TIA
STANDARD ANSI/TIA-568-B.1-7-2006
Approved: January 13, 2006

Commercial Building Telecommunications
Cabling Standard

Part 1 - General Requirements

Addendum 7 – Guidelines for Maintaining
Polarity Using Array Connectors
TIA-568-B.1-7
(Addendum No.7 to TIA-568-B.1)


(From Standards Proposal No. 3-4425-AD7-C formulated under the cognizance of the TIA
TR-42.8 Subcommittee on Telecommunications Optical Fiber Cabling Systems).
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Table of Contents

FOREWORD ...................................................................................................................................iv

1

INTRODUCTION ..................................................................................................................... 1

2

SCOPE .................................................................................................................................... 2

3

CONNECTIVITY METHODS FOR ESTABLISHING POLARITY............................................ 2

3.1

General................................................................................................................................ 2

3.1.1

Descriptions................................................................................................................. 2

3.2

Connectivity Method A......................................................................................................... 3

3.2.1


4.1

General.............................................................................................................................. 13

4.2

Components for Connectivity Method A............................................................................ 14

4.2.1

Type-A Array Connector Cables and Patch Cords.................................................... 14

4.2.2

Type-A Array Adapters .............................................................................................. 14

4.2.3

Transitions ................................................................................................................. 15

4.2.4

A-to-B patch cords..................................................................................................... 16

4.2.5

A-to-A Patch cords..................................................................................................... 16

4.3


4.4.3

Transitions ................................................................................................................. 18

4.4.4

A-to-B patch cords..................................................................................................... 18

ANNEX A (INFORMATIVE) References ....................................................................................... 19
TIA-568-B.1-7
iii
List of Figures

Figure 1: Connectivity Method A for Duplex Signals.........................................................4

Figure 2: Connectivity Method A for Parallel Signals........................................................6

Figure 3: Connectivity Method B for Duplex Signals.........................................................8

Figure 4: Connectivity Method B for Parallel Signals......................................................10

Figure 5: Connectivity Method C for Duplex Signals.......................................................12

Figure 6: Type-A Array Connector Cable or Patch Cord (key-up to key-down)..............14

Figure 7: Transition.........................................................................................................15



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approved was from the contributors’ experience and the state of the art at that time.
Users are encouraged to verify that they have the latest revision of the standard. TIA-568-B.1-7
1
1 INTRODUCTION

To support bi-directional communication systems that use separate optical fibers in each
direction, the cabling system must provide correct signal polarity so that the transmitter on one
end of the channel will connect to the receiver on the other end. Maintaining the correct
transmit-to-receive polarity throughout the cabling system is critical for system operation.
Following certain cable polarity guidelines when installing the cabling system will simplify
channel connectivity.

Correct polarity is administered according to the requirements of the depicted methods.
Intermixing the components of these methods may result in incorrect polarity.

The increasing use of optical connectivity in data communications networks (particularly in
areas of highly concentrated equipment, such as data centers) is driving the need for more
compact forms of connectivity. Array connectors are one way of meeting this need. Since the
polarity requirements for array connectors extend beyond the commonly deployed duplex (A-B)

B, and C. No preference or priority is implied by this notation.

When mating connectors that use alignment pins (such as the MPO and MT-RJ) it is critical that
one plug is pinned and the other plug is unpinned. The pinned connector is typically located
inside the panel. That is, the connector that stays in place is pinned; the connector that is
frequently removed & handled is unpinned. As MT-RJ or MPO transceivers typically have pins,
this convention leads to the following implementation on initial build out:

• Patch cords from transceiver to panel are typically unpinned on both ends.
• Transitions (mounted behind the panel) are typically pinned.
• Cables from rack to rack are typically unpinned on both ends.

Array connectors can be flat or angle polished. Flat-polished connectors do not optically mate
with angle-polished connectors.

3.1.1 Descriptions

A-to-B patch cord: A duplex patch cord that connects position A on one end of the patch cord
to position B on the other end of the patch cord. See section 4.2.4.

A-to-A patch cord: A duplex patch cord that connects position A on one end of the patch cord
to position A on the other end of the patch cord. See section 4.2.5.

Array Connector: An optical fiber connector containing a single ferrule with multiple terminated
fibers arranged in a line or a series of lines.

Transition: An assembly of optical fibers and connectors, with an array connector on one end
and simplex or duplex connectors on other end.
A-to-A Patch Cord