Rockwell Automation 1786 User Manual

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Installation Instructions

ControlNet Fiber Media Planning and Installation Guide

Catalog Number

1786 Series

Important User Information

IMPORTANT

Solid-state equipment has operational characteristics differing from those of electromechanical equipment. Safety Guidelines for the Application, Installation and Maintenance of Solid State Controls (publication SGI-1.1 your local Rockwell Automation® sales office or online at http://www.rockwellautomation.com/literature/ important differences between solid-state equipment and hard-wired electromechanical devices. Because of this difference, and also because of the wide variety of uses for solid-state equipment, all persons responsible for applying this equipment must satisfy themselves that each intended application of this equipment is acceptable.

In no event will Rockwell Automation, Inc. be responsible or liable for indirect or consequential damages resulting from the use or application of this equipment.

The examples and diagrams in this manual are included solely for illustrative purposes. Because of the many variables and requirements associated with any particular installation, Rockwell Automation, Inc. cannot assume responsibility or liability for actual use based on the examples and diagrams.

No patent liability is assumed by Rockwell Automation, Inc. with respect to use of information, circuits, equipment, or software described in this manual.

Reproduction of the contents of this manual, in whole or in part, without written permission of Rockwell Automation, Inc., is prohibited.

Throughout this manual, when necessary, we use notes to make you aware of safety considerations.

WARNING: Identifies information about practices or circumstances that can cause an explosion in a hazardous environment, which may lead to personal injury or death, property damage, or economic loss.

available from

) describes some

ATTENTION: Identifies information about practices or circumstances that can lead to personal injury or death, property damage, or economic loss. Attentions help you identify a hazard, avoid a hazard, and recognize the consequence

SHOCK HAZARD: Labels may be on or inside the equipment, for example, a drive or motor, to alert people that dangerous voltage may be present.

BURN HAZARD: Labels may be on or inside the equipment, for example, a drive or motor, to alert people that surfaces may reach dangerous temperatures.

Identifies information that is critical for successful application and understanding of the product.

Allen-Bradley, Rockwell Software, Rockwell Automation, RSNetWorx for ControlNet, and TechConnect are trademarks of Rockwell Automation, Inc.

Trademarks not belonging to Rockwell Automation are property of their respective companies.

Summary of Changes

This manual contains new and updated information. Changes throughout this revision are marked by change bars, as shown to the right of this paragraph.

New and Updated Information

This table contains the changes made to this revision.

Topic Page

Updated the terminology for determining fiber topology 15 Added information for allowable ring configurations 18 Included installation procedures for fiber repeater modules and

a repeater adapter Updated status indicator descriptions for fiber repeater modules and

a repeater adapter

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 3

Summary of Changes

Notes:

4 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Preface

Get Started with the ControlNet Network Fiber Media System

Additional Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Chapter 1

Why Choose a Fiber-optic Media System?. . . . . . . . . . . . . . . . . . . . . . . . . . 11

Analyze Your Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Identify Fiber Media Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Fiber-optic Cable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Nodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Repeater Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Repeater Adapters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Determine Network Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Point-to-Point Topology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Star Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Ring Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Plan the Installation of the Fiber Media Components . . . . . . . . . . . . . . . 19

Choose the Fiber Media System Composition . . . . . . . . . . . . . . . . . . . . . . 19

Configure the Media in RSNetWorx for ControlNet Software. . . . . . . 25

Set up the Network SMAX Parameter in RSNetWorx Software . . 25

Terminate Your Fiber Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Test Your Fiber Media Connections and Segments . . . . . . . . . . . . . . . . . 26

Power Your Repeaters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Verify Your Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Topology and Signal Considerations

Chapter 2

Develop a Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Redundant Media . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Topology Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Coax Segment Constraints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Example Coax Segment Constraint . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Fiber Segment Constraints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Select a Module Type Based on Distance Requirements . . . . . . . . . . . . . 31

Simplex Cable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Duplex Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Multi-fiber Backbone Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Estimate Cable Lengths. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

1786-RPFS Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

1786-RPFM Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

1786-RPFRL/B Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

1786-RPFRXL/B (Fiber Ring or Point-to-Point) Module . . . . . . . 35

Determine Attenuation Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Attenuation Levels for a Short-distance Fiber Segment . . . . . . . . . . 35

Attenuation Levels for Medium-distance Fiber Segments . . . . . . . . 37

Attenuation Levels for Long-distance Fiber Segments . . . . . . . . . . . 38

Attenuation Levels for an Extra-long Fiber Segment . . . . . . . . . . . . . 38

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 5

Table of Contents

Guidelines for Fiber-optic Installation

Determine Propagation Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Maximum Propagation Delay Through a Network . . . . . . . . . . . . . . 39

Maximum Propagation Delay and Skew

Through a Redundant Network. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Chapter 3

General Rules and Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Hire Fiber-optic Specialists for Installation and Certification . . . . . 43

Guidelines for Handling Fiber-optic Cable. . . . . . . . . . . . . . . . . . . . . . 44

Types of Fiber Media Installations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Pulled Application Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Direct Attachment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Indirect Attachment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Conduit and Duct Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Aerial Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Direct Burial Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Open Trench Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Vertical Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Terminate Your Fiber-optic Cable

Verify Your Network

Install Your Fiber Repeater Modules and Repeater Adapters

Chapter 4

What Is Termination? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Terminate Your Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Chapter 5

Set Network Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Measure Power Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

OTDR Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Appendix A

Installation Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Mount the Fiber Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Install the Ferrites. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Connect a 1786-RPFS Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Connect Fiber Repeater Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Terminate the Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Wire a Repeater Adapter Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Troubleshoot the Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Specifications for

Fiber-optic Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

1786-RPFS Fiber-optic Cable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

1786-RPFM Fiber-optic Cable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

1786-RPFRL/B Fiber-optic Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

1786-RPFRXL/B Fiber-optic Cable. . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

6 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Appendix B

Table of Contents

Status Indicators

Glossary

Index

1786-RPFS and 1786-RPFM Status Indicators. . . . . . . . . . . . . . . . . . 76

1786-RPFRL/B or 1786-RPFRXL/B Status Indicators . . . . . . . . . . 77

1786-RPFRL/B or 1786-RPFRXL/B Relay Contact Connectors. 78

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 7

Table of Contents

Notes:

8 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Preface

IMPORTANT

This guide provides basic information for fiber cable planning and installation. Actual procedures for installing your system may vary depending on cable style and installation environment. We recommend that you consult a network design specialist for the design of your fiber network.

Additional Resources

Refer to the Glossary

for clarification of terms associated with fiber technologies.

To successfully apply the concepts and techniques contained in this manual, you must have a fundamental knowledge of electronics and electrical codes.

These documents contain additional information concerning related products from Rockwell Automation.

Resource Description

NetLinx Selection Guide, publication NETS-SG001. Describes the NetLinx-based networks—

ControlNet Media System Components List, publication AG-PA002

ControlLogix System User Manual, publication

ControlNet Modular Repeater Adapter Installation Instructions, publication 1786-IN013

ControlNet Modules in Logix5000 Control Systems User Manual, publication CNET-UM001

ControlNet IP67 Tap and Cable Assembly Kit Installation Instructions, publication 1786-IN017

ControlNet Coax Media Planning and Installation Guide, publication CNET-IN002

Industrial Automation Wiring and Grounding Guidelines, publication 1770-4.1

Product Certifications website, http://www.ab.com

1756-UM001

DeviceNet, ControlNet, and EtherNet/IP. Lists category numbers and specifications for

the components that comprise the ControlNet media system.

Describes how to use your ControlLogix operating system.

Provides instructions for installing a repeater adapter.

Describes how your Logix5000 controller communicates with different devices on the ControlNet network.

Provides installation instructions for a tap with an IP67 rating.

Describes the media that comprises a copper cable system.

Provides general guidelines for installing a Rockwell Automation industrial system.

Provides declarations of conformity, certificates, and other certification details.

You can view or download publications at http://www.rockwellautomation.com/

literature/. To order paper copies of technical documentation, contact your local

Allen-Bradley distributor or Rockwell Automation sales representative.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 9

Preface

Notes:

10 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Chapter

Get Started with the ControlNet Network Fiber Media System

Topic Page

Why Choose a Fiber-optic Media System? 11 Analyze Your Network 12 Identify Fiber Media Components 12 Determine Network Topology 15 Plan the Installation of the Fiber Media Components 19 Choose the Fiber Media System Composition 19 Configure the Media in RSNetWorx for ControlNet Software 25 Terminate Your Fiber Cable 26 Test Your Fiber Media Connections and Segments 26 Power Your Repeaters 26 Verify Your Network 26

Why Choose a Fiber-optic Media System?

This chapter is an overview of the process you need to follow when you apply fiber media. Some of the information in this chapter repeats in subsequent chapters for instructional purposes.

Fiber media holds many advantages over traditional copper media. Since fiber-optic media transmits digitized information via light pulses over glass or plastic fibers, it avoids many of the problems common with copper applications.

In certain applications, the advantages of fiber over coax media outweigh the higher cost of fiber media and components.

ATTENTION: If you are using fiber in an intrinsically safe area, consult with your local safety coordinator.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 11

Chapter 1 Get Started with the ControlNet Network Fiber Media System

Table 1 - Fiber Media Advantages

Features Benefits

Electrical isolation Fiber media is isolated from any potential electrical sources

Immunity to interference Fiber media is immune to EMI (electromagnetic interference)

Longer distances Fiber media has less transmission loss than copper media.

Decreased size and weight Fiber media is smaller and lighter than coax media for ease

Entry into hazardous areas Fiber media is a portal for information into hazardous areas,

that cause disruptions on copper media. Fiber media is well-suited for installations between buildings, and provides immunity to lightning strikes.

since it uses light pulses on glass fibers. Fiber media is effective in noisy environments (heavy machinery, multiple cable systems, and so forth) where copper could suffer disruptions. Fiber media is also suited for high-voltage environments.

The lower loss in fiber media means fewer repeaters than copper media, making fiber more effective for applications requiring long-distance media connections.

of installation.

reducing the risk of injury. For more information on choosing components for use in hazardous areas, refer to the ControlNet EX Media Planning and Installation Guide, publication CNET-IN003

Analyze Your Network

Identify Fiber Media Components

Take the time to analyze your current or new network application to see where it makes the most sense to use coax or fiber media. If you are creating a new network or adding fiber to an existing network, create a design plan for the fiber segments of your network and identify the purpose for the fiber segments.

By creating a plan and analyzing your design you will be eliminating the potential for misapplication of media. Use the example topologies to determine your network’s topology. When you understand your network’s topology it will help you determine the media components you need to achieve your application requirements.

The ControlNet network fiber media system is comprised of these components:

• Fiber-optic Cable

• Nodes

• Connectors

• Repeater Modules

• Repeater Adapters

For information on purchasing these components, see the ControlNet Media System Components List, publication AG-PA002

12 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Get Started with the ControlNet Network Fiber Media System Chapter 1

Core

Coating

Cladding

Buffer

Fiber-optic Cable

Fiber-optic cables consist of three major components, the buffer and coating, cladding, and the core.

Figure 1 - Fiber-optic Cable Components

Table 2 - Fiber-optic Cable Description

Parts Description

Buffer and coating The buffer and coating are the material that surround the glass fiber.

Cladding The cladding is a material that provides internal reflection so that the

Core The core is the cylinder consisting of glass fiber that carries

They are responsible for protecting the fiber strands from physical damage.

light pulses can travel the length of the fiber without escaping from the fiber.

information in the form of light pulses.

Nodes

A network is a collection of segments with nodes connected together by repeaters. A node is any physical device connecting to the ControlNet fiber or ControlNet media system that requires a network address to function on the network.

Connectors

Fiber cable connectors connect fiber cable to the fiber repeater module. The medium, long, and extra-long distance fiber repeater modules use an ST-type connector and the short-distance fiber repeater modules use a V-pin type connector. The short-distance fiber cables come factory terminated in various lengths. You can increase the distance of the network by using low loss cable and connectors.

See page 33

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 13

for more information.

Chapter 1 Get Started with the ControlNet Network Fiber Media System

IMPORTANT

Repeater Modules

There are two types of repeater modules: coax repeater (catalog number 1786-RPCD) and fiber repeaters (catalog numbers 1786-RPFS, 1786-RPFM, 1786-RPFRL/B, and 1786-RPFRXL/B). Although you can repeat coax signals on a network by using a 1786-RPCD module, this manual mainly focuses on fiber cabling for the fiber repeater modules.

See the ControlNet Coax Media Planning and Installation Guide, publication

CNET-IN002

, for more information on ControlNet copper networks.

The fiber repeater modules send an optical signal through the fiber cable to the next fiber repeater module on the network. The combination of the repeater adapter (see below) and a fiber repeater module, such as the 1786-RPFM, is referred to as a fiber repeater.

Repeater Adapters

The ControlNet network uses a modular fiber repeater system. The 1786-RPA/B repeater adapter connects to both coax and fiber media, supplies power to the repeater modules, and repeats signals from the coax media to the fiber repeater modules.

The repeater adapter can supply a maximum of 1.6 A @5V DC of current to power the repeater modules.

To determine how many repeater modules you can use with a single repeater adapter, calculate the current draw of all repeater modules in your system. Do not exceed 1.6 A @ 5V DC per repeater adapter.

Table 3 - Repeater Module Current Draw

Repeater Module Backplane Current Draw

1786-RPFS 300 mA 1786-RPFM 400 mA 1786-RPFRL/B 570 mA 1786-RPFRXL/B 570 mA 1786-RPCD 400 mA

The 1786-RPFRL/B and 1786-RPFRXL/B repeater modules require 570 mA each, therefore you can attach only two of these modules to a 1786-RPA/B repeater adapter.

Regardless of repeater module current draw, you are limited to a

maximum of four repeater modules per repeater adapter.

14 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Get Started with the ControlNet Network Fiber Media System Chapter 1

CR N

41326

Network

Coax Segment Coax Segment

Coax Segment

TTTTTTTTT

TTTTT

NNNNNN

NN DN

FR FR

TR TR TR

TR TR

Trunk Line Drop Line

Fiber segment to isolate or extend a segment

45635

Determine Network Topology

Item Term Description Item Term Description

Passive tap with drop cable

Node or device

Terminator (dummy load)

The connection between any device and the cable system. The length of the drop cable is 1 m (3.28 ft).

Any physical device connecting to the ControlNet network cable system that requires a network address to function on the network.

Terminates a tap drop cable that has yet to be connected to a node to help prevent noise on the line.

We suggest that you take sufficient time to plan the installation of your network before assembling any components. The table defines some of the basic ControlNet network terminology used in example topologies.

Coax repeater

Fiber repeater

Terminating resistor

An active physical layer component that reconstructs and retransmits all traffic it hears on one coax segment to another coax segment.

An active physical layer component that reconstructs and retransmits all traffic it hears on one fiber segment to another fiber segment. A coax port on the repeater adapter is available to relay the fiber traffic to the coax segment.

A 75 Ω resistor mounted in a BNC plug to absorb electrical energy of the signal at the end of the cable to prevent reflections. Each end of a segment must be terminated.

The illustration describes an example trunk line topology.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 15

Chapter 1 Get Started with the ControlNet Network Fiber Media System

Coax Segment 1 Coax Segment 2 Coax Segment 3

Fiber Cable 1 Fiber Cable 2 Fiber Cable 3

See Important below

IMPORTANT

You can configure these topologies on a ControlNet network:

• Point-to-Point Topology

• Star Topology

• Ring Topology

Point-to-Point Topology

Point-to-point is also called a bus or a trunk line topology. A point-to-point topology can be described as one fiber module transmitting to another module. For example, you cannot transmit from a medium-distance module to a short-distance module.

Figure 2 - Example Point-to-Point (Trunk Line) Topology

It is not necessary to install nodes on coax segments. If you are using only the repeaters to extend the network, install a 75(catalog number 1786-XT) on the BNC coax connector on the 1786-RPA/B repeater adapter or 1786-RPCD module. This should be done to all repeater modules that are not connected to coax segments.

16 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Ω terminator

Get Started with the ControlNet Network Fiber Media System Chapter 1

31238-M

See Important on page 16

Star Topology

In a star topology, all segments of the fiber network start from a central location.

Figure 3 - Star Topology

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 17

Chapter 1 Get Started with the ControlNet Network Fiber Media System

Up to 20 1786-RPFR(X)L repeaters on a fiber ring.

iber

ber

Node(s)

RPA + RPFRXL

Coax

Coax Network

Ring Topology

A ring topology provides redundancy by providing two data paths in a single ring. A ring can sustain two faults before that data connection is lost. You should consider a ring when your devices (Controller and I/O) are single port (A only) and media redundancy is required. Only the 1786-RPFRL and 1786-RPFRXL repeater modules support ring topologies.

In a ring topology on the ControlNet network, you can use:

• Up to 5 repeaters by using one 1786-RPA/A repeater adapter.

• The 1786-RPA/B repeater adapter allows for a maximum of 20

1786-RPFRL (long distance) or 1786-RPFRL/X (extra long-distance) ring repeaters.

Figure 4 - Ring Topology

If a ring is broken, the configuration then becomes a linear bus and the number of repeaters in SERIES depends on where the ring is broken. You will have as many repeaters as in the original ring.

18 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

See page 29

to determine different topology constraints.

Get Started with the ControlNet Network Fiber Media System Chapter 1

TIP

Plan the Installation of the Fiber Media Components

Choose the Fiber Media System Composition

During the planning phase of your network design, create checklists to help you determine the following components that are needed in an application:

• Number of nodes in your network

In a network containing a fiber repeater module, such as a 1786-RPFRL/B or 1786-RPFRXL/B module, you cannot have more than 98 node addresses assigned.

• Length of the fiber segments

• Number of fiber connectors and splices in your network

• Calculate the maximum allowable segment length

• Any additional repeaters and coax segments you need

The fiber repeater consists of the following:

• A 1786-RPA repeater adapter

• Up to two 1786-RPFRL/B (long-distance) or 1786-RPFRXL/B (extra-long distance) fiber repeater modules

• Up to four 1786-RPFS (short-distance) or 1786-RPFM (medium-distance) fiber repeater modules

It is allowable to mix these repeater modules on a single repeater adapter.

Refer to Table 3 on page 14 connect to one repeater adapter. The number of repeaters and the total cable length depends on your network topology limits and the repeater modules you select.

to determine how many repeater modules you can

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 19

Chapter 1 Get Started with the ControlNet Network Fiber Media System

You can use fiber repeaters for these tasks:

• Extend the total length of your segment (point-to-point or trunk line topology)

• Create star and ring configurations (multiple directions from one point)

• Cross into hazardous areas

When you configure your network by using fiber repeaters, you can install them in one of the following ways:

Fiber Repeater Installation Page

Series 21 Parallel 22 Combination of series and parallel 23 Ring (only fiber) 24

ATTENTION: In hazardous areas, you must use products specifically designed for that purpose. You can use fiber repeaters that are designed for hazardous areas as a link from your non-hazardous area to your hazardous area.

For hazardous locations, consult the ControlNet EX Media Planning and Installation Manual, publication CNET-IN003

ATTENTION: The maximum distance in the network is limited by the distance between the two nodes farthest from one another, and the number of repeaters.

20 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Get Started with the ControlNet Network Fiber Media System Chapter 1

Node 1

Node 2 Node 3

Repeater A

Coax Segment 1

Coax Segment 2

Coax Segment 4

Coax Segment 3

Repeater B Repeater C

Node 4

Node 5

Node 6

42306

Fiber Cable 1 Fiber Cable 2

1786-RPA1786-RPA

1794-ACNR15

1786-RPFM 1786-RPFM

1786-RPCD

* See Important on page 16

1786-RPA 1786-RPFM

1794-ACNR15

Install Repeaters in a Series

Series is defined as the number of repeater assemblies (repeater adapter plus fiber repeater module) between two devices on a network repeaters in a series, use the RSNetWorx™ for ControlNet™ software to verify that the system is an allowable configuration. The system size is based on the maximum number of repeaters in a series and maximum length of the media used between any two nodes.

When you install repeaters in series, you can install a maximum of:

• 5 repeater modules (or 6 segments) with a 1786-RPA/A series A repeater adapter

• 20 repeater modules (or 21 segments) with a 1786-RPA/B series B repeater adapter

Figure 5 - Fiber Repeaters in a Series

. When you install fiber

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 21

In Figure 5, the maximum number of fiber repeaters is 3, because a message from coax segment 1 to coax segment 2 travels through 3 repeaters in series (A, B, and C).

For any given architecture, the highest number of repeaters that a message might travel through to get from any single node to another determines the number of repeaters in a series.

Chapter 1 Get Started with the ControlNet Network Fiber Media System

42307

Coax Segment 1 Coax Segment 2 Coax Segment 3

Node 1

Node 2 Node 3

Repeater A Repeater B Repeater C Repeater D

1786 -RPA 1786 -RPA 1786 -RPA 1786 -RPA1786-RPFM 1786-RPFM 1786-RPFM 1786-RPFM

1794-ACNR15

Fiber Cable 1

Fiber Cable 2

Install Repeaters in Parallel

When you install repeaters in parallel, you can install a maximum of 48 repeaters (the maximum number of taps per 250 m segment). Figure 6 fiber repeaters being used in parallel.

Figure 6 - Fiber Repeaters in Parallel

shows an example of

Fiber repeaters A and B are in parallel off of coax segment 1. The network example shows 2 fiber repeaters in series. This is determined by counting the number of fiber repeaters a message must travel through to get from one node to another. For example, if a message travels from node 1 to node 2 (B, C) or from node 1 to node 3 (A,D), it travels through 2 fiber repeaters.

22 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Get Started with the ControlNet Network Fiber Media System Chapter 1

31509-M

Coax Segment 7

Repeaters D, E and F are installed in parallel

Repeater D

Coax Segment 1 Coax Segment 2 Coax Segment 3

Repeater E Repeater F

Node 1 Node 2 Node 3

Repeater A Repeater B Repeater C

Coax Segment 4 Coax Segment 6

Node 4 Node 6

Repeaters A, B, and C are installed in series and connected to the repeaters in parallel on segment 7 via Repeater F

Node 5

Coax Segment 5

Fiber Cable 1

Fiber Cable 2

Fiber Cable 3

** *

See Important on page 16

Install Repeaters in a Combination of Series And Parallel

You can install repeaters in a combination of series and parallel connections. For mixed topologies (series and parallel) the maximum number of repeaters in series between any two nodes is 20.

• If you configure your network by using repeaters in combination of series and parallel, you need to count the repeaters in series on the worst-case path between any two nodes.

• There can be only one path between any two nodes on a ControlNet network link. Multiple repeater connections between two segments are not allowed.

Figure 7 - Repeaters in a Combination of Series and Parallel

In this network example, the maximum number of repeaters that a message will travel through is 5. The path is as follows: Node 1 to Node 4 travels through repeaters D, F, C, B, A. Repeaters D and E are in parallel, so you must consider the path of Node 2 to Node 4 through repeaters E, F, C, B, A. This secondary path is dependant on the fiber and coax lengths of Segment 1 and Segment 2, including Segment 7.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 23

Chapter 1 Get Started with the ControlNet Network Fiber Media System

Node 1

Node 2

Node 3

Node 4

31237-M

1794-ACNR15 1786-RPA 1786-RPFRXL

1786-RPA

1786-RPFRXL

1794-ACNR15

Repeater A

Repeater B

Repeater C

Repeater D

Fiber Cable 1

Fiber Cable 2

Coax Segment 1

Coax Segment 2

Coax Segment 3

Coax Segment 4

Fiber Cable 3

Fiber Cable 4

Install Repeaters in a Ring

Use this configuration to achieve an increased level of protection (in case of cable failure) over a long distance (not available when you use traditional copper media). To achieve this increased level of protection, a fiber ring network transmits messages in the two directions of the ring (clockwise and counter-clockwise).

In Figure 8

, the path from node 1 to node 4 in a counter-clockwise direction is through 2 fiber repeaters (A, D). In a clockwise direction, the path from node 1 to node 4 is though 4 fiber repeaters (A, B, C, D). We refer to the longer path as the worst-case delay path.

Figure 8 - Fiber Repeaters in a Ring

The 1786-RPFRXL/B and 1786-RPFRL/B fiber repeaters automatically detect which message arrives first and disregards the other at each fiber repeater location. In the above example, the 1786-RPFRXL fiber repeater for node 4

24 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

would automatically detect the packet that arrives on a channel first, and disregard the second packet.

Get Started with the ControlNet Network Fiber Media System Chapter 1

IMPORTANT

A fiber-optic ring may contain up to 20 1786-RPFRL/B (long distance) or 1786-RPFRXL/B (extra-long distance) fiber repeaters, depending on the application.

When used in a ring topology, redundant coaxial cabling (linear bus) or redundant rings are not allowed. Due to timing differences, the 1786-RPFRXL/B and 1786-RPFRL/B fiber modules do not support redundant rings.

Configure the Media in RSNetWorx for ControlNet Software

You can use RSNetWorx for ControlNet software to determine whether or not your system meets the network parameter requirements. Based on your system planned requirements (NUT, SMAX, UMAX, types and length of cable, number and types of repeaters and worst case network delay), RSNetWorx software will verify the network configuration parameters.

If RSNetWorx is unable to schedule the network due to errors, make the necessary changes. Changes might include inserting the correct media lengths and number of repeaters or increasing RPI, so the software can calculate the correct network parameters and download them to the keeper.

Set up the Network SMAX Parameter in RSNetWorx Software

You must properly set up the SMAX parameter in RSNetWorx for ControlNet software when used with the 1786-RPFRL or 1786-RPFRXL repeater module. The SMAX parameter sets the maximum scheduled node address on a ControlNet network. Refer to the documentation supplied with the RSNetWorx for ControlNet software.

You must set the SMAX parameter at least one node number higher than the highest-used scheduled node number. For example, on a network with 49 scheduled nodes (with 49 being the highest-used scheduled node number), you must set SMAX to at least 50. In this example, node number 50 is an unused scheduled node number.

When setting the SMAX parameter, you must allow one unused scheduled node address. This unused node address must be the highest available scheduled node number. Therefore, the maximum usable node address when using the 1786-RPFRL/B or 1786-RPFRXL/B module is 98.

For more information, see Getting Results with RSNetWorx for ControlNet, publication CNET-GR001

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 25

Chapter 1 Get Started with the ControlNet Network Fiber Media System

Terminate Your Fiber Cable

Test Your Fiber Media Connections and Segments

Power Your Repeaters

Be sure to use the correct connectors on the end of your fiber cable for the best optical and mechanical connections. For example, ST- and V-pin are the only two connectors that the ControlNet network recognizes.

See Tab le 8 o n pa ge 5 4 repeater modules.

You also want to use a dust cap on an unconnected terminated fiber cable end if a connector is not going to be used.

Many field testers are available to test the connectors on cable that is used with the 1786-RPFM, 1786-RPFRL/B and 1786-RPFRXL/B repeater modules. Consult with your fiber network specialist to determine which tester is the best for your media.

The power for your fiber repeaters comes from the repeater adapters. The repeater adapters must be powered by using a 24V power supply.

See page 68 power supply requirements.

for the 1786-RPA/B repeater adapter installation instructions and

for more information on available connector kits for

Verify Your Network

Verify whether your system meets the network parameter requirements.

1. In RSNetWorx for ControlNet software, go online, browse your network, and look for invalid node addresses.

2. OTDR and fiber field testers will help make sure that no segments violate distance constraints.

3. Make sure your network does not violate general network rules.

See Chapter 3, starting on page 43

4. Isolate a single segment of the network and verify its operation.

5. Connect multiple segments of the network , being mindful of bandwidth,

insertion loss of the segment, and segment length.

6. Verify that the correct connectors and cable have been installed.

See page 55

for additional information.

, for details.

26 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Chapter

Topology and Signal Considerations

Topic Page

Develop a Plan 27 Redundant Media 28 Topology Considerations 29 Coax Segment Constraints 30 Fiber Segment Constraints 31 Select a Module Type Based on Distance Requirements 31 Estimate Cable Lengths 33 Determine Attenuation Levels 35 Determine Propagation Delay 38

Develop a Plan

Fiber-optic links in a ControlNet network system can do the following:

• Increase network length beyond that supported by coax

• Provide immunity to EMI

• Provide better electrical isolation than standard coax cable

Fiber is strongly recommended to avoid lighting problems when connecting equipment in different buildings together.

You can create point-to-point, star, and ring configurations. Up to four fiber modules, with two fiber ports each, can be directly plugged to a repeater adapter. Multiple repeater adapters can be used to increase the number of fiber or coax connections.

Each port needs two fiber connections, one for receiving and another for transmitting signals. The basic configuration connects two coax segments point-to-point by two repeater adapters and two fiber repeater modules, as illustrated in Figure 9

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 27

Chapter 2 Topology and Signal Considerations

Tap

Coax Segment 1

Fiber Repeater Module

30688-M

Fiber Repeater Module

Repeater Adapter

Coax Segment 2

Terminator

Fiber Cable

TIP

Figure 9 - Basic Fiber Media Topology

Redundant Media

This configuration is equivalent to the use of a coax repeater. Fiber cable can provide communication over longer distances than coax media.

Use redundant media when you need module and media redundancy. With redundant media, the channel-to-channel skew travel time difference must be less than 1.6 μs.

To keep skew time to a minimum, configure the cable paths on channels A and B in a similar manner as shown in Figure 10 on page 29

Media redundancy can be achieved via a ring topology or linear bus topology.

The 1786-RPFRL/B and 1786-RPFRXL/B fiber repeaters can provide media redundancy in a ring or linear bus topology, but not both. A redundant linear bus topology can be obtained by using the 1786-RPFS, 1786-RPFM, and 1786-RPCD repeater modules. The planning phase should consider the advantages and disadvantages of using a ring or redundant linear bus topology.

If you use a ring topology to provide media redundancy, you can connect to only one channel (A or B) of redundant port modules. ControlNet does not support mixed (linear and ring) redundancy in the same network. When using linear bus redundancy all ControlNet modules must have redundant ports (A and B) and must be connected throughout the network.

28 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Topology and Signal Considerations Chapter 2

31420-M

For redundancy, you should do the following on each channel:

• Use the same number and types of repeater assemblies (repeater adapters plus repeater modules)

• Use the same type of cable

• Keep cable lengths similar

• If using redundant media in a linear bus topology, ring topologies are

not supported.

Figure 10 - Redundant Topology

Topology Considerations

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 29

For best results, determine the constraints of your topology. For example, a maximum of 99 nodes are allowed on a network (98 nodes if you are using ring redundancy).

Table 4 - Topology constraints

Constraint Example

Only one path is allowed between nodes (non-ring repeater modules only)

In series topology, maximum of 20 repeaters in a series In ring topology, up to 20 1786-RPFRL/B or 1786-

RPFRXL/B modules per ring Constraint of each coax segment (taps and trunk-cable

sections) Constraint of each fiber segment application See page 31. Power loss budget of each fiber segment See Table 5 on page 33 Maximum propagation delay through the network See page 39

See Figure 7 on page 23.

See Figure 5 on page 21 See Figure 8 on page 24

See Figure 11 on page 30.

Chapter 2 Topology and Signal Considerations

1000 (3280)

750 (2460)

500 (1640)

250 (820)

Maximum Allowable Segment Length = 1000 m (3280 ft) - 16.3 m (53.4 ft) x [number of taps - 2]

Number of Taps

)

30014-m

Allowable Region

2163264

500 (1640)

EXAMPLE

Coax Segment Constraints

The total allowable length of a segment containing standard RG-6 quad shield coaxial cable depends upon the number of taps in your segment. There is no minimum trunk-cable section length requirement.

The maximum allowable total length of a segment is 1,000 m (3280 ft) with two taps connected. Each additional tap decreases the maximum length of the segment by 16.3 m (53 ft).

The maximum number of taps allowed on a segment is 48, with a maximum length of 250 m (820 ft).

Figure 11 - Maximum Segment Length (Using 1786-RG6 Coax Cable)

The data in Figure11 assumes you are using standard low-loss coax. High-flex cable may not support the distance versus the number of taps due to the higher loss factor associated with high-flex designs.

30 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Example Coax Segment Constraint

If your segment requires 10 taps, the maximum segment length is: 1000 m (3280 ft) - 16.3 m (53.4 ft) x [10 - 2] 1000 m (3280 ft) - 130.4 m (427.2 ft) = 869.6 m (2852.8 ft) The total trunk-cable length or number of taps can be increased by

installing repeaters on the segment. This creates another segment. The amount of high-flex RG-6 cable (catalog number 1786-RG6F) you can

use in a system is less than the amount of standard RG-6 cable, so you should keep high-flex cable use to a minimum. Use BNC bullet connectors to isolate areas that require high-flex RG-6 cable from areas that require standard RG-6 cable; this allows the high-flex RG-6 section to be replaced before flexture life is exceeded.

For more information in the installation of a coax segment, see publication

CNET-IN002

, ControlNet Coax Media Planning and Installation Guide.

Topology and Signal Considerations Chapter 2

IMPORTANT

31506-M

Fiber Segment Constraints

Select a Module Type Based on Distance Requirements

Every network that uses fiber repeaters must maintain a minimum signal level for each fiber segment in order to achieve an effective signal strength. Attenuation of a fiber segment is effected by the quality of the termination at each connector, splices, bulkheads, and the fiber cable. At any time, the total amount of attenuation shall not exceed the power budget of the type of repeater module that is being used.

The attenuation values for connectors, splices, bulkheads, and cable are available in the manufacturer’s specifications for your products.

When choosing a module type to use in a configuration, a commonly asked question is ‘Can I use a particular cable with a particular module?’ You must select a module (and the corresponding cable type) based on the distance you want to achieve.

There are two types of fiber cable supported: single and multi-mode. These two cable types differ in that single-mode cable allows light to travel in a single path. Multi-mode cable allows light to travel in multiple paths. Single-mode cable is generally used in longer distance applications.

Of these two types of cores, there are three configurations of cable commonly found in manufacturing environments:

• Simplex Cable

• Duplex Cable

• Multi-fiber Backbone Cable

All three cable configurations have either single- or multi-mode cores.

Simplex Cable

At each end, the cable is terminated with a connector appropriate to the type of fiber module to which the cable is attached.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 31

Chapter 2 Topology and Signal Considerations

31507-M

31508-M

Duplex Cable

A duplex cable is made up of two jacketed fiber cores, with their jackets fused together to form a single cable. A duplex cable is sometimes called a zipcord fiber jumper.

Smaller lengths of simplex and duplex interconnect cable are typically directly connected between modules, or to a fiber panel within an enclosure.

Multi-fiber Backbone Cable

Multi-fiber backbone cable is composed of many fiber cores bundled into a jacketed cable. These cables are often run to a fiber panel within an enclosure. Smaller lengths of simplex or duplex interconnect cable are then typically used to connect from the fiber panel to individual modules or networks.

What is Zipcord?

The term ‘zipcord’ refers to any cable that is a duplex cable whereby the jacket is fused together to form a lamp cord-like cable that can be easily parted. The V-pin connector makes sure the fiber is reversed on opposite ends of the cable so that the Transmit end from one module is automatically connected to the Receive end of the other module.

Multiple lengths of zipcord (catalog number 1786-FSxx) are available for use with the 1786-RPFS module.

See page 65

32 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

for connection instructions.

Topology and Signal Considerations Chapter 2

Estimate Cable Lengths

The maximum length of a fiber cable section for the fiber-optic modules is dependent on the quality of the fiber, number of splices, and the number of connectors.

If your distance requirements are less than 300 m, you can use a short-distance (single-mode) cable that comes pre-terminated for use with the 1786-RPFS fiber module. If your distance requirements are greater than 300 m, you must use a 1786-RPFM, 1786-RPFRL/B, or 1786-RPFRXL/B fiber module and terminate the cables in the field, or purchase pre-terminated cables from your supplier.

When estimating maximum cable length, take into account attenuation that occurs along the entire fiber path. Attenuation refers to the loss of light power as it passes through the cabling components.

Table 5 - Fiber Module Distance and Ratings

Module Typical Repeater Distance

1786-RPFS 0…300 m 200/230 micron, single-mode

1786-RPM 0…3 km 62.5/125 µm, multi-mode

1786-RPFRL/B 0…10 km 62.5/125 µm, multi-mode

1786-RPFRXL/B 0…20 km 62.5/125 µm, multi-mode

(1)

Cable Type Optical Power Budget Connector Type

650 nm

1300 nm, graded index

1300 nm, graded index 9/125 µm, single-mode

1300 nm

(3)

4.2 dB V-pin

13.3 dB ST (plastic or ceramic only; do

15 dB

(2)

10.5 dB

not use metal connectors)

(1) Entire network limited to 20 km max, per ControlNet network specifications.

(2) Although you can use multi-mode cable with the 1786-RPFRXL/B module, it is not recommended because achieveable distance is limited to 6.6 km.

(3) Also compatible with 62.5/125

µm, multi-mode cable.

Typically cable attenuation for multi-mode fiber at a wavelength of 1300 nm is less than 1.5 dB/km, and connection losses are 1 dB per connection.

IMPORTANT

Avoid lengthening your cable by joining sections with connectors. Connectors can cause c

onsiderable attenuation and limit the maximum length of your system. Be sure to check the attenuation of different cable sections after the cable is installed.

Each Rockwell Automation fiber system has different constraints; therefore maximum fiber-optic cable lengths differ for each system. Rockwell Automation offers four different systems that are targeted to solve different applications:

• 1786-RPFS: Short-distance fiber system

• 1786-RPFM: Medium-distance fiber system

• 1786-RPFRL/B: Long-distance fiber system

• 1786-RPFRXL/B: Extra-long distance fiber system.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 33

Chapter 2 Topology and Signal Considerations

1786-RPFS Module

The 1786-RPFS (0…300 m) module specializes in solving short-distance applications. This system requires the use of pre-terminated cable assemblies. The total attenuation for a fiber cable section must be less than 4.2 dB.

200/230 Micron HCS (hard-clad silica) Fiber

Use 200 micron HSC cable with the 1786-RPFS module for short-distance applications. The 200 hcs cable is also known as a step index multi-mode type of fiber cable.

1786-RPFM Module

The 1786-RPFM (0…3 km) module is designed to solve medium-distance applications that require less than 3000 m per segment (9843 ft) between two ControlNet fiber repeaters. You must terminate medium-distance cable in the field.

The maximum length of a section is dependent on the quality of the fiber, number of splices, and the number of connectors. The total attenuation for a cable section must be less than 13.3 dB.

62.5/125 Micron multi-mode OM1 Fiber

Use 62.5/125 micron cable with the 1786-RPFM, 1786-RPFRL/B, and 1786-RPFRXL/B module for medium-distance applications. The OM1 cable is a graded index multi-mode type of fiber cable.

1786-RPFRL/B Module

The 1786-RPFRL/B (0…10 km) module is designed to solve long-distance applications that require up to 10,000 m (32,810 ft) between two ControlNet network devices. You must terminate long-distance cable in the field.

The maximum length of a section is dependent on the quality of the fiber, number of splices, and the number of connectors. The total attenuation for a cable section must be less than 15 dB.

62.5/125 Micron multi-mode OM1 Fiber

Use 62.5/125 micron cable with the 1786-RPFM, 1786-RPFRL/B, and 1786-RPFRXL/B modules for long-distance applications. The OM1 cable is a graded index multi-mode type of fiber cable.

34 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Topology and Signal Considerations Chapter 2

1786-RPFRXL/B (Fiber Ring or Point-to-Point) Module

The 1786-RPFRXL (0…20 km) module is designed to solve extra-long distance applications that require up to 20,000 m (65,620 ft) for single-mode fiber between two ControlNet network devices. You must terminate extra longdistance cable in the field.

The maximum length of a section is dependent on the quality of the fiber, number of splices, and the number of connectors. The total attenuation for a cable section must be less than 10.5 dB. This applies to single- or multi-mode fiber.

62.5/125 Micron multi-mode OM1 Fiber

Use 62.5/125 micron cable with the 1786-RPFM, 1786-RPFRL/B, and 1786-RPFRXL/B modules for extra-long distance applications. The OM1 cable is a graded index multi-mode type of fiber cable.

9/125 Micron single-mode OS1 Fiber

Determine Attenuation Levels

Use 9/125 micron with the 1786-RPFRXL/B module to achieve distances of up to 20 km. The OS1 cable is a graded index single-mode type of fiber cable.

You must calculate the power budget for you fiber cable. The short-distance fiber cable is pre-terminated; therefore the maximum attenuation level is 4.2 dB.

Once you start modifying the lengths of the segment, installing bulkhead or fusion splices, installing longer distances, exposing the cable to temperature ranges, or employing different quality cable and connector types, you must determine your attenuation levels. The following examples provide you with a place to start when you begin to determine your attenuation levels.

Attenuation Levels for a Short-distance Fiber Segment

The fiber cabling path loss can be verified by using the appropriate field test equipment. You must test the cable using the same wavelength as the specific fiber module in use.

The power budget for the short-distance fiber repeater module is 4.2 dB. This means that the maximum amount of attenuation between the two repeater modules shall not exceed 4.2 dB. This power budget is valid throughout the operating temperature range (0…60 C° (140 °F)).

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 35

Chapter 2 Topology and Signal Considerations

31505-M

Connector 1 = Fiber Connector (Each Fiber Connector is 1.5 dB)

Fiber Cable 1 = Short Distance Fiber Cable Measured @ .1 dB)

Connector 1 + Fiber Cable 1 + Connector 2 = Total Attenuation

1.5 + .1 + 1.5 = 3.1 dB

Connector 2 = Fiber Connector (Each Fiber Connector is 1.5 dB

You can also affect the power budget by the quality of the connectors and fiber cable you choose. If you use a high-quality connector and fiber cable, you will be able to stretch your power budgets. Higher-quality connectors and cable can withstand a broader range of temperatures and distances.

In most situations you will not have to determine the attenuation levels for short-distance fiber cable. The cable comes pre-terminated with connectors with the proper length of cable to be used under the maximum attenuation levels. If you modify the cables with splices then you must calculate the attenuation levels.

Figure 12

is an example of determining the maximum distance between two fiber repeaters. These are measured path losses, not theoretical. If the system attenuation exceeds the power budget, you will need to add additional repeaters.

Figure 12 - Maximum Distance Between Two Repeater Modules

Step 1: Total your loss budget

With the type of fiber module selected, how much total loss (dB) can you have?

4.2 dB on the 1786-RPFS module

Step 2: Subtract loss for connectors

Select connectors. You need to account for at least two connectors per fiber cable segment.

Loss per connector x 2 connectors (1 at each end)

2 (1.5 dB) = 3 dB

36 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Topology and Signal Considerations Chapter 2

IMPORTANT

Step 3: Subtract loss for cable lengths

Select fiber cable and identify loss = length of cable x (loss due to fiber cable/km)

Measured @ .1 dB

Step 4: Compare losses

Compare the sum of losses in steps 2 and 3, with total power budget in step 1.

4.2 dB - 3 dB - .1 dB = 1.1 dB

If the sum of steps 2 and 3 are equal to or less than step 1 (which applies for our example), then you are within the power budget.

If steps 2 and 3 are greater than step 1, then you will need to reconfigure the topology, shorten cable lengths, or re-calculate the loss budget.

Due to possible fiber connector degradation, it is recommended that an allowance of 0.5 …1.0 dB per short-distance fiber cable segment be added to the total attenuation. In the above example, the maximum cable length would be 20…70 meters.

There is no minimum length of cable for the short-, medium-, or longdistance fiber repeaters.

Attenuation Levels for Medium-distance Fiber Segments

The power loss budget for the medium-distance fiber repeater (catalog number 1786-RPFM) is 13.3 dB. The maximum amount of attenuation between the two fiber repeaters shall not exceed 13.3 dB. This power loss budget includes the entire bulkhead/fusion splice.

This power loss budget is valid throughout the operating temperature range (0…60° C) of the 1786-RPFM module.

Due to possible fiber connector degradation, it is recommended that an allowance of 1.0 dB per 62.5/125 multi-mode cable segment be added to the total attenuation.

There is no minimum length of cable for the short-, medium- or longdistance fiber repeaters.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 37

Chapter 2 Topology and Signal Considerations

Attenuation Levels for Long-distance Fiber Segments

The power loss budget for the long-distance fiber repeater (catalog number 1786-RPFRL) is 15 dB. The maximum amount of attenuation between the two fiber repeaters shall not exceed 15 dB. This power loss budget includes the entire bulkhead/fusion splice.

Attenuation Levels for an Extra-long Fiber Segment

The power loss budget for the extra-long distance fiber repeater (catalog number 1786-RPFRXL) is 10.5 dB. The maximum amount of attenuation between the two fiber repeaters shall not exceed 10.5 dB. This power loss budget includes the entire bulkhead/fusion splice.

Determine Propagation Delay

The ControlNet network maximum propagation delay specification refers to the worst-case signal delay between any two nodes on a network. You need to figure out the worst-case scenario based on distances and the number of repeaters through which the signal has to travel.

Network delays include the delays through coax and fiber media, coax repeaters, repeater adapters, and fiber modules.

In order for a network to operate, the sum of the network’s delays must be equal to or less than the maximum propagation delay of 121 μs. The total network allowable delay each way is 121 μs.

Table 6 - Delay Values for ControlNet Network Media

ControlNet Network Items Delay Values

1786-RPCD 100 ns 1786-RPA/B 901 ns 1786-RPFS 94 ns 1786-RPFRL/B 420 ns 1786-RPFRXL/B 420 ns 1786-RPFM 153 ns Coax cable 4.17 ns/meter

62.5/125 micron fiber 5.01 ns/meter 200 micron fiber 9/125 micron fiber

38 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Topology and Signal Considerations Chapter 2

31417-M

Delay 2 Delay 4 Delay 6 Delay 8

Delay 3

Delay 1

Delay 5 Delay 7

Channel A

Node 1

Node 3 Node 2

750 m

1000 m

3000 m 100 m

Delay 9

20 m

IMPORTANT

Maximum Propagation Delay Through a Network

Figure 13 is an example of a maximum propagation delay through a network.

Figure 13 - . Calculating the Delays

The example has the following maximum delay path from node 1 to node 2, end to end.

Cable delays through taps are minimal and can be ignored.

Delay Path 1: From controller to repeater adapter

Delay 1: 750 m coax cable x 4.17 ns/m = 3127 ns

Delay Path 2: 1786-RPCD module

Delay 2: Coax repeater; 901 ns (1786-RPA/B module) + 100 ns (1786-RPCD module) = 1001 ns

Delay Path 3: 1000 m of coax cable

Delay 3: 1000 m coax cable x 4.17 ns/m = 4170 ns

Delay Path 4: Fiber repeater; 1786-RPA/B module and 1786-RPFM module

Delay 4: Fiber repeater; 901 ns (1786-RPA/B module) + 153 ns (1786-RPFM module) = 1054 ns

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 39

Chapter 2 Topology and Signal Considerations

IMPORTANT

Delay Path 5: 3000 m of 62.5 micron fiber cable

Delay 5: 3000 m fiber cable x 5.01 ns/m = 15030 ns

Delay Path 6: Fiber modules; 1786-RPFM, 1786-RPA/B, 1786-RPFS modules

Delay 6: 153 ns (1786-RPFM module) + 901ns (1786-RPA/B module) + 94 ns (1786-RPFS module) = 1148 ns

Delay Path 7: 100 m of 200 micron fiber cable

Delay 7: 100 m fiber cable x 5.01 ns/m = 501 ns

Delay Path 8: Fiber modules; 1786-RPFS and 1786-RPA/B modules

Delay 8: 94 ns (1786-RPFS module) + 901 ns (1786-RPA/B module) = 995 ns

Delay Path 9: 20 m of coax cable

Delay 9: 20 m coax cable x 4.17 ns/m = 83 ns

Tot al de la y = 27109 ns (27.1 μs)

This is a valid network because the calculated propagation delay of 27.1 μs is less than the maximum allowable propagation delay of 121 μs.

Maximum Propagation Delay and Skew Through a Redundant Network

For redundant networks, not only do you have to calculate the worst-case path delay between two nodes, but you also must calculate the worst-case delay skew between channel A and channel B of the network.

The worst-case skew between redundant paths shall be less than or equal to 1.6 µs.

The following example (that uses the cable lengths in Figure 14 redundant network with these conditions:

• Node 1 and Node 2 are separated by four fiber repeaters in series on both A and B channels

) depicts a

• Channel A uses 3600 m fiber segments total versus 3300 m fiber segments total on channel B. Channel A uses 1520 m of coax cable total versus 1770 m of coax cable total on channel B.

40 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Topology and Signal Considerations Chapter 2

31417-M

Delay 2 Delay 4 Delay 6 Delay 8

Delay 1

Delay 3

Delay 5 Delay 7

500 m

1000 m

3500 m 100 m

20 m

Node 1

Node 3

Node 2

Delay 2 Delay 4 Delay 6 Delay 8

Delay 1 Delay 3

Delay 5 Delay 7

750 m 1000 m

3200 m 100 m

Node 3 Node 2

Delay 9

20 m 20 m

Channel A

Channel B

Figure 14 - Maximum Propagation Delay Through a Redundant Network

Calculate and Total Delays for Channel A

Delay 1 500 m coax cable x 4.17 ns/m = 2.085 μs

Delay 2 Coax repeater; 901 ns + 100 ns = 1.001 μs

Delay 3 1000 m coax cable x 4.17 ns/m = 4.17 μs

Delay 4 Fiber repeater; 901 ns + 153 ns = 1.054 μs

Delay 5 3500 m fiber cable x 5.01 ns/m = 17.535 μs

Delay 6 Fiber modules; 153 + 901 ns + 94 ns = 1.148 μs

Delay 7 100 m fiber cable x 5.01 ns/m = 0.501 μs

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 41

Chapter 2 Topology and Signal Considerations

Delay 8 Fiber modules; 94 ns + 901 ns = 0.995 μs

Delay 9 20 m coax cable x 4.17 ns/m = 0.083 μs

Total delay for Channel A = 28.57 μs

Calculate and Total the Delays for Channel B

Delay 1 750 m coax cable x 4.17 ns/m = 3.127 μs

Delay 2 Coax repeater; 901 ns + 100 ns = 1.001 μs

Delay 3 1000 m coax cable x 4.17 ns/m = 4.17 μs

Delay 4 Fiber repeater; 901 ns + 153 ns = 1.054 μs

Delay 5 3200 m fiber cable x 5.01 ns/m = 16.032 μs

Delay 6 Fiber modules; 153 + 901 ns + 94 ns = 1.148 μs

Delay 7 100 m fiber cable x 5.01 ns/m = 0.501 μs

Delay 8 Fiber modules; 94 ns + 901 ns = 0.995 μs

Delay 9 20 m coax cable x 4.17 ns/m = 0.083 μs

Total delay for Channel B = 28.11 μs

Skew between channels = (Delay through A) – (delay through B) = 28.57 μs – 28.11 μs = 0.46 μs

This is a valid network because the calculated skew of 0.46 μs is less than the maximum allowable skew of 1.6 μs.

42 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Chapter

Guidelines for Fiber-optic Installation

Topic Page

General Rules and Safety 43

Warnings 43

Types of Fiber Media Installations 45

General Rules and Safety

Warnings

This section outlines specific rules and guidelines to follow when you install fiber-optic cable systems.

ATTENTION: Follow these safety guidelines: Safety glasses are required to protect your eyes when you handle chemicals

and cut fiber. Pieces of glass fiber are very sharp and can easily damage the cornea of your eye.

Cleaved glass fibers are very sharp and can pierce the skin easily. Do not let cut pieces of fiber stick to your clothing or drop in the work area where they can cause injury later. Use tweezers to pick up cut or broken pieces of the glass fibers and place them on a loop of tape kept for that purpose alone. Keep your work area clean.

Laser light can damage your eyes. Laser light is invisible. Looking at it directly does not cause pain. The iris of the eye will not close involuntarily as when you view a bright light. Consequently, serious damage to the retina of the eye is possible. Should accidental eye exposure to laser light be suspected, get immediate medical attention.

Never look into a potentially active fiber with a microscope. Doing so can cause serious eye damage.

Hire Fiber-optic Specialists for Installation and Certification

You may plan and install your fiber network or contract a fiber network engineer. It’s not necessary to have your fiber specialist connect your local equipment. Someone with media installation experience can connect local equipment by using pre-terminated interconnect cables that are purchased in their required lengths. Rockwell Automation offers the short-distance (<300 m) fiber cable pre-terminated as a kit for use with the 1786-RPFS module.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 43

Chapter 3 Guidelines for Fiber-optic Installation

Single- and multi-mode pre-terminated fiber cables for medium, long, and extra-long distances also can be purchased that are made to order or off the shelf from your supplier. However, keep in mind that a fiber media installation must be certified and terminating longer distances in the field can be challenging. Trained specialists can select the correct type of fiber cable for your environmental and intrinsically safe area needs.

We recommend a trained specialist for installation of single- and multi-mode cables for the 1786-RPFM, (medium), 1786-RPFRL (long-distance), and 1786-RPFRXL (extra long-distance) fiber modules.

The specialist you choose should install your cable and terminate it following the supplier’s installation instructions. The installation should include verification testing that provides segment length and loss at the appropriate optical wavelength. Verification should also provide pass/fail based on the limits defined in the fiber module users documentation or this manual.

Guidelines for Handling Fiber-optic Cable

These guidelines are designed to protect the safety of personnel who handle fiber-optic cable. The guidelines in Ta b l e 7

help establish an environment that

allows for the best performance from your fiber-optic system.

ATTENTION: Do not look directly into the fiber ports. Light levels may cause damage to your eyesight. Do not view an active cable end through a fiber microscope.

Table 7 - Guidelines for Handling Fiber-optic Cable

Guideline Description

Minimum bend radius • Observe the minimum fiber cable bend radius specified. Skin contact • Do not touch the ends of the fiber-optic strands. The fiber can

Installation training • Train personnel on usage of the installation tools to place and

Installation regulations • Observe all local regulations for installation, including personal

break easily and pierce your skin.

terminate fiber cable. This would include training on hand-held tools, tension meters, optical power meters, cleaners, and adhesives.

safety equipment and the guidelines for its use.

44 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Guidelines for Fiber-optic Installation Chapter 3

Table 7 - Guidelines for Handling Fiber-optic Cable

Guideline Description

Proper disposal • Always dispose of fiber waste in an approved container. Disposing

Specifications • Review cable specifications for distances and required connectors.

Pulling tensions • Observe the maximum pulling tensions. Do not pull directly on fiber

ATTENTION: Do not leave any fiber pieces on your work surface. The glass is very small and can penetrate your skin easily.

of fiber waste prevents the contamination of clothes, fingers, or eyes of glass fragments. Do not leave pieces of fiber cable on your work surfaces.

• Review all cable parameters and specifications before installation.

Make sure that you have the proper amount of connectors and installation equipment. Never attempt to use non-compatible connectors and installation tools.

or force cable into a bend radius smaller than 20 times the cable diameter when under load and 10 times the cable diameter at no load. This will crack the glass and result in optical loss.

• Use a running line tension meter to determine the pulling tension

applied during cable placement.

• Never allow tight loops, knots, kinks, or tight bends in the cable.

• Entrance in and out of metal pull boxes must be smooth as not to

damage the cable sheath

Types of Fiber Media Installations

You can use fiber media in many different application types. When you plan the application of fiber media, keep in mind the following installation types.

Pulled Application Guidelines

Pull fiber-optic cable prior to connector installation since it becomes more difficult to protect fiber from stress after connectors have been installed. Connectors may be pre-installed on one end, leaving the other end for pulling. Take precautions to protect ends from damage if the cable is pre-terminated. Refer to the manufacturer’s specifications for the fiber cable for additional information.

You must identify the strength member and the optical fiber location within the cable. Afterwards, a decision should be made to choose a cable pull method—pull or indirect attachment to ensure effective pulling without fiber damage. Never pull the cable by the fiber strand.

Direct Attachment

The cable strength member is attached directly to a pulling eye. Since epoxy glass central strength members are too rigid to tie, they may be secured to the eye by using tight clamping plates or screws.

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Chapter 3 Guidelines for Fiber-optic Installation

Indirect Attachment

Indirect attachment uses a pulling grip attached to the cable’s outer jacket to distribute the pulling force over the outer portion of the cable. The pulling grip produces the least amount of stress in cables where the strength member lies directly beneath the jacket.

Conduit and Duct Installation

Installation procedures for conduit and duct installation of fiber-optic cables are very similar to those of electrical wires. Avoid yanking, flipping, or wrapping cables causing unnecessary tightening. Fiber cable, electrical wires, or small fiber-optic cables should never be subjected to foot traffic or potentially crushing forces.

Cables should be lubricated prior to pulling to minimize the pulling forces on the cables. Lubricants such as waxes, greases, clay slurries, and water-based gels are compatible with most fiber-optic jacket materials. Check with the fiber manufacture of your cable for the approved lubricants to be used on your cable.

Use this procedure for conduit or duct installation.

1. Attach the towline to the cable by using direct or indirect attachment as described in the previous section.

2. Establish two-way communication between the cable payoff station, intermediate hand assist stations, and the pulling station.

3. Use the following items for duct or cable tray replacements:

• Adjustable lip clutch winch or equivalent

• Tension monitoring system with continuous readout

• Tow line that assures minimum friction

• Dedicated inner duct, mainly for pulls in underground conduit

• Cable end caps for use in flooded or unknown conduits and sealing

cable ends after placement

4. Position the cable reel and payoff frame for pulling. a. Mount the cable reel into the payoff apparatus so that the cable pays out

from the top of the reel.

b. Attach the pulling grip to the cable and position the reel with its flanges

perpendicular to the floor or support foundation.

c. Secure the payoff frame so it cannot move during pulling.

46 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Guidelines for Fiber-optic Installation Chapter 3

IMPORTANT

5. Maintain enough slack on the cable as the pull starts to prevent the cable from contacting any equipment in the area.

Do not allow slack loops to form on the reel. Slack loops could cause a crossover and damage the cable. Always pull at slow speeds to limit the possibility of crossovers.

Plan your pull to avoid a pull equaling or exceeding the total bends to 360° per pull. If it is not possible to avoid a pull of 360°, install an intermediate junction box within the 360° pull. Plan on manually handling the cable along the pull route to help limit the bends.

6. Position the winch at the pull station to avoid a steep angle either entering the duct or exiting the cable tray.

Do not exceed the maximum pulling tension for your fiber-optic cable.

7. Leave enough extra cable to route to the equipment rack, put connectors on, and allow for future repairs when your pull is complete.

8. Cut off the pulling grip and the first 1 m (3 ft) of cable behind it.

9. Terminate the cable.

10. Measure and record the optical cable attenuation and length by using

either an OTDR (optical time domain reflectometer) or an optical test.

11. Seal the ends of the cable with endcaps until they are terminated.

In some applications you may have to start your pull in the middle of a duct or conduit and pull in both directions. In this scenario, pull in the first direction by using the reel and payoff frame. In the other direction, lay out the cable in a figure-8 pattern on the floor. When the second pull begins, hand feed the cable into the duct system.

Be certain to clear the floor of dust, debris, and dirt before placing the cable on the floor.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 47

Chapter 3 Guidelines for Fiber-optic Installation

IMPORTANT

Aerial Installation

Most round, tight buffer, and loose-tube optical cables are compatible with helical lashing, clamping, and tied mounting. These cables can be used in aerial installations by using methods similar to those for electrical cables.

The following procedure describes the stationary method for aerial cable installation.

Aerial cable must be properly supported using ‘J’ hooks or loops of wire of sufficient diameter not to damage the fibers due to loading.

1. Use the following tools for aerial placement:

• Adjustable lip clutch winch or equivalent

• Tension monitoring system with continuous readout

• Tow line that assures minimum friction over cable blocks

• A payoff apparatus equipped with a breaking system. The breaking

system can be used to place light tension on the cable during placement.

2. Mount the cable reel into the payoff apparatus so that it pays out from

the top.

Do not drag fiber-optic cable across or around any obstacles that may cause outer jacket abrasion.

3. Determine the direction to pull your cable.

• Pull the cable up-grade whenever possible

• Place the payoff apparatus on an even surface and in-line with the

support strand whenever possible

4. Place cable blocks along the support strand at a distance of no greater than 15 m (50 ft) apart. The first cable block should be placed as close to the initial pole as possible.

5. Place additional cable blocks:

• One on each side of a corner

• Where distinct vertical clearances are required

6. Guide the cable to a position parallel with the strand as it approaches the payoff by securing the cable guide to a strand by using a guy clamp on the strands behind the first roller.

• Place the cable 0.6 m (2 ft) past the pole if the cable should start at a

dead end pole

• Place the first cable block within 0.3 m (1 ft) if the pull starts midstrand

between poles

Use manila rope (1/4-in., min), kevlar rope, capstan winch rope, or coated line winch rope as a cable towline.

48 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Guidelines for Fiber-optic Installation Chapter 3

IMPORTANT

7. Place a one-sheave cable block or snatch block within 0.3 m (1 ft) of the pole at the end of the pull. Make sure the winch is positioned to avoid steep angles exiting the block.

8. Thread the towline through the all of the cable blocks and the cable guide to the end of the cable for aerial placement.

9. Attach the towline to the cable by using direct or indirect attachment as your application dictates.

10. Establish communications between the cable payoff station, intermediate hand assist stations, and the pulling station.

11. Pull the cable slowly by using the towline and winch.

Do not exceed the maximum pulling tension as specified by the manufacturer of your cable.

12. Reverse the payoff reel by hand to rework any excessive sag between guide blocks after the pull is completed and the pulling end is anchored. Use the payoff break to maintain the proper tension.

13. Measure and record the optical cable attenuation and length by using either an OTDR (optical time domain reflectometer)

or an optical test.

14. Tighten the strand suspension clamps at the poles where the cable is to be lashed.

15. Lashing should begin immediately after the cable has been placed.

16. Pull the lasher toward the cable reel.

Always take up the slack of the unlashed spans by reversing the payoff reel slowly by hand.

17. Remove the cable blocks as the lasher progresses towards the payoff reel.

18. Secure the strand wire to keep it from loosening on the previously lashed

span as the lasher is transferred from strand to strand.

19. Proceed with the lasher until each lash is complete.

20. Leave enough extra cable to route to the equipment rack, put connectors

on, and allow for future repairs when your pull is complete.

21. Seal the ends of the cable with endcaps until they are terminated.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 49

Chapter 3 Guidelines for Fiber-optic Installation

IMPORTANT

Direct Burial Installation

Some applications call for a direct burial installation. Direct burial installation requires some special considerations that aren’t necessary for other pulled applications. These guidelines are designed to prevent hazards such as freezing water, crushing forces, ground disruption from construction, and rodents.

Use the following guidelines to help you plan your direct burial installation.

• Use cable specifically designed for direct burial.

• Use heavy duty armor cables buried directly into the ground.

• Bury the cable between 1…1.2 m (36…48 in.) deep.

• Use gel filling, metal sheathing, and armoring when possible.

• Use loose-tube cable constructions where uneven pulling forces are

a problem.

Open Trench Installation

Use these steps as a guide for installing fiber-optic cable by using an open trench method.

1. Maintain minimum tension on the cable as it rolls over the guide rollers and through the guide shoot.

Do not pull the cable in excess of its maximum allowable installation tension as specified in the cable manufacturer’s specifications.

2. Consider methods of placement like boring or creating a conduit when your installation intersects with objects like streets, sidewalks, or landscaping.

3. Maintain at least a 1 m (39 in.) separation when your fiber-optic cable is placed in proximity to an existing power cable.

4. Use some form of mechanical protection (steel pipe, cement conduit, and so forth) when adequate earth cover cannot be maintained in your application.

50 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Guidelines for Fiber-optic Installation Chapter 3

IMPORTANT

5. Use the following procedure if you must start cable placement in the middle of a selected trenching route.

a. Pull in the first direction until the end point is reached. b. Remove the cable for the opposite direction from the reel by hand and

carefully coil it on the ground in a figure-8 pattern.

Be certain to place the cable in a manner that will prevent the cable from binding against foliage, rocks, or other impediments.

c. Hand guide the cable in the second direction as the pull begins.

6. Begin cable placement as soon as possible after trenching.

You can avoid possible collapse and fill of your trench by filling it as soon as possible. Depending on your application, you may want to use a trencher with a mobile cable trailer and payoff.

7. Be certain that your cable trailer has properly sized rollers and an adjustable breaking system.

Do not allow fiber-optic cable to be pinched, braided, or bent back during payoff from the cable trailer. Do not exceed the cable’s minimum bend radius and tension. You may even want to guide your cable into the trench by hand.

8. Backfill over the cable as soon as possible after cable placement.

Consult your local ordinances for guidance on backfilling and trenching procedures.

9. Avoid backfilling with materials like frozen earth, rocks and boulders, construction debris, and so forth.

These objects could create point discontinuity along the buried cable and harm the cable’s performance.

10. Machine tap any areas where trenching could be threatened by erosion or washout.

11. Measure and record the optical cable attenuation and length by using either an OTDR (optical time domain reflectometer) or an optical test.

12. Seal the ends of the cable with endcaps until they are terminated.

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Chapter 3 Guidelines for Fiber-optic Installation

Vertical Installation

The requirements of your application may require a vertical installation. You can install fiber-optic cable vertically in trays, shafts, or towers. Dielectric cables are recommended for applications requiring high vertical installations, radio towers for example.

Use the following guidelines when planning a vertical cable installation.

1. Clamp cable to give extra support in preventing ice loading and wind slapping.

Your specific environment will determine where you should clamp your cable. Clamping intervals can be as short as 1 m (3 ft) and as long as 15…30 m (50…100 ft) in interior locations.

Cables in vertical cable shafts are generally clamped directly to the walls of the shaft.

Cables installed in elevator shafts are usually supported by suspension strands and suspended from the top of the shaft. The suspension strand is attached to the wall at frequent intervals and at the bottom of the shaft. Consult your local codes and practices for installation in an elevator shaft.

2. Avoid downward migration of cable in loose-tube constructions by looping the cable approximately 0.3 m (1 ft) in diameter at the top, bottom, and every 150 m (500 ft).

In loose-tube constructions cable may migrate downward creating crowding at the bottom. The crowding may cause an increase in attenuation, especially in below freezing temperatures.

3. Plan cable runs that keep bends to a minimum.

4. Drill all holes for the entire run larger enough to accommodate steel sleeves

when passing cables through walls and floors.

The inside diameter of steel sleeves should be 4 times the diameter of the cable. The minimum diameter of a steel sleeve is 5 cm (2 in.).

Steel sleeves are required to run cable through a firewall. Consult your local codes and practices for installations through firewalls.

5. Measure and record the optical cable attenuation and length by using either an OTDR (optical time domain reflectometer) or an optical test.

6. Seal the ends of the cable with endcaps until they are terminated.

52 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Chapter

30690

Terminate Your Fiber-optic Cable

Topic Page

What Is Termination? 53 Terminate Your Cable 54

What Is Termination?

Termination is the process of attaching a connector to the ends of your fiber cable. Use protective caps on the ends of unused connectors.

Follow these additional recommendations to terminate your fiber cable:

• Decide on the type of cable dressing based on the fiber cable construction (for example, loose tube, zipcord, simplex, and so forth)

See page 31

• Decide if a patch panel is to be used – A loose tube cable should be terminated into a patch panel – Jumpers should be used to connect the segment from the patch panel to

the fiber repeater; determine the jumper lengths for the patch panel

• Route fiber cable in the cabinet appropriately

• Provide sufficient cable length for maintenance and determination if it

becomes necessary to re-terminate the fiber ends

• ST-type terminations must be plastic or ceramic; no metal

Figure 15 - Patch Panel Example

for more information.

Figure 15 shows a patch panel with incoming multi-fiber backbone cable and

connectors for interconnect cables.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 53

Chapter 4 Terminate Your Fiber-optic Cable

Terminate Your Cable

Most connector manufactures offer connector termination systems that are specific to the connector. We recommend that the termination kit be purchased from the same manufacture.

There are two types of connector systems in the market:

• One common type is fast termination where the cable end is prepared and inserted into the back end of the connector. The system then locks the cable and fiber in place. This type uses an index matching gel so no fiber polishing is needed.

• Other connector termination systems require polishing and are more difficult to use.

You must decide which connector system is appropriate for your needs.

Ta b l e 8

details the connector types that fiber repeaters use in the

ControlNet network.

Table 8 - Termination Kits

Fiber Module Kit Types

1786-RPFS V-Pin pre-terminated and commercially available field termination kits

1786-RPFM 1786-RPFRL

1786-RPFRXL ST, SM, and MM connector pre-terminated or commercially available

are available. ST, and MM connector pre-terminated or commercially available field

terminations kits are available.

field termination kits are available.

Follow these general instructions when terminating fiber cable.

1. Organize your termination kit materials.

2. Reference your plan to be certain that you have enough supplies to make

the fiber connections and to terminate all used fiber cable ends.

3. Follow the assembly and safety procedures for your termination kit.

4. Place a dust cap (supplied in fiber cable kits) on the end of the connector.

ATTENTION: Do not let the ends of a fiber-optic strand come into contact with dust, dirt, or other contaminants. Clean contaminated ends with a soft, clean, lintless cloth and alcohol.

Always attach protective caps onto fiber cable connectors and fiber ports when they are disconnected.

54 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Chapter

Verify Your Network

Topic Page

Set Network Parameters 55

Measure Power Loss 55

OTDR Measurement 57

Set Network Parameters

Measure Power Loss

You can use RSNetWorx for ControlNet software to determine if network parameters are set up correctly. Based on the system parameters you entered, such as, NUT, SMAX, UMAX, and worst-case network delay, RSNetWorx software calculates scheduled messaging for your network.

If your network is not valid, you must adjust your parameters.

For more information, see Getting Results with RSNetWorx for ControlNet, publication CNET-GR001

After you install short-, medium- or long-distance fiber cable, check your sections by using an optical power meter to verify that your attenuation is less than or equal to the maximum allowed by the fiber type. The light source you are using must match the wavelength of the fiber module in use.

See Tab le 9 o n pa ge 5 6

The power loss measurement should match the tables in Chapter 2. If you do not follow the cable insertion loss recommendations in Table 5 on page 33 assume that you will have high-loss cable and high-loss connections.

for the wavelengths of each module.

, you can

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 55

Chapter 5 Verify Your Network

Power source must match the cable segment you are testing.

Power Meter

Do not test the cable with the wrong power source because you will get inaccurate readings. The power budgets are at the source wavelengths.

Table 9 - Fiber Operation Wavelengths

Module Wavelength

1786-RPFS 650 nm 1786-RPFM 1300 nm 1786-RPFRL/B 1786-RPFRXL/B

Verify each segment length by using an optical time domain reflectometer (OTDR) field tester or by using the markings on the cable jacket.

See page 57

for more information.

Optical power meters transmit a light source at one end of your cable with an optical power meter at the other end of the cable. You can read the attenuation or power from the power meter to confirm the attenuation of your section.

See Tab le 5 o n pa ge 3 3

for module distance ratings.

Incorrect Loss Measurement Example

If you are testing a single-mode or multi-mode cable with a 640 nm light source, you will get an incorrect loss measurement. You must test the fiber at 1300 nm to match the cable rating.

Always record and maintain records for attenuation levels for each cable section strand. The attenuation records are valuable tools for troubleshooting and

56 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

maintaining your network.

Verify Your Network Chapter 5

IMPORTANT

Considerable power loss in your cable could be a result of the following conditions:

• Poor splices

• Improper bend radius

• Bending losses

• Broken fibers

• Poor connections

• Contaminated or damaged connectors

• High fiber bend radius

• Poorly polished connector

OTDR Measurement

In addition to power loss measurement, you should examine your total fiber network by using an optical time domain reflectometer (OTDR). The OTDR emits light into a strand of fiber optic cable and displays the reflected light.

Disconnect the fiber modules from the fiber cables before performing an OTDR test.

OTDR tests provide the following measurements that will help you troubleshoot and maintain your network.

• Total distance along the cable to a fiber break

• Distance to an event (splice, bend, connector) that attenuates the light

• Distance between two attenuating events

• Light attenuation between two points of the cable

• Total reflected light or light reflected from a single event

Keep records of the traces for each cable strand on either hard copy or computer backup.

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Chapter 5 Verify Your Network

Notes:

58 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Appendix

IMPORTANT

Install Your Fiber Repeater Modules and Repeater Adapters

Topic Page

Installation Guidelines 59 Mount the Fiber Module 60 Connect a 1786-RPFS Module 65 Connect Fiber Repeater Modules 66 Wire a Repeater Adapter Module 68 Troubleshoot the Module 69 Specifications for Fiber-optic Cable 70

Installation Guidelines

Use these guidelines when you install your fiber repeater modules and repeater adapters.

Because two paths to the same nodes are not allowed, do not make a fiber or copper connection between modules that are connected to the same repeater adapter.

• Observe the environmental specifications for the fiber units as outlined in each installation instruction.

• Avoid electrostatic and electromagnetic fields at installation sites.

• Avoid corrosive and inflammable gases, dust, conductive particles, oil mist,

and organic solutions when choosing an installation site.

• Prevent equipment exposure to water or direct sunlight.

• Mount the units in a NEMA-rated enclosure based on the environmental

protection for where the units are being installed.

Fiber repeater modules are IP20 components. IP means Ingress Protection, a rating based on the IEC 60529 standard to determine the strength of an enclosure for electrical equipment.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 59

Appendix A Install Your Fiber Repeater Modules and Repeater Adapters

TIP

42542

• Allow a minimum of 5 cm from surrounding equipment for proper ventilation.

• To maintain proper ventilation, do not mount the repeater modules upside down.

• Use zinc-plated yellow-chromate-steel DIN rails to prevent corrosion.

Horizontal mounting is preferred. Vertical mounting is allowed. We recommend that the 1786-RPA/B module be mounted at the top if vertical mounting is chosen.

ATTENTION: Never install a 1786-RPCD repeater module to the right of a 1786-RPFRL/B or 1786-RPFRXL/B fiber repeater module on the same DIN rail. The1786-RPCD repeater module will not operate properly. Install the 1786-RPCD repeater module to the left of a 1786-RPFRL/B or 1786-RPFRXL/B fiber repeater module.

Mount the Fiber Module

The following steps are generic for mounting a module. Refer to the documentation with the repeater adapters and modules for specific installation information.

ATTENTION: This product is grounded through the DIN rail to chassis ground. Use a zinc-plated yellow-chromate-steel DIN rail to assure proper grounding. The use of other DIN rail materials (for example, aluminum or plastic) that can corrode, oxidize, or are poor conductors, can result in improper or intermittent grounding. Secure DIN rail to mounting surface approximately every 200 mm (7.8 in.) and use end-anchors appropriately.

1. Position the module at a 30° angle.

2. Hook the lip on the rear of the module onto the top of the DIN rail, and

rotate the module onto the rail.

3. Press the module onto the DIN rail until flush.

60 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Install Your Fiber Repeater Modules and Repeater Adapters Appendix A

TIP

42543

41900

Protective Cap

DIN Rail

Protective Backplane Cap

Both sides of the module contain a backplane connector.

The locking tab should snap into position and lock the module to the DIN rail.

Use a screwdriver to move the locking tab downward, if the module is not secured.

WARNING: Removal and insertion under power (RIUP) is not supported. These modules must be powered down while connecting and disconnecting them from any interconnected modules.

If you insert or remove the module while backplane power is on, an electrical arc can occur. This could cause an explosion in hazardous location installations.

Be sure that power is removed or the area is nonhazardous before proceeding.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 61

4. If necessary, remove the protective caps from the transmit and receive

fiber channels.

If Then

You will use a channel Remove the protective cap from the channel. You will not use a channel Keep the protective cap on to protect the You place the module in storage

channel from dust.

Appendix A Install Your Fiber Repeater Modules and Repeater Adapters

IMPORTANT

TIP

30077

5. If applicable, slide the module to the left to mate with the repeater adapter or another repeater module.

ATTENTION: Do not discard the end cap. Use this end cap to cover the exposed interconnections on the last module on the DIN rail. Failure to do so could result in equipment damage.

Make certain that you secure the repeater adapter and repeater modules with DIN-rail anchors. If you do not, loss of communication or module damage may result.

You can attach a maximum of four modules to the repeater adapter or attach the number of modules whose total power consumption does not exceed 1.6 A @ 5V DC, whichever occurs first.

Install the Ferrites

A ferrite is connected to the relay contact connector on the 1786-RPFRL/B and 1786-RPFRXL/B modules. A relay contact connector helps identify a faulted module in your system.

If you are not planning to use the relay contact connector on the module for system status, you do not need to install the ferrites.

Do these steps to attach the ferrite to the power supply of the 1786-RPA/B repeater adapter module.

1. Obtain 0.25…2.5 mm your application.

(22…14 AWG) wire in a length sufficient for

You may want to choose a smaller wire gauge (for example,

0.25…0.823 mm to handle amperage requirements of the power supply to aid in installation of the ferrite.

(22…18 AWG) ) with sufficient size and rating

62 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Install Your Fiber Repeater Modules and Repeater Adapters Appendix A

IMPORTANT

Loop the wire around the ferrite.

Twist the wires.

31530

Connect the power supply wires.

31528

2. Use the key supplied with the ferrite to open it.

3. Twist the wires, but be careful not to damage them.

4. Form a loop with both wires (+ and -) approximately 100 mm (4 in.) away

from the power supply connector of the 1786-RPA/B module.

5. Loop the wires through the ferrite.

6. Close the ferrite.

Be careful not to damage the wires.

7. Strip approximately 6 mm (0.24 in.) of wire from the end that will connect to the power supply connector on the 1786-RPA/B module.

8. Remove the power supply connector from the 1786-RPA/B module.

9. Install the stripped ends of the wires in the power supply connector on the

1786-RPA/B module.

Do not use more than one ferrite per 1786-RPA/B module.

10. Reinsert the power supply connector into the 1786-RPA/B module.

Install the Ferrite at the Relay Contact Connector

1. Use the key to open the remaining ferrite.

2. Form a loop with both wires (+ and -) approximately 100 mm (4.0 in.)

away from the relay contact connector of the 1786-RPFRL/B or 1786-RPFRXL/B module.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 63

Appendix A Install Your Fiber Repeater Modules and Repeater Adapters

Connect the ferrite here.

31531-M

3. Loop the wires through the ferrite.

4. Close the ferrite.

Be careful not to damage the wires.

5. Strip approximately 6 mm (0.24 in.) of wire from the end that will connect to the relay contact connector on the 1786-RPFRL/B or 1786-RPFRXL/B module.

6. Remove the relay contact connector from the 1786-RPFRL/B or 1786-RPFRXL/B module.

7. Install the stripped ends of the wires in the relay contact connector on the fiber repeater module as shown below.

8. Reinsert the relay contact connector into the 1786-RPFRL/B or 1786-RPFRXL/B module.

9. Connect the fiber cable as described on page 66

10. If you plan not to use a channel, attach a small section of fiber cable (or a Simplex fiber loop) between the Receive port (RX) and the Transmit port (TX) of any unused fiber port to create a jumper.

Although not required for module operation, the jumper turns the status indicators green and prevents the relay contact connector from opening and indicating a failure.

64 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Install Your Fiber Repeater Modules and Repeater Adapters Appendix A

IMPORTANT

30079

Channel 1, A and B

Channel 2, A and B

Connect a 1786-RPFS Module

The 1786-RPFS module requires a pre-terminated zipcord wiring kit. The kits are offered in a variety of lengths. Consult with your local distributor for attenuation specifications before you purchase your fiber media components.

The zipcord uses a duplex cable that contains two separate fibers, one for transmit and one for receive. If you are wiring only one channel, you can use either channel 1 or channel 2.

1. Hold down the latch and insert the channel 1 zipcord connector into the A and B connectors until the pins and latch lock into place.

Make certain you insert the blue pin, receive, of the zipcord connector in A and the black pin, transmit, into B.

2. Hold down the latch and insert the other end of the duplex cable into another module by using either channel 1 or channel 2 of the other module.

The duplex cable is manufactured with the fiber reversed on opposite ends. This automatically connects channel A of one unit to channel B of the other. Do not connect more than one duplex fiber or two simplex fibers between the same modular repeaters, even if they are from different modules on the same repeater.

See page 66

for using a tracer on a duplex cable.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 65

Appendix A Install Your Fiber Repeater Modules and Repeater Adapters

TIP

42550

Connect Fiber Repeater Modules

This section describes how to connect cables for fiber repeater modules (other than the 1786-RPFS; see page 65

). A tracer on a duplex cable helps to identify and follow the cable throughout your system. A tracer is one of the two wires on the duplex cable that is one of the following:

• Printed with the cable legend

• Ribbed

Connect the cable between the fiber modules by making a simple crisscross connection. To do this, you will connect the cables between modules from the receive (RX) end of one channel to the transmit (TX) end of the other module, as shown in the following diagram.

Channels 1 and 2 on the module are identical. Channel 1 of a module can be connected to either channel of another module.

Do these steps to connect the cable.

1. Use the tracers on the cable to identify which cable is connected to the receive (RX) port and which one to the transmit port (TX).

2. Connect the receive port (RX) and transmit port (TX) at the starting module.

3. Do the following to attach the cable connector to the module connector.

a. Align the key of the cable connector with the slot in the module

connector, and insert the connector into the RX port.

b. Push and twist the locking cap until the bayonet lug is locked into place.

66 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Install Your Fiber Repeater Modules and Repeater Adapters Appendix A

IMPORTANT

4. At the second module, connect the cables in reverse.

For example, tracer to TX port on module 1, non-tracer to RX port on module 1: tracer to RX port on module 2, non-tracer to TX port on module 2.

ATTENTION: Do not look directly into the optical port to avoid damage to your eyes.

Terminate the Cable

Termination is the process of attaching connectors to the ends of fiber cable. Follow these general instructions when terminating fiber cable.

ATTENTION: Safety glasses are required to protect your eyes when you handle chemicals and cut fiber. Pieces of glass fiber are very sharp and can easily damage the cornea of your eye.

Be certain to follow the instructions that are provided by your fiber termination kit manufacturer.

1. Organize your termination kit materials.

2. Reference your plan to be certain that you have enough supplies to make

the fiber connections and to terminate all used fiber cable ends.

3. Make a schedule for performing the connections.

4. Follow the assembly and safety procedures for your termination kit.

5. Place a dust cap (supplied in fiber cable kits) on the end of the connector.

ATTENTION: If this equipment is used in a manner not specified by the manufacturer, the protection provided by the equipment may be impaired.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 67

Appendix A Install Your Fiber Repeater Modules and Repeater Adapters

TIP

Vin + and Vin Terminals

31456-M

Wire a Repeater Adapter Module

This section describes how to wire a repeater adapter module.

WARNING: An electrical arc can occur under these circumstances:

- When you connect or disconnect the removable terminal block (RTB) with field side power applied

- If you connect or disconnect the communication cable with power applied to this module or any device on the network

This could cause an explosion in hazardous location installations. Be sure that power is removed or the area is nonhazardous before proceeding.

Make sure you have obtained the following items before you begin to wire the module:

• Two lengths of 0.21…3.3 mm

(24…12 AWG) wire

• Wire stripping tool

• Small, flathead screwdriver

Follow these steps to wire the module.

1. Strip about 7 mm (0.28 in.) of insulation from the end of each wire.

2. Attach the V

+ wire to one of the Vin + terminals on the RTB.

Tighten the screws to 0.6…0.8 N•m (5…7 lb•in).

3. Attach the V

- wire to one of the Vin - terminals on the RTB.

Tighten the screws to 0.6…0.8 N•m (5…7 lb•in).

The unused Vin + and Vin - terminals can be used to supply power to other devices.

4. Install the removable terminal block (RTB) onto the repeater adapter module.

Tighten the screws to 0.6…0.8 N•m (5…7 lb•in).

68 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Install Your Fiber Repeater Modules and Repeater Adapters Appendix A

31459-M

BNC Connector

5. Connect the repeater adapter module to the ControlNet network by connecting the drop line of the coax tap to the BNC connector.

6. Terminate any unused coax ports by connecting a 75 Ω terminator to the unused BNC connector.

One 75 Ω terminator is shipped with the repeater adapter module.

Troubleshoot the Module

Use the channel 1 or channel 2 status indicators to check module status and troubleshoot the module.

For status indicator descriptions, see page 73

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 69

Appendix A Install Your Fiber Repeater Modules and Repeater Adapters

Specifications for Fiber-optic Cable

The quality of the fiber cable determines the distance you can achieve. Consult your your local distributor for attenuation specifications prior to purchasing your fiber media components.

1786-RPFS Fiber-optic Cable

Item Description

Fiber type 200/ 230 micron HCS (hard- clad silica) Fiber termination type Versalink V– System Jacket PVC Pull tension, max 110 lb (490 N) Cyclic flexing >5000 Bend radius, min 25 mm Temperature, operating -20 °C (-4 °F)…80 °C (176 °F) Temperature, nonoperating -40 °C (-40 °F)…80 °C (176 °F) Fiber operating wavelength 650 nm (red) Optical power budget 4.2 dB

(1) This includes all loss associated with the fiber link, including splices, fiber attenuation, bulkhead

connectors, and the ST terminations.

(1)

1786-RPFM Fiber-optic Cable

Item Description

Fiber type 62.5/125 µm micron multi-mode OM-1 fiber Fiber termination type ST (plastic or ceramic only; do not use metal

Fiber operating wavelength 1300 nm Optical power budget 13.3 dB

(1) This includes all loss associated with the fiber link, including splices, fiber attenuation, bulkhead

connectors, and the ST terminations.

connectors)

(1)

1786-RPFRL/B Fiber-optic Cable

Item Description

Fiber type 62.5/125 µm micron multi-mode Fiber termination type ST (plastic or ceramic only; do not use metal

Fiber operating wavelength 1300 nm Optical power budget 15 dB

(1) This includes all loss associated with the fiber link, including splices, fiber attenuation, bulkhead

connectors, and the ST terminations.

connectors)

(1)

70 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Install Your Fiber Repeater Modules and Repeater Adapters Appendix A

1786-RPFRXL/B Fiber-optic Cable

Item Description

Fiber type 62.5/125 µm micron

Fiber termination type ST (plastic or ceramic only; do not use metal

Fiber operating wavelength 1300 nm Optical power budget 10.5 dB

(1) This includes all loss associated with the fiber link, including splices, fiber attenuation, bulkhead connectors,

and the ST terminations.

multi-mode

connectors)

(1)

9/125 µm micron single-mode

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 71

Appendix A Install Your Fiber Repeater Modules and Repeater Adapters

Notes:

72 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Appendix

IMPORTANT

Repeater Adapter

Repeater Modules

Status Indicators

The 1786-RPA/B repeater adapter has a pair of status indicators:

• One status indicator for the condition of the coax connection

• One status indicator for the accumulative indications of fiber channels

The status indicators on the repeater adapter module can be interpreted alone or together.

COM

24V

COM

REPEATER

ADAPTER

REPEATER

MODULES

The following three tables list different combinations of status indicators and their interpretations.

Status Indicators Page

Power-up and fault conditions Table 10 on page 74 Repeater adapter module only Table 11 on page 74 Repeater modules only Table 12 on page 75

The following are the only valid indicator combinations. Other combinations are not valid. For example, the combination of the repeater adapter module’s solid green status indicator and the repeater module’s solid red status indicator is not valid and probably indicates a defective module.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 73

Appendix B Status Indicators

Table 10 - Power-up and Fault Conditions

Indicator Status Description

Repeater adapter Alternating red/green Repeater adapter module is being

powered up or reset. Do nothing. The repeater adapter module is operating properly.

Solid red A jabber condition has occurred.

Another node or repeater on the network is transmitting constantly. Check the network and components for proper operation.

Off Repeater adapter module is not

powered up or has failed. Check the power input to the repeater adapter module for correct voltage and polarity.

Table 11 - Repeater Adapter Module Status Indicator

Indicator Status Description

Repeater adapter Solid green Error-free data is being recovered

at the coax port of the repeater adapter module. Do nothing. This is the normal operating mode.

Flashing green/off Data with errors is occasionally

being recovered at the coax port of the repeater adapter module.

This situation normally corrects itself. If the situation persists, check the following:

• All BNC connector pins are

seated properly.

• All taps are Rockwell

Automation taps.

• All terminators are 75 Ω and are

installed at both ends of all segments.

• Coax cable has not been

grounded.

Flashing red/off Either no data is being received at

the coax port of the repeater adapter module, or data with a large number of errors is being received at the coax port of the repeater adapter module.

Check the following components:

• Broken cables

• Broken taps

• Missing segment terminators

74 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Status Indicators Appendix B

Table 12 - Repeater Modules Status Indicator

Indicator Status Description

Repeater module Solid green Error-free data is being recovered

Flashing green/off Data with errors is occasionally

Flashing red/off Either no data is being received at

at all of the attached repeater modules. Do nothing. This is the normal operating mode.

being recovered at some or all of the repeater modules.

This situation normally corrects itself. If the situation persists, check the following:

• All BNC connector pins are

seated properly.

• All taps are Rockwell

Automation taps.

• All terminators are 75 Ω and are

installed at both ends of all segments.

• Coax cable has not been

grounded.

• Fiber-optic connectors are of the

correct type and are correctly attached to the fiber-optic cable.

• Fiber-optic cable is the correct

type.

any of the repeater modules, or the received data at some or all of the repeater modules has a high number of errors.

Check the following components:

• Broken cables

• Broken taps

• Missing segment terminators

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 75

Appendix B Status Indicators

Channel 1 Status Indicator

Channel 2 Status Indicator

30041

1786-RPFS and 1786-RPFM Status Indicators

Use the channel 1 or 2 status indicators to check module status.

Table 13 - Short- or Medium-distance Fiber Repeater Modules

Indicator Status Description

Either channel 1 or channel 2

Off Repeater not connected to power

supply. Green Channel is operating normally. Flashing green No activity on the channel.

76 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Status Indicators Appendix B

Channel 1 Status Indicator

Channel 2 Status Indicator

45792

1786-RPFRL/B or 1786-RPFRXL/B Status Indicators

Use the channel 1 or 2 status indicators to check module status.

Table 14 - Long- or Extra-long Fiber Repeater Modules

Indicator Status Description

Repeater module Off Fiber repeater module is not

Green The fiber repeater module is

Flashing green/off No data activity on the network.

Flashing red/off Module is powered, but not ready

Intermittent red As more data errors are detected,

connected to the power supply. Connect the repeater to the power supply.

operating properly.

If the cable is attached, do the following:

• Make sure the receive (RX)

channel is connected to the transmit (TX) channel on both modules.

• Check for broken fiber.

for operation. This state should also occur during module reset and last for approximately 5 seconds. Do nothing. The fiber repeater module is operating properly.

the frequency of the flashing red increases until a solid red is displayed. Check for proper operation.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 77

Appendix B Status Indicators

Relay Contact Connector

31531-M

Table 14 - Long- or Extra-long Fiber Repeater Modules

Indicator Status Description

Repeater module Red Excessive receive signal distortion.

Review these items:

• Be certain that you are using the

correct fiber type for your module.

• Check fiber length and

attenuation to make sure that it is within specification.

• Replace the downstream

1786-RPFRL module on the channel that has the intermittently flashing red status indicator.

• Be certain that your total

network length is not out of specification.

• Be certain that SMAX is

correctly defined in the RSNetWorx for ControlNet software.

1786-RPFRL/B or 1786-RPFRXL/B Relay Contact Connectors

The 1786-RPFRL/B and 1786-RPFRXL/B fiber repeater modules contain a single electromechanical relay for communication and system status. The relay provides an efficient way to locate a faulted module.

Table 15 - Relay Contact Connector Diagnostics

Indicator Status Description

Channel 1 or channel 2

Not solid green The relay contact is open.

No receive data is present at one or

both fiber-optic ports for more than

1300 ms (that means if either of the

channel status indicators are not

solid green, the fault relay opens.)

The repeater is not connected to

the power supply. Off The relay contact is closed.

Neither of the above conditions

is met.

78 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

The following terms and abbreviations are used throughout this manual. For definitions of terms not listed here, refer to the Allen-Bradley Industrial Automation Glossary, publication AG-7.1

APD (avalanche photo diodes) Converts light to current in fiber receivers.

attenuation (loss) Ratio of input optical power to output optical power for a length of fiber optic

cable in dB/km.

bandwidth Pulse broadening caused by multi-mode dispersion and chromatic dispersion

within the cable.

baseband Information is transmitted through fiber by modulation of the optical power.

BER (bit error rate) Primary method of describing the data error rate. An acceptable error rate is

-9

1 × 10

bend radius Maximum amount the cable can be bent and still function up to specification.

buffer Material surrounding the fiber (core, cladding, coating) that protects the fiber

from physical damage. Tight buffers are in direct contact with the fiber. Loose-tube buffers provide a free environment for the fiber to float.

bit errors (or 1 error in 1000 Mbits transmitted).

Glossary

cladding Layer of material surrounding the core of a fiber.

coating Protective plastic material surrounding the cladding.

core Central cylinder of a fiber that is made of plastic or glass.

dB Unit of measure for loss or gain of power described as 10 × log (pout/pin).

dBM Power level referenced to 1 mw described as 10 × log (poptical/1 mw).

ferrite A passive electric component that is used to suppress high frequency noise in

electronic circuits.

graded index Fiber system where light travels in wave-like tracks to increase cable bandwidth.

insertion loss Loss in dB caused by the disruption of light when an object is inserted in the light

path (a connector, bulkhead, splice, or cable).

laser diode Converts electric energy into light energy to be coupled onto fiber media.

LED (light emitting diode) Converts electric energ y into light.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 79

Glossary

local area network Family of computer networks, industrial control networks, and office networks

used in short-distance, multi-user environments.

loss see attenuation (loss)

multi-mode Class of fibers where the light travels in multiple paths down the fiber core.

numerical aperture (NA) In a lens or fiber, the sine of half the maximum angle of acceptance α. NA = sin α

= √(n1

- n22) where n1= core refractive index and n2=cladding refractive index.

network update time (NUT) Time necessary to complete the scheduled bandwidth, unscheduled bandwidth,

and network maintenance in the network interval.

OTDR (optical time

domain reflectometer)

photo diode see pin diode

pin diode Used as a receiving device in fiber optic systems to detect the presence of light and

plastic clad silica fiber Step-index fiber made from silica core and a plastic cladding.

plastic fiber fiber consisting only of plastic with usually higher attenuation than glass.

receiver Produces logic levels in a fiber optic system by using photo diodes, resistors,

refractive index Ratio of the speed of light in a vacuum to the speed of light in the material.

responsivity Ratio of output current/voltage to the optical input power.

return loss Logarithmic ratio of power into a device to the power reflected back due to

scheduled maximum node address

(SMAX)

Tool for characterizing fiber attenuation, uniformity, splice loss, breaks, or length.

convert that light energy into electrical energy.

amplifiers, and level shift circuits.

mismatches in a system. Return Loss = 10 × log (P

in/Pback

Highest scheduled node address on the ControlNet network.

sensitivity Minimum optical power amplitude at the input of a receiver in order to achieve a

predefined BER.

single-mode Class of fibers in which light travels in a single path down the fiber core.

speed of light Phase velocity of an optical wave in a vacuum.

80 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

splice Connection in the fiber designed to increase the length of the fiber.

step index Fibers with a refractive-index profile form in a rectangle.

tap Couples a fraction of optical power from a fiber to a receiver.

Glossary

unscheduled maximum node address

(UMAX)

The highest unscheduled node address on the ControlNet network.

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 81

Glossary

Notes:

82 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Index

Numerics

1786-RPA/B module

status indicators wiring

1786-RPFM module

cable specifications status indicators 76

1786-RPFRL/B module

cable specifications description relay contact connector 78 status indicators

1786-RPFRXL/B module

cable specifications description 35 relay contact connector status indicators

1786-RPFS module

cable specifications connection description status indicators 76

attenuation

levels

medium distance 37, 38

records

BNC

cable connectors

cable

200 micron HSC connectors estimate lengths specifications

1786-RPFM module 1786-RPFRL/B module 70 1786-RPFRXL/B module 1786-RPFS module

terminate

cable type

duplex multi-fiber backbone

simplex

coax

constraints

combination

installation

conduit

installation

30 20 46

connection

1786-RPFS module fiber repeater module poor 57

considerations

topology

constraints

coax fiber 31

ControlNet network cable system

connectors node tap 15

current draw

repeater modules

delay

propagation values

duct

installation

duplex

cable type

electrical isolation 12 entry into hazardous areas estimate

cable lengths

ferrite

definition power supply relay contact connector

fiber

cable cross-section cable guidelines cable specifications connectors 12 constraints handling guidelines longer distances media media components media specialist mount module repeater module

connection

guidelines

handling cable installation

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 83

Index

immunity

to interference

installation

aerial combination conduit and duct direct attachment 45 direct burial fiber media guidelines 59 indirect attachment open trench parallel 20 planning pulled

ring 20 series

vertical

intrinsically safe area 11

longer distances

fiber media

loss

budget

measurement

between repeater modules

incorrect fiber test

maximum

propagation delay

measure

module

mount

multi-fiber backbone

redundant network

OTDR

troubleshoot

fiber module

cable type

69 60

network

parameter verification propagation delay 39 SMAX parameter terminate medium-distance cable topology

nodes

OTDR 49

measurement

parallel

installation

point-to-point

topology

power

loss measurement repeater modules

propagation

delay

redundant

network

propagation delay

topology

redundant networks relay contact connector

1786-RPFRL/B module 1786-RPFRXL/B module 78 ferrite

repeater

adapter configuration

current draw description

ring

installation topology

RSNetWorx for ControlNet

software

in parallel in series series and parallel 23

14 20

21, 55

safety

general rules

series

installation

signal delay simplex

cable type

size and weight SMAX parameter ST

connectors

star

topology

status indicators

1786-RPA/B adapter module 1786-RPFM module 1786-RPFRL/B module 1786-RPFRXL/B module 1786-RPFS module

84 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

Index

tap description 15 terminate

26, 53, 67

cable

terminating resistor

description

test

media connections and segments

topology

considerations point-to-point 16 redundant ring star 17

troubleshoot

69, 73

module

verify

network

V-pin

connector

wiring

1786-RPA/B module

worst case

signal delay

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 85

Index

Notes:

86 Rockwell Automation Publication CNET-IN001C-EN-P - October 2011

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Publication CNET-IN001C-EN-P - October 2011 88

Rockwell Automation 1786 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

ControlNet Fiber Media Planning and Installation Guide

Summary of Changes

Table of Contents

Preface

Why Choose a Fiber-optic Media System?

Analyze Your Network

Identify Fiber Media Components

Determine Network Topology

Plan the Installation of the Fiber Media Components

Choose the Fiber Media System Composition

Configure the Media in RSNetWorx for ControlNet Software

Terminate Your Fiber Cable

Test Your Fiber Media Connections and Segments

Power Your Repeaters

Verify Your Network

Develop a Plan

Redundant Media

Topology Considerations

Coax Segment Constraints

Fiber Segment Constraints

Select a Module Type Based on Distance Requirements

Estimate Cable Lengths

Determine Attenuation Levels

Determine Propagation Delay

General Rules and Safety

Warnings

Types of Fiber Media Installations

What Is Termination?

Terminate Your Cable

Set Network Parameters

Measure Power Loss

OTDR Measurement

Installation Guidelines

Mount the Fiber Module

Connect a 1786-RPFS Module

Connect Fiber Repeater Modules

Wire a Repeater Adapter Module

Troubleshoot the Module

Specifications for Fiber-optic Cable

Glossary

Index

Numerics