End to End Links
A new Ethernet channel definition to help Customers

Bob Lounsbury
Principal Engineer, Rockwell Automation
Rockwell Automation
Presented at the ODVA2017 Industry Conference & 18th Annual Meeting
February 21-23, 2017
Palm Harbor, FL, USA
Abstract
As Ethernet expands so does the methods of measuring the cabling system performance. Industrial
customers tend to install cables and then terminate in-place. The quality of the field termination isdependent on many factors including wire end preparation. The cables and connectors used in thechannel may meet or exceed the component specifications, but if improperly terminated the link orchannel may not. The cabling industry channel definitions and tests do not include the plugs (orconnections) at the two ends of the channel. This means that, if the ends of the cables are improperly
prepared the channel will pass but the performance may be less than satisfactory. The international
standards committees for industrial have been working to define a new definition called End to End Links(E2E Links). These links not only include the connections between the two ends but also include the end
connections. This paper will discuss these new links and how they will help your customers and field
service personnel diagnose cable problems and verify cabling in the field.

Keywords
Physical Layers, Ethernet, IEC, ISO/IEC, TIA, E2E Links, MICE, Automation Island,2015 ODVA Industry Conference

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White Paper
Preface
The use of long cords is common practice in the design and deployment of industrial control networks.
Long cords (greater than 10M) are outside the current “Generic Cabling” specifications. Further thesecords are typically assembled and terminated in situ. Since this practice has been used for years, there isvoid in performance Verification and Certification testing. Currently, an owner/operator has no way todetermine if the Link meets the necessary performance level to assure the cabling will support theintended applications. The E2E Link attempts to address the testing issues with Industrial Links and has
been defined for the most common Link configurations.

Back Ground
Within the structured cabling systems exists 4 cabling subsystems, Campus, Building, Floor andIntermediate see Figure 1.
CD

BD

FD

ID/IIDTO/AO

NICampusbackbonecablingsubsystem

Building
backbonecablingsubsystem

Floorcablingsubsystem

Apparatus
network

Intermediate
cablingsubsystem

Apparatus
attachment
cabling

Generic Cabling System ISO/IEC11801-2

Automation
Island Cabling

Industrial Cabling System

Figure 1 System and Subsystems

The subsystems are distributers (CD, BD, and FD and ID/IID) where cross connects are housed. The
distributors can be located in Entrance Facilities, Equipment rooms, Telecommunications
rooms/enclosures. The area of focus for this paper is the cabling extending from the Telecommunications
room/enclosure where the ID/IID may be installed. This cabling consists of the last cross connect orInterconnect, horizontal cabling and the work-area components. Leading into the Apparatus network andwithin the Apparatus Network exists many cabling connections (Channels) between equipment interfaces
see Figure 2.
IID/ID

Patch Cord/
JumperC
EQP C
Equipment
Cord

C

Apparatus Attachment
Cord
TO/AO
C
C NI

ID

Equipment
Cord
C
EQP C

Apparatus Attachment
Cord
C

C

NI

Patch Cord/
JumperChannel

P-Link/Horizontal

Figure 2 Example of Channel and P-Link

The horizontal cabling systems are also called Permanent links (P-Link) see Figure 2. These Permanent
links include the horizontal cable between the patch panel and the work area outlet. The Permanent link
and the work area cabling (work area cords) make up a Channel. Work area cords are sometimes
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mistermed as patch cords. Most industrial point to point links fall within the work area cord definitions.
The standards limit the channel length to 100 Meters maximum. The length elements of the channel areparsed out as follows, Cords 10 Meters, Horizontal cabling 90 Meters, totaling 100 Meters. Each of theelements that make up the channel have individual test specifications that have been defined by the
cabling standards bodies.

Long Cords
For Industrial installations long cords are commonly used for point to point connections without patch
panels or cross connects. In this case the point to point connections are said to make up the channel froma test perspective. For example a Permanent link begins and ends with Jacks see Figure 3. A cord
begins and ends in plugs, but are mostly limited to 10 meters max. The above figures show a typical
Generic configuration of a connection between equipment and NI interfaces. These connections are
greatly simplified using the long cords as shown in Figure 4.

Equipment Cord

EQP

TI

P-LinkFixed Cabling
90M max.

TI

Work Area Cord

NI

TI

TI

Channel 100M max.

Figure 3 Test Demarcation points of a P-Link and Channel

EQP C

C

NI

Figure 4 Direct Link (Cord)

Testing
Testing of these sub elements of a channel are all inclusive with respect to the components that makethem up. Remember that a channel is made up of all cords (equipment cords cross connect cords andwork area cords) and the Permanent link. This is not true for a channel test. While physically both ends
of a channel have plugs the channel test excludes the plugs at both ends, see Figure 3 above. The
channel test, theoretically will not find transmission performance problems if they are presented at theend plugs. To solve this problem, E2E Links was created. The E2E Links define the Link to include thetwo end plugs. The process of redefining the channels to include the end plugs. The channel models had
to be modified to include transmission models of the last two connections as shown in Figure 6 throughFigure 13 below.

Bulkheads
It is common in Industrial installations to use Bulkhead connectors to enter and exit enclosures. The useof Bulkhead connectors present some modeling challenges in that their transmission performance is nottightly regulated by the cabling standards. The modeling has to take this into consideration.
Schematically the bulkhead looks like that detailed in Figure 5 below. The three variants span from one
physical connection with a cable to two physical connectors equaling 1 or two connections. As you cansee, the three variants can electrically pose technical problems in the modeling of connections.

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Bulkhead Connections

Bulkhead mounted connection <= 10 cm then treated as one
with fixed cableconnection> 10 cm is treated as 2
connections

Figure 5 Examples of Bulkhead Connections

The generic standards define a channel to have a maximum of 4 connections. They do not count the end
device connections since the plugs are not part of the channel definition. While the industrial standards
do allow bulkheads that equal 2 connections, the channel definitions do not support exceeding the 4connections allowed in the channel.
Since E2E links now include the two connections at the end of the link, we now speak of 6 connections (4channel and 2 link ends). The reader will see this in the following E2E Link examples later in this paper.

Limit Lines
This paper will show the differences between the limit lines of a Channel and E2E Links. Further thispaper will describe the field testing process for the E2E Links. There are 3 sets of primary measurements(Insertion Loss, Return Loss and NEXT) to describe the transmission performance of an E2E Link. In
addition there are another 3 that are derivatives of the primary limits in the form of Power Sum
measurements (PSACRF (Attenuation Cross Talk Ratio), PSACRF and PSNEXT. ACRF is similar to the
FEXT (Far End Cross Talk) measurement.

Applications and Performance Levels
Applications supported by cabling are categorized by their bandwidth requirements requiring different
performance levels. In the US the standards define cabling performance levels using “Category”
designations (i.e.; Category 5, Category 5e, Category 6 …..). In the international community the cabling
performance levels are defined as Classes, (i.e.; Class D, Class E, Class EA….). Since the E2E Link is
the responsibility of ISO/IEC, Classes are used to describe the performance levels for Channels,
Permanent Links (P-Links) and E2E Links. As in the Channel and P-Link, the E2E Link limits aredescribed by a set of equations as a function of frequency. The upper end of the frequency range isdefined by the bandwidth requirements of the supported applications. The equations along with theirgraphs are provided in this paper for comparison purposes.

ODVA BW Requirements
While ODVA only supports up to 100Mb/s Ethernet, Category 5E/Class D channels supports to 1Gb/s.
However the E2E Link definitions are extended to Category 6/Class E Links. There are good reasons to
use Category 6/Class E links, as these class of cables have extended performance specifications to help
reduce the effects of noise on the system. There are even better reasons to use cabling defined by
ODVA and the industrial standards in ANSI/TIA as these are designed to support the applications while inhigh noise, common in Industrial environments. The modeling and limit line definitions for E2E links weremodeled to support both Class D and Class E Links.

E2E Link Performance Limits
The critical cabling parameters are as listed below in Table 1.
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Table 1 Critical Cabling Parameters

Parameter (Standard)
Insertion Loss
Return Loss
Impedance
Near end Cross Talk
Far End Cross Talk
Power Sum NEXT
Power Sum Far End Cross Talk
Delay
Delay Skew

Comments

IL
RL
Z
NEXT
FEXT (ACRF)
PS NEXTPSACRF
Delay
Delay Skew

Parameter (Extended)
Transverse Conversion Loss
Equal Level Transverse
Conversion Transfer Loss
Coupling Attenuation
DC Resistance
DC Resistance unbalance

Measured
Measured
Measured
Measured
Measured
Derived
DerivedMeasured
DerivedComments

TCL
ELTCTL

Measured
MeasuredCA
DCR
DCR unbalance

Measured Lab only
Measured important for POE
Measured important for POE

Today’s field testers have the ability to do all of the above tests with the exception of Coupling
Attenuation.

E2E Link Examples
The following schematic diagrams detail the supported E2E Links. These links are supported bymodeling cases and by new limits for testing. It should be noted that, while the generic standards only
allow for 4 connections in a channel, E2E Links add the last two end connections, totaling 6 connections
maximum. Physically there is no change in the allowed connections in a channel, but from a modelingand electrical definition perspective there is now 6 connections. The following schematic figures areprogressively arranged in complexity. In addition the Test Interface (TI) markers now show that theconnections are part of the definition, thus part of the measurements. In the schematics a connection issymbolized as:

L1 ≤ 100M
Test EQP

Test EQP
C1

TI

TI

Figure 6, One Segment, 2 Connection E2E Link

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L1 ≤ 100M
Test EQP

Test EQP
C1

C2

TI

TI

Figure 7, Two Segment, Three Connection E2E Link

L1
Test EQP

Test EQP
C1

C2

C3

TI

TI

Figure 8, Three Segment, Four Connection E2E Link

L1 ≤ 100M
1 connection

1 connection

Test EQP

Test EQP
C1

C2

C3

TI

TI

Figure 9, Three Segment, Four Connection E2E Link

L1 ≤ 100M
Test EQP

Test EQP
C1

1 connections

C2

1 connections

C3

TI

TI

Figure 10, Three Segment, Four Connection E2E Link

L1 ≤ 100M
Test EQP

Test EQP
C1

2 connections

2 connections

C2

C3

TI

TI

Figure 11, Three Segment, Six Connections E2E Link

L1 ≤ 100M
Test EQP

Test EQP
C1

C2

C3

C4
TI

TI

Figure 12, Four Segment, Five Connection E2E Link

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L1 ≤ 100M

Test EQP

Test EQP
C1

C2

C3

C4

C5
TI

TI

Figure 13, Five Segment, Six Connection, E2E Link

It should be noted that Figure 11 is equivalent to a full Generic cross connect channel. In addition while
the schematics show cords as segments, the segments can be P-Links

E2E Link Equations and Test Limits
The addition of the two end plugs has an impact on the channel modelling that causes the limit lines tochange accordingly. For each E2E link case there is a corresponding modeling case. In addition thesecases are repeated for Class D and Class E E2E Links. Where possible the Channel graph limits areprovided for comparison.

Insertion Loss
Equation 1 Class D E2E Link Insertion LossClass D E2E link insertion loss dB [n = number of connections 2-6]
𝐿
0.2(
) ∙ (1,9108 ∙ √𝑓 + 0,0222 ∙ 𝑓 +) + (𝑛 ∙ 0,04 ∙ √𝑓)
100√𝑓
NOTE 1 To align with ISO/IEC 11801-1 permanent link requirements, themaximum length for 1- and 2-segment E2E links is 90 m
NOTE 2

Calculated values less than 4 dB revert to 4 dB

For connections numbers > 2 (L/100) is replaced with 1.05

Figure 14 E2E Link Worst Case Class D Insertion Loss2015 ODVA Industry Conference

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Figure 15 ISO Worst Case Class D Channel Insertion Loss

Equation 2 Class E E2E Link Insertion LossClass E E2E link insertion loss [n = number of connections 2-6]
dB
𝐿
0.25
(
) ∙ (1,82 ∙ √𝑓 + 0,0169 ∙ 𝑓 +) + (2 ∙ 0,02 ∙ √𝑓)
100√𝑓
NOTE 1 To align with ISO/IEC 11801-1 permanent link requirements, the maximum
length for 1- and 2-segment E2E links is 90 m.
NOTE 2

Calculated values less than 4 dB revert to 4 dB.

For connections numbers > 2 (L/100) is replaced with 1.05

Figure 16 E2E Link Worst Case Class E Insertion Loss2015 ODVA Industry Conference

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Figure 17 ISO Worst Case Class E Channel Insertion Loss

Return Loss
Equation 3 Class D Worst E2E Link Return LossClass D E2E link return loss 6 ConnectionsdB
1 ≤ 𝑓 ≤ 20
20 < 𝑓 ≤ 1002015 ODVA Industry Conference

17 − (0,27 + (1,29 ∙ (

𝑓−1
99

)))

30 − 10 ∙ log⁡(𝑓) − (0,27 + (1,29 ∙ (

9

𝑓−1
99

)))

©2015 ODVA, Inc.

Figure 18 E2E Link Worst Case Class D Return Loss

Figure 19 ISO Worst Case Class D Channel Return Loss

Equation 4 Class E Worst E2E Link Return LossClass E E2E link return loss 6 ConnectionsdB
1 ≤ 𝑓 ≤ 10

19 − (0,55 + (1,47 ∙ (

𝑓−1
249

)))
𝑓−1

10 < 𝑓 ≤ 40

24 − 5 ∙ log⁡(𝑓) − (0,55 + (1,47 ∙ (40 < 𝑓 ≤ 250

32 − 10 ∙ log⁡(𝑓) − (0,55 + (1,47 ∙ (2015 ODVA Industry Conference

10

249

)))

𝑓−1
249

)))

©2015 ODVA, Inc.

Figure 20 E2E Link Worst Case Class E Return Loss

Figure 21 ISO Worst Case Class E Channel Return Loss

NEXT Limits
Equation 5 Class D Worst E2E Link Return LossClass D E2E link NEXT 6 ConnectionsdB
65,3−15∙log⁡(𝑓)
83−20∙log⁡(𝑓)
𝑓−1−20+ 2 ∙ 10 −20)) − (1,26 ∙ ())(−20 ∙ 𝑙𝑜𝑔 (10
NOTE

99

Calculated values greater than 65 dB revert to 65 dB.

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Figure 22 E2E Link Worst Case Class D NEXT Loss

Figure 23 ISO Worst Case Class D Channel NEXT2015 ODVA Industry Conference

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Equation 6 Class E Worst E2E Link NEXT LossClass E E2E link NEXT 6 ConnectionsdB
74,3−15∙log⁡(𝑓)
94−20∙log⁡(𝑓)
𝑓−1−20+ 2 ∙ 10 −20)) − (2,38 ∙ ())(−20 ∙ 𝑙𝑜𝑔 (10
NOTE

249

Calculated values greater than 65 dB revert to 65 dB.

Figure 24 E2E Link Worst Case Class E NEXT Loss

Figure 25 ISO Worst Case Class E Channel NEXTPSNEXT2015 ODVA Industry Conference

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Equation 7 Class D Worst E2E Link PSNEXT LossClass D E2E link PSNEXT 6 ConnectionsdB
62,3−15∙log⁡(𝑓)80−20∙log⁡(𝑓)
𝑓−1−20+ 2 ∙ 10 −20)) − (1,26 ∙ ())(−20 ∙ 𝑙𝑜𝑔 (1099

In cases where measured insertion loss is less than 4 dB, the pass/fail limits for
PSNEXT should not apply.

Figure 26 E2E Link Worst Case Class D PSNEXT Loss

Figure 27 ISO Worst Case Class D Channel PSNEXT Loss2015 ODVA Industry Conference

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Equation 8 Class E Worst E2E Link PSNEXT LossClass E E2E link PSNEXT 6 ConnectionsdB
72,3−15∙log⁡(𝑓)90−20∙log⁡(𝑓)
𝑓−1−20+ 2 ∙ 10 −20)) − (2,38 ∙ ())(−20 ∙ 𝑙𝑜𝑔 (10249Figure 28 E2E Link Worst Case Class E PSNEXT Loss

Figure 29 ISO Worst Case Class E Channel PSNEXT Loss

ACR-F Limits

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Equation 9 Class D Worst E2E Link ACR-F
Class D E2E Link ACR-F 6 ConnectionsdB
63,8−20∙log⁡(𝑓)75,1−20∙log⁡(𝑓)−20−20+ 4 ∙ 10)) − 1,12(−20 ∙ 𝑙𝑜𝑔 (10ACR-F at frequencies that correspond to measured FEXT values of greater than
70,0 dB are for information only.

Figure 30 E2E Link Worst Case Class D ACR-F

Figure 31 ISO Worst Case Class D Channel ACR-F

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Equation 10 Class E Worst E2E Link ACR-F
Class E E2E Link ACR-F 6 ConnectionsdB
67,8−20∙log⁡(𝑓)83,1−20∙log⁡(𝑓)−20−20+ 4 ∙ 10)) − 0,46(−20 ∙ 𝑙𝑜𝑔 (10ACR-F at frequencies that correspond to measured FEXT values of greater than
70,0 dB are for information only.

Figure 32 E2E Link Worst Case Class E ACR-F

Figure 33 ISO Worst Case Class E Channel ACR-F

PSACR-F2015 ODVA Industry Conference

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Equation 11 Class D Worst E2E Link PSACR-F
Class D E2E link PSACR-F
dB
60,8−20∙log(𝑓)72,1−20∙log(𝑓)−20−20+ 4 ∙ 10)) − 1,12(−20 ∙ 𝑙𝑜𝑔 (10Figure 34 E2E Link Worst Case Class D PSACR-F

Equation 12 Class E Worst E2E Link PSACR-F
Class E E2E link PSACR-F
dB
64,8−20∙log⁡(𝑓)80,1−20∙log⁡(𝑓)−20−20+ 4 ∙ 10)) − 0,46(−20 ∙ 𝑙𝑜𝑔 (10NOTE

Calculated values greater than 62 dB revert to 62 dB2015 ODVA Industry Conference

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Figure 35 E2E Link Worst Case Class E PSACR-F

TCL (UN-Screened Cables)
Equation 13 Class D&E Worst E2E Link TCL for MICE Levels E1, E2 and E3ClassClass D&EaFrequency
MHz

E2E link TCL
dB a
E1

E2

E3

1  f  30

53-15log(f)63-15log(f)73-15log(f)30  f  100

60,4-20log(f)70,4-20log(f)80,4-20log(f)TCL at frequencies that correspond to calculated values of greater than 40 dB
revert to 40 dB.

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Figure 36 E2E Link Worst Case Class D TCL

Figure 37 ISO TCL Class D Channel

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Figure 38 E2E Link Worst Case Class E TCLELTCTL (UN-Screened Cables)
Equation 14 Class D&E Worst E2E Link ELTCTL for MICE Levels E1, E2 and E3ClassClass D&EaFrequencyMHz1  f  30

E2E link ELTCTL
dB a
E1

E2

E3

30-20log(f)40-20log(f)50-20log(f)ELTCTL at frequencies that correspond to calculated values of greater than
40 dB revert to 40 dB.

Figure 39 E2E Link Worst Case Class D & E ELTCTL
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Figure 40 ISO Worst Case Class D & E ELTCTL

Coupling Attenuation (Screened Cables)
Equation 15 Class D&E Worst E2E Link CA for MICE Levels E1, E2 and E3Class

FrequencyMHz1  f  30

Class D&E

1  f  1002015 ODVA Industry Conference

E2E link CA MICE E1, E2 and E3
dB
E1

E2

E3

40

50

60

80-20log(f)90-20log(f)90-20log(f)22©2015 ODVA, Inc.

Figure 41 E2E Link Worst Case Class D & E CA

Testing of E2E Links
Field tester manufactures were quick to respond to the work in ISO/IEC in enhancing the field testers toinclude new limits for E2E Links. In some cases this requires a new test head since the tester is notproviding part of the connection at the end of a link. This is very similar to P-Link testing where the tester
provides a reference plug to interface with the P-Link jacks. The new releases of field testers now include
the E2E Link limit lines and also TCL and ELTCTL measurement capabilities. This is a huge benefit toour customers who need to install, maintain and troubleshoot networks. Problems that exist but were notvisible can now be found by the field testers supporting these capabilities.

Conclusion
The installation of E2E links is not new in industrial installations, what is new is the ability to test the links.
The addition of this new set of cabling specifications effectively adds a new element to the cabling
standards. We now have testable definitions for the Channel, E2E Link, P-Link and Cords that collectively
make up a network. From a modeling perspective the greatest addition is the connection models being
added to the Channel. The impact as seen in the comparative graphs above is in insertion loss andreturn loss. The addition of the two end connections adds additional losses. In general the greatest
impact to RL is reflections occurring at the connection interfaces (including wire terminations within theplug and jack beck ends). It makes sense that the RL would be effected since the first interface alaunched signal sees now is the connections at the end of the link. So we see a degradation in RL for an
E2E Lind definition. It should be noted that this degradation is not new since all channels have the sameproblem except it is now visible in an E2E link measurement. NEXT is also effected by the modelingsince there is a potential to see incorrect routing of the cord conductors within the back end of the plug ofan end connection. This is the single greatest benefit of the E2E link definitions. The wire preparation
during plug termination of field installed links is the single most important issue solved by the E2E link
definitions. Unfortunately the balance specifications were not enhanced during this project. Since thecabling’s TCL, ELTCTL are the most important parameters for high noise environments.

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References:SC25-11801-9902-Ed1-CDTR -- Information Technology – Generic Cabling for Customer Premises, Part
9902: Specifications for End-to-End Link Configurations
ISO/IEC 11801 Information Technology Generic Cabling for Customer Premises
ISO/IEC 29106 Information Technology Generic Cabling – Introduction to the MICE Environmental
Classification******************************************************************************************************************************************************The ideas, opinions, and recommendations expressed herein are intended to describe concepts of the author(s) for the possible useof ODVA technologies and do not reflect the ideas, opinions, and recommendation of ODVA per se. Because ODVA technologies
may be applied in many diverse situations and in conjunction with products and systems from multiple vendors, the reader andthose responsible for specifying ODVA networks must determine for themselves the suitability and the suitability of ideas, opinions,and recommendations expressed herein for intended use. Copyright ©2017 ODVA, Inc. All rights reserved. For permission to
reproduce excerpts of this material, with appropriate attribution to the author(s), please contact ODVA on: TEL +1 734-975-8840
FAX +1 734-922-0027 EMAIL odva@odva.org WEB www.odva.org. CIP, Common Industrial Protocol, CIP Energy, CIP Motion, CIP
Safety, CIP Sync, CIP Security, CompoNet, ControlNet, DeviceNet, and EtherNet/IP are trademarks of ODVA, Inc. All othertrademarks are property of their respective owners.

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