loss.10
Figure 5 – TDR response .11
Figure 6 – Calibration procedure .12
Figure 7 – Network analyzer configuration.15
Figure 8 – Fixture for cable assembly flexure test .16
Figure 9 – Bending test: assembly in U shape.17

61935-2  IEC:2003(E) – 3 –
Figure 10 – Twisting test: assembly in U shape.18

Figure 11 – Fixture for cable crushing test .19

Figure 12 – Measuring device .21

Figure 13 – Centring of NEXT properties of the test head.23

Table 1 – Uncertainty band of return loss measurement .12

– 4 – 61935-2  IEC:2003(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
GENERIC CABLING SYSTEMS –
SPECIFICATION FOR THE TESTING OF BALANCED COMMUNICATION

CABLING IN ACCORDANCE WITH ISO/IEC 11801 –

Part 2: Patch cords and work area cords

FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the 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, the IEC publishes International Standards. 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. The 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 the 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 National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports or guides and they are accepted by the National
Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61935-2 has been prepared by subcommittee SC 46A:Coaxial
cables, of IEC technical committee TC 46: Cables, wires, waveguides, r.f. connectors, r.f. and
microwave passive components and accessories.
The text of this standard is based on the following documents:
FDIS Report on voting
46A/532/FDIS 46A/544/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until
2004. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
A bilingual edition of this standard may be issued at a later date.

61935-2  IEC:2003(E) – 5 –
INTRODUCTION
Modular plug cords are constructed for connecting equipment using modular connecting

hardware. It is known that connecting hardware performance is subject to influence by the

properties of the modular plug termination and therefore modular plug cords should be tested

to determine the quality of the assembly. Moreover, the performance of modular plug cords

may differ due to the performances of the involved separate components depending upon

the efficiency of the manufacturing procedure. Manufacturing procedures also impact on the

reliability of these cords. Therefore, the object of this standard is to provide test methods to

ensure compatibility of modular plug cords to be used in cabling according to ISO/IEC 11801.

Also, it provides test methods and associated requirements to demonstrate the performance

and reliability of these cords during their operational lifetime.

– 6 – 61935-2  IEC:2003(E)
GENERIC CABLING SYSTEMS –
SPECIFICATION FOR THE TESTING OF BALANCED COMMUNICATION

CABLING IN ACCORDANCE WITH ISO/IEC 11801 –

Part 2: Patch cords and work area cords

1 Scope
This part of IEC 61935 provides methods to ensure compatibility of modular plug cords to be
used in cabling according to ISO/IEC 11801 and also provides test methods and associated
requirements to demonstrate the performance and reliability of these cords during their
operational lifetime.
2 Normative references
The following referenced documents are indispensable for the application 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 60068-2-61:1991, Environmental testing – Part 2-61: Test methods – Test Z/ABDM:
Climatic sequence
IEC 60603-7, Connectors for frequencies below 3 MHz for use with printed boards
IEC 60603-7-4, Connectors for electronic equipment – Part 7-4: Detail specification for 8-way,
unshielded, free and fixed connectors, for data transmissions with frequencies up to 250 MHz
(CAT 6, unshielded)
IEC 61156, Multicore and symmetrical pair/quad cables for digital communications
IEC 61935-1:2000, Generic cabling systems – Specification for the testing of balanced
communication cabling in accordance with ISO/IEC 11801 – Part 1: Installed cabling
ISO/IEC 11801:2002, Information technology – Generic cabling for customer premises
3 Definitions
For the purposes of this document, the definitions in IEC 61935-1 apply
4 General requirements and test configuration
4.1 Cable and connector design
The design of the cables and connectors should conform to the applicable parts of IEC 61156
and IEC 60603 respectively as referred to into the ISO/IEC 11801.

To be published.
61935-2  IEC:2003(E) – 7 –
4.2 Cable and connector tests
Cables and connectors used in cable assemblies should be tested separately in accordance with

IEC 61156-1 and 60603-7 respectively, even if they are not described in the IEC 61156-1 or the

IEC 60603-7 series. These component tests do not need to be repeated on the cable assembly.

4.3 Test configuration and equipment

The reference measurement procedures that are described in this standard require the use of

a network analyzer, r.f. transformers (baluns), twisted pair (TP) test leads and impedance

matching terminations. Refer to IEC 61935-1 for requirements of test equipment. The nominal

impedance for the test set-up and the terminations is 100 Ω. The same tests may be used
for 120 Ω and 150 Ω patch cords, but the measurement methods have not been evaluated for
these nominal impedance values.
The test configuration includes terminating test heads at each end of the patch cord as shown
in Figure 1. The terminals on the test heads interface with the test equipment. Refer to IEC
61935-1 for detailed connection diagrams. All wire pairs shall be terminated with differential
and common mode terminations per IEC 61935-1. Resistive type terminations are preferred.
50 Ω
D
G
C
2a
2b
C
G
D
50 Ω
IEC  1248/03
Key
1 Test interface 5 Modular cord under test
2a Network analyzer - IN 6 Ground plane
2b Network analyzer - OUT 7 Far end test head
3 Near end test head
4 Balun
Figure 1 – Transmission performance test configuration for patch cords
50 Ω
50 Ω
25 Ω 25 Ω
50 Ω
50 Ω
50 Ω
50 Ω
25 Ω 50 Ω 50 Ω
25 Ω
50 Ω
50 Ω
50 Ω
50 Ω
– 8 – 61935-2  IEC:2003(E)
4.4 Modular plug cord tests requirements

The test methods described in this specification characterize modular plug cords. For

certification purposes the test schedule refers to these tests.

The patch cord test requirements include tests that can be performed on each patch cord or

representative samples produced and tests that are only performed on representative

samples of patch cords. The sampling only tests (known as periodic tests) include:

• tensile strength;
• flexure;
• bending/twisting;
• crushing;
• dust test;
• climatic sequence;
• coupling attenuation.
The periodic tests are described in detail in Clause 6.
The tests that can be performed on each patch cord include (acceptance tests):
• visual inspection;
• wire map;
• pair-to-pair NEXT;
• return loss.
If the components used to assemble the patch cord are not certified to be compliant, the
following additional tests should be performed:
• insertion loss (attenuation);
• ELFEXT;
• propagation delay;
• delay skew;
• d.c. resistance;
• d.c. resistance unbalance.
The requirements to be verified on each patch cord are described in detail in Clause 5.

4.5 Pass/fail test limits
Pass/fail for the test procedure in this document may be affected by the measured properties
of the test heads, as defined in Clause 7
5 Acceptance tests
5.1 Visual inspection
Visual inspection of cords and work area cords is performed by observing with normal or
corrected vision without any additional magnification:
• the condition, workmanship and finish are satisfactory;
• the marking, when specified in the relevant specification, is legible;
• mechanical damage is absent and there is no undesired movement or displacement of parts;

61935-2  IEC:2003(E) – 9 –
• flaking of materials or finishes is absent;

• the length as specified.
5.2 Wire map
A conductor map test is intended to verify correct pin termination at each end and to check for
installation connectivity errors. For each of the conductors in the cable, and the screen(s), if

any, the conductor map indicates:

• continuity to the remote end;

• shorts between any two or more conductors/screen(s);

• transposed pairs;
• reversed pairs;
• split pairs;
• any other connection errors.
1 1
2 2
3 3
6 6
5 5
4 4
7 7
8 8
S S
IEC  1249/03
Figure 2 – Correct pairing
A reversed pair occurs when the polarity of one wire pair is reversed at one end of the link.
See Figure 3a for an illustration of a reversed pair.
NOTE 1 In English, also called a tip/ring reversal.
A transposed pair occurs when the two conductors in a wire pair are connected to the position
for a different pair at the remote connection. See Figure 3b for an illustration of transposed
pairs.
NOTE 2 Transposed pairs are sometimes referred to as crossed pairs.
Split pairs occur when pin to pin continuity is maintained but physical pairs are separated.
See Figure 3c for an illustration of split pairs.

1 1 1 1 1 1
2 2 2 2 2 2
3 3 3 3 3 3
6 6 6 6 6 6
5 5 5 5 5 5
4 4 4 4 4 4
7 7 7 7 7 7
8 8 8 8 8 8
S S S S S S
1 2 3
IEC  1250/03 IEC  1251/03 IEC  1252/03
Figure 3a – Figure 3b – Figure 3c – Split
Reversed pair Transposed pairs pairs
Figure 3 – Incorrect pairing
Wire map tests shall report "Pass" if cabling is determined to be correct.

– 10 – 61935-2  IEC:2003(E)
5.3 Propagation delay
Propagation delay is assumed to be met by design when using cables and connectors that

comply with IEC 61156 and IEC 60603-7 respectively. Propagation delay shall be measured in

accordance with clause 4.5 of IEC 61935-1.

5.4 Delay skew
Delay skew is assumed to be met by design when using cables and connectors that comply

with IEC 61156 and IEC 60603-7 respectively. Delay skew shall be measured in accordance

with clause 4.5 of IEC 61935-1.

5.5 Insertion loss/operational attenuation
Insertion loss is assumed to be met by design when using cables and connectors that comply
with IEC 61156 and IEC 60603-7 respectively. Insertion loss shall be measured in accordance
with clause 4.4 of IEC 61935-1.
5.6 Return loss
5.6.1 Object
The object of this test is to measure the return loss of cord (i.e. a flexible cable with two
attached connectors) at the reference planes from both ends.
5.6.2 Test method
Return loss is derived from the measured value of the scattering parameter, S11, of the cord.
5.6.3 Test set-up
The test set-up consists of a network analyzer four baluns as defined in IEC 61935-1, 4.2.6,
two reference jacks and a reference plug .The definition of reference jack and reference plug
is intended to ensure the inter-operability of any cord when inserted in any channel. In this
document, two options are described. It is assumed that they give identical results. It is not
necessary to terminate the pairs not under test. The pair under test shall be terminated with a
precision resistor through a reference jack.
IEC  1253/03
Key
1 4-baluns, common and 4 Reference jack
differential mode terminated
5 Patch cord under test
(any length)
2 Differential mode, 100 ohm ±1%
resistor terminations
3 Network analyzer
Figure 4 – Test arrangement for the return loss

61935-2  IEC:2003(E) – 11 –
5.6.3.1 Reference plug
5.6.3.1.1 Option a
The reference plug that is used for calibration is built either using a short terminated cable
lead (i.e. shorter than 3,5 cm) having an impedance of 100 Ω ± 1,5 Ω or a PCB designed in
such a way that it provides 100 Ω well-matched lines.(equal or better than 100 Ω ± 1,5 Ω).

The reference plug shall not contain any compensation and shall be designed to minimize the

length of any mismatch.
5.6.3.1.2 Option b
When the test head meets the requirements of Clause 7, there is no need for any reference
plug.
5.6.3.2 Reference jack
5.6.3.2.1 Option a
To mate the cord to the balun, a reference jack shall be used. The RL (in frequency domain)
of the reference jack, when mated to the loaded refere
...