Rockwell Automation 1756-DH485 User Manual

ControlLogix DH-485 Communication Module

1756-DH485

User Manual

Important User Information

SHOCK HAZARD

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 available from your local Rockwell Automation sales office or online at http://literature.rockwellautomation.com

) describes some 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.

IMPORTANT

ATTENTION

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

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

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

The first line of trademarks is an example; the brand or product name changes according to publication but the rest of the line should remain the same. The second line should be used exactly as listed below in any case where it applies.

Allen-Bradley, ControlLogix, and RSLinx are trademarks of Rockwell Automation, Inc.

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

Important User Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Preface

1756-DH485 Module Overview

Overview of the DH-485 Network

Purpose of This Manual. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preface-i

Who Should Use This Manual. . . . . . . . . . . . . . . . . . . . . . . . . . Preface-i

Other Resources. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preface-i

Chapter 1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

What the Module Does . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Module Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Module Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Prevent Electrostatic Discharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Removal and Insertion Under Power . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Typical Applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Remote Messaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

Remote Upload and Download . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

Routing Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

DH-485 and CIP Messaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

Alphanumeric Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

Chapter 2

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

DH-485 Network Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

DH-485 Network Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

DH-485 Token Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

DH-485 Network Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Devices that Use the DH-485 Network . . . . . . . . . . . . . . . . . . . . . . . 2-3

1747-AIC Isolated Link Coupler for DH-485 . . . . . . . . . . . . . . . . . . 2-4

1761-NET-AIC Advanced Interface Converter Product Overview . 2-6

Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Device Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Node Address Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

Misconception about the 1761-NET-AIC Converter . . . . . . . . . . . . 2-7

1747-UIC USB to DH-485 Interface Converter . . . . . . . . . . . . . . . . 2-7

Example System Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Configure the SLC 5/03, SLC 5/04, and SLC 5/05 Controller

Channel 0 for DH-485. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

Important Planning Considerations . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

Hardware Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

Software Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

Additional Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

i Publication 1756-UM532A-EN-P - May 2006

Table of Contents ii

Use Data Highway 485 Network

Use RSLinx Software to Create a Routing Table

Chapter 3

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

What Is Data Highway 485? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Link Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Two Methods of Communication Over a DH-485 Network . . . . . . 3-2

Use DH-485 Messaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

Local DH-485 Messaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

Limitations of Local DH-485 Messaging . . . . . . . . . . . . . . . . . . . 3-5

Remote DH-485 Messaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

Configuration Information in DH-485 Messaging. . . . . . . . . . . . . . 3-11

Application Timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12

Example DH-485 Network Routing Configuration. . . . . . . . . . . . . 3-13

Use the Common Industrial Protocol (CIP) Messaging. . . . . . . . . . 3-14

Chapter 4

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Choose the Correct Software. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Use RSLinx Software to Create a Routing Table . . . . . . . . . . . . . . . . 4-2

What Is a Routing Table? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

ControlLogix Routing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

Create the Routing Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Set the Controller Slot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

Communicate from an SLC 5/03 Controller to a Logix Controller over a DH-485 Network

Chapter 5

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

Hardware Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

Use the Controller Slot to Route the Local Message . . . . . . . . . . . . . 5-3

Create a Local Message in RSLogix 500 . . . . . . . . . . . . . . . . . . . . . . . 5-4

Configure the Message. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5

Create a Logic Map for the Local Message in

RSLogix 5000 Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6

Publication 1756-UM532A-EN-P - May 2006

Communicate Between SLC Controllers over DH+ and DH485 Networks

Communicate Between a PLC-5 Controller and a Remote SLC 5/03 Controller over Multiple DH-485 Networks

Table of Contents iii

Chapter 6

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

SLC 5/04 Controller Sends a Remote Message . . . . . . . . . . . . . . . . . 6-2

Hardware Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2

Create the Routing Table in RSLinx Software . . . . . . . . . . . . . . . 6-3

Configure the SLC 5/03 Controller Channel 1 Link ID . . . . . . . 6-4

Configure the SLC 5/04 Channel 1 Link ID . . . . . . . . . . . . . . . . 6-5

Create a Message in RSLogix 500 . . . . . . . . . . . . . . . . . . . . . . . . . 6-6

Configure the Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7

SLC 5/03 Controller Sends a Remote Message . . . . . . . . . . . . . . . . . 6-8

Hardware Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8

Create the Routing Table in RSLinx Software . . . . . . . . . . . . . . . 6-9

Create a Remote Message in RSLogix 500 . . . . . . . . . . . . . . . . . 6-10

Configure the Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11

Chapter 7

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

Hardware Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

Create the Routing Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

Configure the PLC-5 DH+ Channel 1A Link ID . . . . . . . . . . . . 7-4

Create a Message in RSLogix 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4

Configure the Message. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5

Communicate from an SLC 5/05 Controller to an SLC 5/03 Controller over an EtherNet/IP Network

Communicate to a SLC 5/03 Controller on a DH-485 Network

Chapter 8

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1

Hardware Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2

Create a Message in RSLogix 500 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

Configure the Message. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4

Review the Multihop Feature in RSLogix 500 . . . . . . . . . . . . . . . . . . 8-5

Chapter 9

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1

Hardware Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-2

Create a Message in RSLogix 5000 . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3

Configure the Message. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-4

Publication 1756-UM532A-EN-P - May 2006

Table of Contents iv

Communicate from a Logix Controller to an SLC 5/03 Controller over EtherNet/IP and DH-485 Networks

Specifications

Troubleshoot the 1756-DH485 Module

Index

Chapter 10

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1

Hardware Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2

Create a Remote 1756-ENBT Message in RSLogix 5000 . . . . . . . . 10-3

Configure the Message. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4

Appendix A

Appendix B

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

Check Power Supply and Module Status . . . . . . . . . . . . . . . . . . . . . . B-1

Interpret the LED Status Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . B-2

Interpret the Alphanumeric Indicators . . . . . . . . . . . . . . . . . . . . . . . . B-3

Interpret the OK

Status Indicator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-4

Routing Errors in DH-485 Messaging . . . . . . . . . . . . . . . . . . . . . . . . B-4

Routing Errors in Local DH-485 Messaging . . . . . . . . . . . . . . . . B-4

Routing Errors in Remote DH-485 Messaging . . . . . . . . . . . . . . B-5

Rockwell Automation Support . . . . . . . . . . . . . . . . . . . . . . . . Backcover

Installation Assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . Backcover

New Product Satisfaction Return . . . . . . . . . . . . . . . . . . . Backcover

Publication 1756-UM532A-EN-P - May 2006

Preface

Purpose of This Manual

Who Should Use This Manual

Other Resources

This manual describes how to understand, configure, and troubleshoot your ControlLogix Data Highway 485 communication interface module.

This manual also provides step-by-step procedures on how to use the 1756-DH485 module to send DH-485 messages between ControlLogix, PLC, and SLC controllers in DH-485 applications.

Use this manual if you program applications that use 1756-DH485 modules. We assume you have a good understanding of the Data Highway 485 protocol. This user manual contains a brief description of the Data Highway 485 network in Chapter 2, Overview of the DH-485 Network.

Refer to the manuals listed in the table Devices that Use the DH-485 Network on page 2-3.

i Publication 1756-UM532A-EN-P - May 2006

Preface ii

Notes:

Publication 1756-UM532A-EN-P - May 2006

1756-DH485 Module Overview

Chapter

Introduction

What the Module Does

This chapter describes the 1756-DH485 module, and what you must know and do before you begin to use it.

For See

What the Module Does 1-1 Module Requirements 1-1 Module Features 1-2 Prevent Electrostatic Discharge 1-3 Removal and Insertion Under Power 1-4 Typical Applications 1-5 Remote Messaging 1-7 Routing Limitations 1-8

The 1756-DH485 module supports the following types of communication:

• Data Highway 485 (DH-485) Messaging

• Connectivity to two separate DH-485 networks in one module

• Common Industrial Protocol (CIP) Messaging

Module Requirements

1 Publication 1756-UM532A-EN-P - May 2006

The following are required for using the 1756-DH485 communication module:

• RSLinx Software, version 2.41 or later

• Node address within the range of 0-31

• AIC+ link coupler (1761-NET-AIC) communications adapter

• Compatible with SLC 5/03 controllers or later

1-2 1756-DH485 Module Overview

WARNING

Module Features

The 1756-DH-485 module offers the following features:

• Sends messages between devices on DH-485 networks and devices on other networks such as ControlNet, EtherNet/IP, or other DH-485 networks

• Bridges support to other NetLinx networks via the CLX gateway

• Configure channels and ports using RSLinx Classic software, version

2.43 or later

• Accesses other networks by using a routing table editor that lets DH-485 devices use the 1756-DH485 module and ControlLogix chassis

• Supports all benefits and attributes of a ControlLogix communication module

• Supports firmware upgrades

TIP

• Removal and insertion under power (RIUP), can be removed and inserted under power without disrupting power to other modules in the chassis

Download firmware upgrades via the backplane. Do not use DH485 network for downloads.

When 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

• 4-character display

• Default Controller Slot feature for local messaging

• Serial Port Configuration

• No limit on number of modules per chassis, up to the number of

available slots and the capabilities of the power supply

This figure shows the external features of the 1756-DH485 module.

before proceeding. Repeated electrical arcing causes excessive wear to contacts on both the module and its mating connector. Worn contacts may create electrical resistance that can affect module operation.

Publication 1756-UM532A-EN-P - May 2006

External Features of the 1756-DH485 Module

1756-DH485 Module Overview 1-3

Prevent Electrostatic

Backplane Connector

Channel and Module Status Indicators

Channel A Connector

Channel B Connector

Alphanumeric Status Indicator

The DH-485 module is sensitive to electrostatic discharge.

Door Label

43842

Discharge

ATTENTION

This equipment is sensitive to electrostatic discharge, which can cause internal damage and affect normal operation. Follow these guidelines when you handle this equipment:

• Touch a grounded object to discharge potential static.

• Wear an approved grounding wriststrap.

• Do not touch connectors or pins on component

boards.

• Do not touch circuit components inside the equipment.

• Use a static-safe workstation, if available.

• Store the equipment in appropriate static-safe

packaging when not in use,.

Publication 1756-UM532A-EN-P - May 2006

1-4 1756-DH485 Module Overview

WARNING

Removal and Insertion Under Power

You can install or remove the module while chassis power is applied if you observe the following precautions.

When 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

Publication 1756-UM532A-EN-P - May 2006

1756-DH485 Module Overview 1-5

Typical Applications

The first example is a typical gateway application connecting multiple networks together.

In this example you can:

• upload and download SLC 500 and Panelview display programs.

• seamlessly communicate between SLC controllers.

• connect multiple DH-485 networks together for inter-network

communications, for example, messages between SLC 5/03 controllers.

• provide connection to other NetLinx networks, such as EtherNet/IP, to allow a single-point access, for example: upload and download to an SLC controller, MicroLogix controller, and Panelview display.

Connection of Multiple Networks

Computer with RSlogix 500 and RSLogix 5000 Software

1756-ENBT

AIC Link Coupler

SLC 5/03 Controller

1756-DH485

AIC+ Link Couplers

AIC Link Coupler

SLC 5/03 Controller

PanelView

AIC Link Coupler

44137

Publication 1756-UM532A-EN-P - May 2006

1-6 1756-DH485 Module Overview

The second example shows how you can connect or migrate a legacy system to a new installation with RSLogix software.

• Connect multiple DH-485 networks together for inter-network communications.

• Message between SLC 5/03 controllers.

• Provide connection to other NetLinx networks.

• Access through a single point and download to an SLC controller,

MicroLogix controller, and Panelview display.

• Allow communications between legacy and ControlLogix systems for high integration of control systems (except for fixed SLC controllers).

• Phase SLC systems into ControlLogix architecture by using a migration tool.

Connect or Migrate a Legacy System to a New Installation

Computer with RSlogix 500 and RSLogix 5000 Software

ControlLogix Controller

AIC+ Link Coupler

AIC Link Coupler

AIC+

MicroLogix

ControlLogix Controller

DH485 Network

AIC Link Coupler

1756-DH485

1756-ENBT Module

AIC+ Link Coupler

AIC Link Coupler

SLC 5/03 Controller

Publication 1756-UM532A-EN-P - May 2006

SLC 5/03 Controller

PanelView Display

44136

1756-DH485 Module Overview 1-7

Remote Messaging

The configuration of remote messaging is similar to data highway remote I/O (DHRIO). It is achieved through routing table functions and module configuration. The multi-hop functionality is available in RSLogix 5 and 500 (version 6.3 or later)

Remote Upload and Download

You can bridge EtherNet/IP and ControlNet networks to a DH-485 network using the 1756-DH485 module

You can upload and download:

• all MicroLogix and SLC 500 controllers on DH-485 from NetLinx network by using RSLinx Classic software.

• PanelView Standard terminals on DH-485 from NetLinx network by using RSLinx Classic.

Logix controllers message via a NetLinx network through a ControlLogix gateway to the DH-485 network to all MicroLogix and SLC 5/03 (and above) controllers on DH-485 network. RSLinx Classic software on the DH-485 network can browse through the ControlLogix gateway to any device on a NetLinx network.

IMPORTANT

Logix controllers on a NetLinx network will not be able to initiate messages through the ControlLogix gateway to the DH-485 network to fixed SLC 500, SLC 5/01, or SLC 5/02 controllers on a DH-485 network.

Publication 1756-UM532A-EN-P - May 2006

1-8 1756-DH485 Module Overview

Routing Limitations

Data Collection and Recipe Management

The 1756-DH485 module can route a message through up to four communications networks and three chassis. This limit applies only to the routing of a message and not to the total number of networks or chassis in a system.

DH-485 and CIP Messaging

The 1756-DH485 module lets devices, such as ControlLogix, PLC, and SLC controllers exchange information. With the 1756-DH485 module, you may exchange information between the ControlLogix, PLC, or SLC controllers on different networks. Communication between SLC controllers on different networks is accomplished using remote messaging.

Communication Between SLC Controllers on Differen t Networks

RSView

Programming Terminal

EtherNet/IP Network

DH-485

SLC 5/03

PanelView

ControlLogix Chassis

MicroLogix

SLC 5/03

DH-485

ControlLogix Chassis

PanelView

44056

Publication 1756-UM532A-EN-P - May 2006

1756-DH485 Module Overview 1-9

Alphanumeric Indicators

When you apply power to the module, the alphanumeric display begins to cycle through the following sequence.

1. All LEDs flash on then off -CHA, CHB OK

2. OK displays red then changes to green.

3. INIT displays.

4. Firmware Revision flashes on scrolling display: DH-485

5. Channel A and the network used for channel A.

6. Channel A node address.

7. Channel A status.

8. Channel B and the network used for channel.

9. Channel B node address.

10. Channel B status.

This sequence runs continuously during normal module operation.

EXAMPLE

For example, if your module uses the following:

• Channel A for DH-485 with node address 14

• Channel B is not connected

and the channels are operating properly, you see the following sequence:

A DH, A#14, A OK, B DH, B#00, ONLY NODE

Refer to Appendix B, Troubleshoot the 1756-DH485 Module and publication 1756-IN587, the ControlLogix DH-485 Communications Module Installation Instructions, for more information about LEDs and status indicators.

Publication 1756-UM532A-EN-P - May 2006

1-10 1756-DH485 Module Overview

Notes:

Publication 1756-UM532A-EN-P - May 2006

Overview of the DH-485 Network

Chapter

Introduction

The information in this chapter will help you plan, install, and operate devices on a DH-485 network. This chapter also contains information that describes the DH-485 network functions, network architecture, and performance characteristics.

For See

DH-485 Network Description 2-1 DH-485 Network Protocol 2-2 DH-485 Token Rotation 2-2 DH-485 Network Initialization 2-2 Devices that Use the DH-485 Network 2-3 1747-AIC Isolated Link Coupler for DH-485 2-4 1761-NET- AIC Advanced Interface Converter Product Overview 2-6 Operating Modes 2-6 Device Compatibility 2-6 1747-UIC USB to DH-485 Interface Converter 2-7 Example System Configuration 2-8 Important Planning Considerations 2-10 Additional Resources 2-13

DH-485 Network Description

1 Publication 1756-UM532A-EN-P - May 2006

The DH-485 network passes information between devices on the plant floor. The network monitors process parameters, device parameters, device status, process status, and application programs to support data acquisition, data monitoring, program upload/download, and supervisory control.

The DH-485 network offers:

• interconnection of 32 devices.

• multi-master capability.

• token passing access control.

• the ability to add or remove nodes without disrupting the network.

(1)

• maximum network length of 1219 m (4000 ft)

(1) The network can be extended to 2,438 meters (8,000 feet) by connecting two AIC+ Advanced Interface

Converters (1761-NET-AIC). Refer to the AIC+ Advanced Interface Converter User Manual, publication number 1761-6.4.

2-2 Overview of the DH-485 Network

The protocol used to control message transfers on the DH-485 network supports two classes of devices: initiators and responders. All initiators on the network get a chance to initiate message transfers. To determine which initiator has the right to transmit, a token passing algorithm is used.

DH-485 Network Protocol

DH-485 Token Rotation

A node holding the token is able to transmit a configurable number of message packets (plus two retries) onto the network before having to pass the token on to the next node. This configuration parameter is called the Token Hold Factor and has a minimum value of one and a maximum value of four. Once a node holding the token has sent any messages that it has to send, up to its Token Hold Factor maximum allowed, it attempts to pass the token to its successor by sending a token-pass packet.

If no network activity occurs, the initiator sends the token-pass packet again. After two retries (a total of three tries) the initiator will attempt to find a new successor.

IMPORTAN

The allowable range of the node address of an initiator is 0 to 31. The allowable address range for all responders is 1 to 31. There must be at least one initiator on the network.

The maximum address that the initiator will search for before wrapping to zero is the value in the configurable parameter maximum node address. The default value for this parameter is 31 for all initiators and responders.

DH-485 Network Initialization

Publication 1756-UM532A-EN-P - May 2006

Network initialization begins when a period of inactivity exceeding the time of a link dead timeout is detected by an initiator on the network. When the time for a link dead timeout is exceeded, usually the initiator with the lowest address claims the token. When an initiator has the token it will begin to build the network. The network requires at least one initiator to initialize it.

Building a network begins when the initiator that claimed the token tries to pass the token to the successor node. If the attempt to pass the token fails, or if the initiator has no established successor (for example, when it powers up), it begins a linear search for a successor starting with the node above it in the addressing.

When the initiator finds another active initiator, it passes the token to that node, which repeats the process until the token is passed all the way around the network to the first node. At this point, the network is in a state of normal operation.

Overview of the DH-485 Network 2-3

Devices that Use the

Presently, the following SLC 500 devices support the DH-485 network:

DH-485 Network

Devices that Use the DH-485 Network

Catalog Number Description Installation

Requirement

1756-DH485 ControlLogix DH485

Communication Module

1747-Lxxx SLC 500

Programmable Controllers

1747-KE DH-485/DF1

Interface Module

1747-UIC USB to DH-485

Interface Converter

1747-AIC Isolated Link Coupler Standalone Provided connection to SLC 500 family devices to the

ControlLogix Chassis

SLC Chassis Programmable controllers. 1747-UM011

SLC Chassis Provides a non-isolated DH-485 interface for

Standalone Provides connection to personal computer’ s USB port

Function Publication

Bridge DH485 messages in ControlLogix. 1756-UM532

SLC 500 devices to host computers over RS-232 using full- or DF1 half-duplex protocol. Enables remote programming to an SLC 500 controller or the DH-485 network through modems. Ideal for low cost RTU/SCADA applications.

and features an RS-232 and an RS-485 port for connection to SLC 500 controllers.

DH-485 network. The coupler provides a 6-position removable terminal block for connection to the DH-485 communication cable.

1747-IN006

1747-IN063

1747-UM011

1761-NET-AIC Advanced Interface

Converter

1770-KF3

1785-KA5 DH+/DH-485

1785-KA5P Standalone

1784-KTX, 1784-KTXD PC DH-485 Interface

1784-PCMK PCMCIA Interface

1761-L 1762-L 1763-L 1764-L

1756-L 1769-L 1794-L

(1)

DH-485/DF1 Interface Module

Gateway

Card

Card MicroLogix

Programmable Controllers

Logix Programmable Controllers

Standalone Provides a communication link between various

Standalone, or desktop

(1771) PLC Chassis

ISA Bus Provides DH-485 or DH+ connection. 1784-6.5.22

PCMCIA slot in computer

Standalone Programmable Controllers 1761-UM003

1756 Chassis or DIN Rail

1761-UM004

networks devices. Provides an isolated DH-485 interface for SLC 500

devices to host computers over RS-232 using full- or DF1 half-duplex protocol. Enables remote programming to an SLC 500 controller or the DH-485 network through modems.

Provides communication between stations on the PLC-5 (DH+) and SLC 500 (DH-485) networks. Lets communication and data transfer from PLC to SLC 500 on DH-485 network. Also enables software programming or data acquisition across DH+ to DH-485.

Provides DH-485 or DH+ connection. 1784-6.5.19

Programmable Controllers 1756-UM001

1770-6.5.18

1785-6.5.5 1785-1.21

1762-UM001 1763-UM001 1764-UM001

1769-UM011 1794-UM001

Publication 1756-UM532A-EN-P - May 2006

2-4 Overview of the DH-485 Network

Devices that Use the DH-485 Network

Catalog Number Description Installation

Requirement

2707-L8P1 2707-L8P2 2707-L40P1 2707-L40P2 2707-V40P1 2707-V40P2 2707-V40P2N 2707-M232P3 2707-M485P3

2711-K5A2, 2711-B5A2, 2711-K5A5, 2711-B5A5, 2711-K5A1, 2711-B5A1, 2711-K9A2, 2711-T9A2, 2711-K9A5, 2711-T9A5, 2711-K9A1, and 2711-T9A1

(1)

(1) (1)

, and

DTAM Plus and DTAM Micro Operator

Interfaces

PanelView 550 and PanelView 900 Operator Terminals

(1)

Panel Mount Provides electronic operator interface for SLC 500

Function Publication

2707-800,

controllers.

2707-803

2711-UM014DF

1784-PKTX, 1784-PKTXD

(1) This product is no longer available for order.

PC DH-485 Interface Card

1747-AIC Isolated Link Coupler for DH-485

PCI Bus Provides DH-485 or DH+ connection 1784-6.5.27

Use the isolated link coupler (1747-AIC) to connect SLC 500 family devices to the DH-485 network (as shown on page 2-5). The coupler provides a 6-position removable terminal block for connection to the DH-485 communication cable.

To establish network connections for:

• SLC 500 controllers (SLC 5/03 and below), use a 304.8 mm (12 in.) cable, supplied with the link coupler (catalog number 1747-C11).

If you need to connect a peripheral device that is between 1.8 m (6 ft) and 6.1 m (20 ft) away, use the 1747-C20 cable.

To protect connected devices, the coupler provides 1500V dc isolation between the communications cable and the attached SLC 500 controller and peripheral devices.

Publication 1756-UM532A-EN-P - May 2006

Overview of the DH-485 Network 2-5

You can also use the isolated link coupler to provide connectivity between devices for distances greater than 1.8 m (6 ft) up to a maximum of 1219 m (4000 ft). Below is an example of a remote connection between a computer running your programming software and an SLC 500 controller.

Remote Connection Between a Computer Running Programming Software and an SLC 500 Controller

RSLogix 500

Software

1747-UIC

UIC

1747-C13

1747-AIC

+24V dc

1747-AIC

>1.8m (6 ft)

1747-C11

Publication 1756-UM532A-EN-P - May 2006

2-6 Overview of the DH-485 Network

1761-NET-AIC Advanced Interface Converter Product Overview

Operating Modes

The AIC+ advanced interface converter provides a communication link between various networks devices. Ports 1, 2, and 3 are used for making the communication connections. The AIC+ is compatible with a variety of SLC and MicroLogix controllers and the 1756-DH485 communications module.

The MicroLogix controllers provide power to the AIC+ via port 2’s cable. However, if a controller is not connected to port 2, a 24V dc power supply connected to the converter’s external power terminals is required. The DC power source selector switch needs to be set for your particular configuration.

The baud rate selector switch is used to match the baud rate filter of the AIC+ to the network baud rate. This switch does not change the network baud rate and is normally left in the AUTO position. In high noise environments, the baud rate selector switch should be taken out of the AUTO mode and set to the same baud rate as the network.

The AIC+ can be used in the following modes for DH-485:

• point-to-point RS-232 isolator

• RS-232 to RS-485 isolator

Communication is established using hardware handshaking or auto transmit signals.

Device Compatibility

The AIC+ can be used to interconnect the following devices:

• SLC 500, 5/01, 5/02, and 5/03 controllers (channel 1)

• SLC 5/03, 5/04, and 5/05 controllers (channel 0)

• MicroLogix controllers

• Logix Controllers

• Operator interface devices

• PC serial ports (or any 9-pin DTE serial port)

• Logix controller serial port (DH485 mode)

• 1756-DH485 module

TIP

The 1761-HHP-B30 Hand-Held Programmer is not connectable to the AIC+ advanced interface converter.

Publication 1756-UM532A-EN-P - May 2006

Node Address Identification

Overview of the DH-485 Network 2-7

Misconception about the 1761-NET-AIC Converter

There is no node address associated with the network port (Port 3).

1 Node Address

Port (The node address is configured in the device connected to Port 1.)

Port 2 Node Address (The node address is configured connected to Port 2.)

Use this write-on area to mark the node address of each connection.

in the device

The function of the 1761-NET-AIC converter is to accomplish two tasks. The first is to convert RS232 electrical signals to RS485 electrical signals and RS485 electrical signals to RS232 electrical signals.

The second function is to provide electrical isolation between all three communication ports. This protects against ground loops and voltage differences between devices connected to the 1761-NET-AIC converter.

1747-UIC USB to DH-485 Interface Converter

A common misconception is that the 1761-NET-AIC device converts protocol, this is not true, it passes the protocol but converts the electrical signals. An example device that would convert protocol and electrical signal is the 1747-KE module.

Refer to the Isolation Interface Converter (AIC+) User Manual, publication 1761-UM004 for complete information.

The 1747-UIC lets you connect DH-485 devices directly to a computer’s USB port. It features an RS-232 port for connection to SLC 5/03 and higher controllers, MicroLogix, PanelView 300 and higher terminals, 1761-NET-AIC+, and Logix controllers, as well as an RS-485 port for connection to SLC 5/03 and lower controllers, PanelView 300 and higher terminals, and 1747-AIC. The converter can communicate with devices on the DH-485 network at 19.2K baud.

Publication 1756-UM532A-EN-P - May 2006

2-8 Overview of the DH-485 Network

Example System Configuration

Personal Computer

SLC 5/03, 5/04, or 5/05

1747-UIC Interface Converter

1747-AIC Isolated Link Coupler

Modular Controller

1761-NET-AIC Advanced Interface Converter

SLC 500 20-Point Fixed Controller

Below is an example of a DH-485 network.

Example DH-485 Network System Configuration

DH-485 Network

max. length 1219 m (4,000 ft)

1747-AIC

Data Table Access Module

SLC 5/01 Modular Controller

1747-AIC

SLC 500 20-Point Fixed Controller with 2-Slot Expansion Chassis

1747-AIC

1761-NET-AIC

SLC 500 Fixed Controller

Personal Computer

1747-AIC

SLC 5/02 Modular Controller

PanelView

ControlLogix Controller and 1756-DH485 Communications Module

44138

Publication 1756-UM532A-EN-P - May 2006

Overview of the DH-485 Network 2-9

Configure the SLC 5/03, SLC 5/04, and SLC 5/05 Controller Channel 0 for DH-485

The RS-232 port (channel 0) of the SLC 5/03, SLC 5/04, and SLC 5/05 controllers can be configured for DH-485 protocol. You can connect channel 0 of the SLC 5/03, SLC 5/04, and SLC 5/05 controllers to a DH-485 network using the 1747-CP3 cable and a 1761-NET-AIC Advanced Interface Converter (AIC+). In this case, the AIC+ must be powered with 24V dc. The 1746-P1, -P2, -P4, -P5, and -P6 power supplies provide 24V dc user power that may be used to power the AIC+

Configure an SLC Controller for DH-485.

DH-485

1747-AIC

Personal Computer

APS

SLC 5/01

1747-C11

DH-485

SLC 5/03, 5/04, or 5/05

24V dc Power Supply

1761-NET-AIC

1761-CBL-PM02 or 1747-CP3

RS-232

24V dc User Power Connection

1761-NET-AIC

1747-CP3 or 1761-CBL-PM02

24V dc User Power Connection

Publication 1756-UM532A-EN-P - May 2006

2-10 Overview of the DH-485 Network

Important Planning Considerations

Carefully plan your network configuration before installing any hardware. Listed below are some of the factors that can affect system performance:

• Amount of electrical noise, temperature, and humidity in the network environment

• Number of devices on the network

• Connection and grounding quality in installation

• Amount of communication traffic on the network

• Type of process being controlled

• Network configuration

The major hardware and software issues you need to resolve before installing a network are discussed in the following sections.

Hardware Considerations

You need to decide the length of the communication cable, where you will route it, and how to protect it from the environment where it will be installed.

Before you install the communication cable, you need to know how many devices are to be connected during installation and how many devices will be added in the future. The following sections will help you understand and plan the network.

Number of Devices and Length of Communication Cable

You must install a link coupler communications adapter (1747-AIC or 1761-NET-AIC) for each node on the network. If you plan to add nodes later, provide additional link couplers during the initial installation to avoid recabling after the network is in operation.

The maximum length of the communication cable is 1219 m (4000 ft). This is the total cable distance from the first node to the last node on the network.

Publication 1756-UM532A-EN-P - May 2006

Overview of the DH-485 Network 2-11

Plan Cable Routes

Follow these guidelines to help protect the communication cable from electrical interference:

• Keep the communication cable at least 1.52 m (5 ft) from any electric motors, transformers, rectifiers, generators, arc welders, induction furnaces, or sources of microwave radiation.

• If you must run the cable across power feed lines, run the cable at right angles to the lines.

• If you do not run the cable through a contiguous metallic wireway or conduit, keep the communication cable at least 0.15 m (6 in.) from ac power lines of less than 20A, 0.30 m (1 ft) from lines greater than 20A, but only up to 100k VA, and 0.60 m (2 ft) from lines of 100k VA or more.

• If you run the cable through a contiguous metallic wireway or conduit, keep the communication cable at least 0.08 m (3 in.) from ac power lines of less than 20A, 0.15 m (6 in.) from lines greater than 20A, but only up to 100k VA, and 0.30 m (1 ft) from lines of 100k VA or more.

Running the communication cable through conduit provides extra protection from physical damage and electrical interference. If you route the cable through conduit, follow these additional recommendations:

– Use ferromagnetic conduit near critical sources of electrical

interference. You can use aluminum conduit in non-critical areas.

– Use plastic connectors to couple between aluminum and

ferromagnetic conduit. Make an electrical connection around the plastic connector (use pipe clamps and the heavy gauge wire or wire braid) to hold both sections at the same potential.

– Ground the entire length of conduit by attaching it to the building

earth ground.

– Do not let the conduit touch the plug on the cable.

– Arrange the cables loosely within the conduit. The conduit should

contain only serial communication cables.

– Install the conduit so that it meets all applicable codes and

environmental specifications.

For more information on planning cable routes, see Industrial Automation Wiring and Grounding Guidelines, Publication Number 1770-4.1.

Publication 1756-UM532A-EN-P - May 2006

2-12 Overview of the DH-485 Network

Software Considerations

Software considerations include the configuration of the network and the parameters that can be set to the specific requirements of the network. The following are major configuration factors that have a significant effect on network performance:

• Number of nodes on the network

• Addresses of those nodes

• Baud rate

• Maximum node address selection

• SLC 5/03, SLC 5/04, and SLC 5/05 controllers only: token hold factor

• Maximum number of communicating devices

The following sections explain network considerations and describe ways to select parameters for optimum network performance (speed).

Number of Nodes

The number of nodes on the network directly affects the data transfer time between nodes. Unnecessary nodes (such as a second programming terminal that is not being used) slow the data transfer rate. The maximum number of nodes on the network is 32.

Set Node Addresses

The best network performance occurs when node addresses start at 0 and are assigned in sequential order. Controllers cannot be node 0. Also, initiators such as personal computers should be assigned the lowest numbered addresses to minimize the time required to initialize the network.

Set Controller Baud Rate

The best network performance occurs at the highest baud rate. All devices must be at the same baud rate.

Publication 1756-UM532A-EN-P - May 2006

+ 80 hidden pages