Rockwell Automation 1747-DCM, D17476.8 User Manual

Allen-Bradley

Direct Communication

User

Module

(Cat. No. 1747-DCM)

Manual

Important User Information

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) 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 the Allen-Bradley Company 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, the Allen-Bradley Company cannot assume responsibility or liability for actual use based on the examples and diagrams.

No patent liability is assumed by Allen-Bradley Company 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 the Allen-Bradley Company is prohibited.

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

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 the hazard

• recognize the consequences

Important: Identifies information that is especially important for successful

application and understanding of the product.

PLC, PLC-2, PLC-3, and PLC-5 are registered trademarks of Allen-Bradley Company, Inc. SLC, SLC 500, Dataliner, PanelView, RediPANEL, PLC-5/11, PLC-5/15, PLC-5/20, PLC-5/12, PLC-5/25, PLC-5/30, PLC-5/40, PLC-5/60 are trademarks of Allen-Bradley Company, Inc. IBM is a registered trademark of International Business Machines, Incorporated.

Summary of Changes

The information below summarizes the changes to this manual since the last printing as 1747-NM007–September 1993.

To help you find new information and updated information in this release of the manual, we have included change bars as shown to the right of this paragraph.

New Information

The table below lists sections that document new features and additional information about existing features, and shows where to find this new information.

For This New Information See

Related documentation updated preface Quick Start for Experienced Users chapter 2 Default DIP switch settings chapter 4 CE certification chapter 5, appendix A DCM clear on fault DIP switch chapter 6

able of Contents

Direct Communication Module User Manual

Preface

Who

Should Use this Manual

Purpose

Terms Common Allen-Bradley

of this Manual Contents Related

Local

Technical Product Assistance P–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Your Questions or Comments on this Manual P–5. . . . . . . . . . . . . . . . . . . . .

of this Manual

Documentation

and Abbreviations

Techniques Used in this Manual

Support

Product Support

P–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

P–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

P–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

P–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

P–5. . . . . . . . . . . . . . . . . . . . . . . . . .

P–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

P–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Overview

Quick Start for Experienced Users

Addressing

Chapter 1

Hardware Overview 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

System Overview 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

What

Is a Remote I/O Adapter?

Extended

Scanner Image Division 1–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Scanner

Data Exchange Between RIO Scanners and the DCM 1–6. . . . . . . . . . . . . . . . .

What

Node Capability

Image Division Configuration Example

Is the Status W

ord? 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter 2

Required Tools and Equipment

Procedures 2–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter 3

Addressing

PLC/Scanner Addresses 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SLC Addresses 3–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

I/O

Image

Ladder Logic Instructions

Image T

PLC to DCM/SLC 3–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DCM/SLC

Mapping

ables 3–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

to PLC

1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1–5. . . . . . . . . . . . . . . . . . .

2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Module Configuration

Chapter 4

DIP Switches 4–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DIP

Switch 1 Settings Starting Rack

DIP

Rack

Last Rack (SW2-4) 4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Clear Data

I/O Group Number (SW1-7 and SW1-8)

Address (SW1-1 through SW1-6)

Switch 2 Settings

Size (SW2-5 and SW2-6))

On Fault (SW2-3)

Rate (SW2-1 and SW2-2)

4–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4–2. . . . . . . . . . . . . . . . . . .

4–3. . . . . . . . . . . . . . . . . . . . . . . . .

4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

able of Contents

Direct Communication Module User Manual

Installation and Wiring

Programming

Chapter 5

Compliance

EMC Directive 5–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DCM

Installation 5–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Removal 5–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Network

to European Union Directives

Installation

Wiring

Chapter 6

Overview 6–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Programming Examples 6–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Physical Physical Physical

Physical

Status Words 6–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

RIO DCM/SLC

Applications Using I/O Status W

RIO

DCM/SLC

RIO

Input into PLC – Physical Output from SLC Input into SLC – Physical Output from PLC Input into Both PLC and SLC (Logical AND) –

Physical Output from SLC 6–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Input into First SLC – Physical Output from Second SLC

Scanner Input Status W

Output Status W

Scanner Status W

Using

the Program/T

Output Status W

Using

the Data Invalid Bit

Using

the User Status Flag Bit

Scanner Input Status and DCM/SLC Output Status

Using

the Logical OR Bit

ord Examination (Decimal) 6–5. . . . . . . . . . . . .

ord Examination (Octal) 6–6. . . . . . . . . . . . . . . .

ord Bits

ord 6–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

est/Fault Mode Bit

ord 6–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5–1. . . . . . . . . . . . . . . . . . . . . . . . . .

5–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6–2. . . . . . . . . . . . . . . .

6–3. . . . . . . . . . . . . . . .

6–4. . . . . .

6–7. . . . . . . . . . . . . . . . . . . . . . . . . . . .

6–7. . . . . . . . . . . . . . . . . . . . . . .

6–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6–10. . . . . . . . . . . . .

6–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Troubleshooting

Application Examples

Chapter 7

DCM

Status Indicators Troubleshooting

Troubleshooting Using the COMM LED (Green) 7–2. . . . . . . . . . . . . . . . . . . . . .

Using the F

AULT LED (Red) 7–1. . . . . . . . . . . . . . . . . . . . . . . .

Chapter 8

Basic Example 8–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1747-SN DIP System System Image Program

Supplementary Example 8–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Module DIP System Image

Module Configuration

Switch Settings

Configuration for Rack 1 Configuration for Rack 2

able Configuration

Listing

Configuration

Switch Settings

Configuration

able Configuration

7–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

able of Contents

Direct Communication Module User Manual

Specifications

DCM Addressing Worksheet

Program Program

Listing for 5/01 Listing for PLC5/15

Appendix A

Electrical Environmental Network Throughput

Specifications

iming A–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Appendix B

Directions B–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Addressing Review B–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

PLC Addresses B–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SLC Addresses B–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

A–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

A–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

A–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

iii

Preface

Read this preface to familiarize yourself with the rest of the manual. This preface covers the following topics:

• who should use this manual

• the purpose of this manual

• terms and abbreviations

• conventions used in this manual

• Allen–Bradley support

Who Should Use this Manual

Purpose of this Manual

Use this manual if you are responsible for designing, installing, programming, or troubleshooting control systems that use Allen–Bradley small logic controllers.

You should have a basic understanding of SLC 500t products. You should understand programmable controllers and be able to interpret the ladder logic instructions required to control your application. If you do not, contact your local Allen–Bradley representative for information on available training courses before using this product. If using Advanced Programming

Software (APS), we recommend that you review The APS Quick Start for New Users, Publication 9399-APSQS.

This manual is a reference guide for the Direct Communication Module (DCM). It describes the procedures you use to address, configure and program the DCM for application with PLCs and SLCs.

P–1

Preface

Contents of this Manual

Chapter Title Content

Describes the purpose, background, and scope of

Preface

1 Overview

this manual. Also specifies the audience for whom this manual is intended.

Provides a hardware and system overview including physical features, system communication, scanner

image division and communications flow. 2 3 Addressing Explains slot numbering and image mapping.

4 Module Configuration Provides DIP switch setting information. 5 Installation and Wiring

6 Programming

7 Troubleshooting Describes troubleshooting using front panel LEDs. 8 Application Examples

Appendix A Specifications

Appendix B DCM Addressing Worksheet

Quick Start

for Experienced Users

Serves as a Quick Start Guide for using the DCM.

Provides installation procedures and a wiring

diagram.

Shows how to program ladder logic in the PLCr

and the SLC 500, including an examination of

special programming instructions that affect system

response. Also examines the status word and its

applications.

Provides and examines both basic and

supplementary applications.

Provides module and system specifications and

discusses throughput.

Helps you to work out the image table configuration

for DCMs in your system.

P–2

Preface

Terms and Abbreviations

The following terms and abbreviations are specific to this product. For a complete listing of Allen–Bradley terminology, refer to the Allen–Bradley Industrial Automation Glossary, Publication Number ICCG–7.1.

Adapter – Any physical device that is a slave on the RIO link. Adapter Image – The portion of scanner image assigned to an individual

adapter. You configure the adapter image by assigning it a starting logical rack number, starting logical group number and the number of logical groups it uses. In the case of the DCM, this is referred to as the DCM image.

DCM – Refers to the Direct Communication Module. Distributed Control/Controller – Refers to a control system that employs a

number of different hardware controllers/processors, each designed to perform a different subtask on behalf of an overall program or process. In a single processor (non–distributed) system, each task would be done by the single processor controlling the process. In a distributed system, each task is targeted to the specific processor required to perform its needs. Since all processors run simultaneously and independently, the time required to perform each task of the overall process is reduced in comparison to a single processor system. Therefore, overall program or process performance is typically better.

Inhibit – A function by which the scanner stops communicating with a logical device. The logical device will consider itself inhibited if it does not receive communications from the scanner within a certain period of time.

Logical Device Logical Group – A logical group consists of one input and one output word

within a logical rack. A word consists of 16 bits, each bit represents one terminal on a discrete I/O module. Also referred to as an I/O Group.

Logical Rack – A fixed section of the scanner image comprised of eight input words and eight output words. Also referred to as a rack.

Logical Slot – A logical slot consists of one input and one output byte within a logical group. A byte consists of 8 bits, each bit represents one terminal on a discrete I/O module.

Physical Device – The number of devices that the supervisory processor/ scanner will support.

PLC Chassis – A physical PLC (Programmable Logic Controller) rack that houses PLC processors and 1771 I/O modules.

– Any portion of a logical rack assigned to a single adapter.

P–4

Preface

Rack Size – The logical rack size of the DCM image. RIO Link – (Remote Input/Output) Refers to an Allen–Bradley

communication system supporting high–speed serial transfer of Remote I/O (RIO) control information.

Scanner – The communication master on the RIO link. Scanner Image – The data table area within the scanner, used to exchange

I/O information between the scanner and all the adapters on the RIO link. The scanner image is a portion of the SLC or PLC processor image.

Slave – In a communication link, a station that cannot initiate communication.

SLC Chassis – A physical SLC (Small Logic Controller) rack that houses SLC processors and 1746 and 1747 I/O modules.

Slot – The physical location in any chassis used to insert I/O (or specialty) modules.

Common Techniques Used in this Manual

Supervisory Control/Controller – A control system whereby a host (supervisory) controller/processor monitors and intermittently adjusts control parameters, as necessary, of one or several lower level processors while the lower level processor(s) performs the control task continuously in real time.

The following conventions are used throughout this manual:

• Bulleted lists such as this one provide information, not procedural steps.

• Numbered lists provide sequential steps or hierarchical information.

• Italic type is used for emphasis.

P–5

Preface

Allen–Bradley Support

Allen–Bradley offers support services worldwide, with over 75 Sales/Support Offices, 512 authorized Distributors and 260 authorized Systems Integrators located throughout the United States alone, plus Allen–Bradley representatives in every major country in the world.

Local Product Support

Contact your local Allen–Bradley representative for:

• sales and order support

• product technical training

• warranty support

• support service agreements

Technical Product Assistance

If you need to contact Allen–Bradley for technical assistance, please review the information in the Troubleshooting chapter first. Then call your local Allen–Bradley representative.

Your Questions or Comments on this Manual

If you find a problem with this manual, please notify us of it on the enclosed Publication Problem Report.

If you have any suggestions for how this manual could be made more useful to you, please contact us at the address below:

Allen–Bradley Company, Inc. Automation Group Technical Communication, Dept. 602V, T122 P.O. Box 2086 Milwaukee, WI 53201–2086

P–6

Chapter

are Overvie

Overview

This chapter provides a hardware and system overview including physical features and connectivity illustrations. It also explains data exchange between processors and discusses rack size. Topics include:

• hardware overview

• system overview

• scanner image division

• communications flow

Hardw

FAULT LED

(Red)

COMM LED

(Green)

Door Label

Front Label

RIO Link Connector

Cable Tie Slots

The Direct Communication Module, Catalog Number 1747–DCM, is used to connect an SLC 500 Fixed Programmable Controller with expansion chassis or any SLC 500 Modular Programmable Controller to a supervisory Allen–Bradley Programmable Controller via the RIO Link, thereby providing a distributed processing system. The DCM occupies one slot in any SLC 500 chassis.

Self–Locking Tab

Side Label

DIP Switches

DCM FAULT COMM

CONFIGURATION

RACK ADDR

RACK SIZE

1/4 1/2 3/4 1

FIRST I/O GROUP 0 2 4 6

DATA RATE (K B/S)

57.6 115.2 230.4

LINE 1 _______ SHIELD ______ LINE 2 _______

SW1

SW2

1747–DCM

I/O

GROUP

(LSB)

RACK

ADDRESS

2345678

(MSB)

X X

RACK

SIZE

LAST

RACK

CLR ON FL

2345678

DATA RATE

2345678 1

SW1 SW2

SERIAL NO.

SW 1

I/O

GROUP

(LSB)

RACK ADDR

(MSB)

SW 2

RACK SIZE

LAST

CLR ON FL

MADE IN USA

DATA RATE

CAT

MODULE

X X

RACK

DIRECT COMMUNICATION

SLC 500

8 7 6 5 4 3 2 1

Self–Locking Tab

Hardware Features

Hardware

Function

FAULT LED Displays operating status COMM LED Displays communication status Front, Side and Door Labels Provide module configuration information RIO Link Connector Provides physical connection to RIO network Cable Tie Slots Secure and route wiring from module DIP Switches Establish configuration parameters for the module Self–Locking Tabs Secure module in chassis slot

1–1

Chapter 1

stem Overvie

Overview

Supervisory PLC or SLC

The Direct Communication Module is an SLC 500 family Remote I/O (RIO) adapter. It allows supervisory processors, such as PLC–5s, and distributed SLC–500 processors residing on an Allen–Bradley RIO Communication Link to transfer data between each other. The DCM appears as an RIO adapter to:

• a PLC processor with integral RIO scanner on the RIO Communication

Link

• an RIO scanner, Catalog Number 1771–SN or 1747–SN, on the RIO

Communication Link

RIO

Scanner

PanelViewt

(adapter)

Distributed SLCs with DCMs (adapters)

RIO Communication Link

DCM 1

DCM 2

DCM 3

DCM modules are connected in a daisy–chain configuration using Belden 9463 cable.

What Is a Remote I/O Adapter?

A remote I/O adapter (RIO adapter) is any module that acts as a slave to an RIO scanner, the master on the RIO link. The DCM is an RIO adapter.

All RIO scanners have defined physical and logical specifications. Physical specifications are the maximum number of adapters that can be connected to the scanner. (See Extended Node Capability on page 1–4.) Logical specifications are the maximum number of logical racks the scanner can address, the ways logical racks can be assigned, and the ability of the scanner to perform block transfers. Refer to the appropriate scanner manual for details concerning physical and logical specifications.

The DCM can physically reside on the RIO link with any other adapter. The following table lists the adapters available for use with an RIO link.

1–2

Chapter 1

Overview

Compatible

Number

1785-LT/x PLC-5/15 Yes In adapter mode 1785-LT2 PLC-5/25 Yes In adapter mode 1785-LT3 PLC-5/12 Yes In adapter mode 1785-L30x PLC-5/30 Yes In adapter mode 1785-L40x PLC-5/40 Yes In adapter mode 1785-L60x PLC-5/60 Yes In adapter mode 1771-ASC Remote I/O Adapter Module No

1771-ASB Remote I/O Adapter Module

1771-AM1

1771-AM2

1784-F30D 1771-RIO Remote I/O Interface Module No

Catalog

Adapters

Device

1-Slot I/O Chassis with Integral Power Supply and Adapter

2-Slot I/O Chassis with Integral Power Supply and Adapter

Plant Floor Terminal Remote I/O Expansion Module

Extended

Node

Capability

Series B and

C only

Yes

Comments

Series A, B, and C

1771-JAB Single Point I/O Adapter Module Yes 1771-DCM Direct Communication Module No 1778-ASB Remote I/O Adapter Module Yes 1747-ASB Remote I/O Adapter Module Yes

2706-xxxx 2705-xxx

2711-xx PanelView Terminal Yes 1336-RIO

1395-NA

1747-ASB

DL40 Datalinert RediPANELt

Remote I/O Adapter for 1336 AC Industrial Drives

Remote I/O Adapter for 1395 DC Industrial Drives

SLC 500 Remote I/O Adapter Module

Yes Yes

Yes

Must be catalog number 2706-ExxxxxB1.

1–3

Chapter 1

canner Image

Overview

Extended Node Capability

Both scanners and adapters can have extended node capability. Extended node capability allows you to have up to 32 adapters on the RIO link using an 82 Ohm termination resistor at both ends of the RIO link for all baud rates.

Extended node capability can only be used if the scanner and all adapters on the RIO link have extended node capability. The DCM has extended node

capability.

Divisi

The scanner allows each adapter to use a fixed amount (user defined) of its input and output image.

The scanner image is divided into logical racks and further divided into logical groups. A full logical rack consists of eight input and eight output image words. A logical group consists of one input and one output word in a logical rack. Each logical group is assigned a number from 0–7. The number of racks available for data and I/O transfer depends on the scanner you are using.

Local I/O

Logical Rack 0

Remote I/O

(Scanner

Image)

Processor I/O Image Scanner I/O Image Adapter

Logical Rack 1

Logical

Rack 2

Logical Rack 3

Logical Group 0

Logical

Group 7

Image

1–4

The scanner image also contains the image of each adapter on the RIO link. The adapter is assigned a portion of the scanner image, which is referred to as the adapter image.

Chapter 1

Overview

Scanner Image Division Configuration Example

The example presented here can help you configure your RIO architecture. Refer to it as necessary.

The following figure shows how a portion of a scanner’s input image table might be configured. An output image table would be identically configured.

Logical

Rack

Logical

Rack

Logical

Rack 2

Decimal Bit Number

Octal Bit Number

Rack 0 Group 0

Rack 0 Group 1

Rack 0 Group 2

Rack 0 Group 3

Rack 0 Group 4

Rack 0 Group 5

Rack 0 Group 6

Rack 0 Group 7

Rack 1 Group 0

Rack 1 Group 1

Rack 1 Group 2

Rack 1 Group 3

Rack 1 Group 4

Rack 1 Group 5

Rack 1 Group 6

Rack 1 Group 7

Rack 2 Group 0

Rack 2 Group 1

Rack 2 Group 2

Rack 2 Group 3

Rack 2 Group 4

Rack 2 Group 5

Rack 2 Group 6

Rack 2 Group 7

Word 0

Word 1

Word 2

Word 3

Word 4

Word 5

Word 6

Word 7

Word 8

Word 9

Word 10

Word 11

Word 12

Word 13

Word 14

Word 15

Word 16

Word 17

Word 18

Word 19

Word 20

Word 21

Word 22

Word 23

0123456789101112131415 012345671011121314151617

Device

(Full logical rack)

Device 2

(3/4 logical rack)

Device 3

(1/4 logical rack)

Device

(1/2 logical rack)

Important: The configured image size of a DCM cannot cross logical rack

boundaries; it cannot use a portion of rack 0 and a portion of rack 1.

1–5

Chapter 1

Overview

Data Exchange Between RIO Scanners and the DCM

Processor Scan

Supervisory PLC or SLC

Information is transferred between the RIO scanner and the DCM every RIO scan. RIO transmissions are asynchronous to the processor scans.

Important: The DCM provides word integrity on all words transferred via

the SLC backplane.

The DCM communicates with supervisory PLC or SLC controllers through RIO scanners, as if they were addressing a logical rack. However, the DCM does not scan the I/O in its local I/O chassis, rather it passes the supervisory data to the distributed SLC processor.

In the DCM, outputs from the SLC output image table are inputs to the supervisory processor input image table. Likewise, outputs from the supervisory processor output image table are inputs to the SLC input image table.

The diagram that follows depicts the communications flow between an RIO scanner and the DCM.

Distributed Processor Scan

SLC Distributed

Scanner

RIO Scan

Processor

DCM

I/O Module

Outputs from PLC, Input Data to DCM

SLC Expansion

Chassis

Outputs from Modules

Output Device

Inputs to PLC, Output Data from DCM

SLC Chassis

Inputs to Modules

Input Device

What Is the Status Word?

The first word of the DCM input and output image is the status word. The status word indicates the status of communication and data between the RIO scanner and the DCM. For more information on status words and their applications, see chapter 6, Programming.

1–6

Chapter

Quick Start for Experienced Users

This chapter helps you to get started using the Direct Communication Module (DCM). We base the procedures here on the assumption that you have a basic understanding of SLC 500 products.

You must:

• understand electronic process control

• be able to interpret the ladder logic instructions for generating the

electronic signals that control your application

Because it is a start-up guide for experienced users, this chapter does not contain detailed explanations about the procedures listed. It does, however, reference other chapters in this book where you can get more detailed information. It also references other documentation that may be helpful if you are unfamiliar with programming techniques or system installation requirements.

Required Tools and Equipment

If you have any questions, or are unfamiliar with the terms used or concepts presented in the procedural steps, always read the referenced chapters and other recommended documentation before trying to apply the information.

This chapter:

• tells you what tools and equipment you need

• lists preliminary considerations

• describes when to address, configure and program the module

• explains how to install and wire the module

• discusses system power-up procedures

Have the following tools and equipment ready:

• medium blade screwdriver

• (2) 1/2 watt terminating resistors (See chapter 5, Installation and Wiring,

for correct size.)

• programming equipment (All programming examples shown in this

manual demonstrate the use of Allen-Bradley’s Advanced Programming Software [APS] for personal computers.)

2–1

Chapter 2

Quick Start for Experienced Users

Procedures

Check

the contents of the shipping box.

Unpack the module making sure that the contents include:

• Direct Communication Module (Catalog Number 1747-DCM)

• removable connector (factory-installed on module)

• cable tie

• user manual (Catalog Number 1747-NM007)

If the contents are incomplete, call your local Allen-Bradley representative for assistance.

Select

a scanner

To begin configuration of your RIO system, you should know three things:

• which scanner is compatible with your PLC/SLC controller. Use the table below to select a

scanner that is compatible with your processor. The DCM is compatible with all RIO scanners.

Catalog Number

➀

1747-SN

➁

1771-SN 1772-SD, -SD2

➂➃

1775-S4A, -S4B, -S5 1775-SR, -SR5 1785-L11B 1785-LT/x 1785-L20B 1785-LT2 1785-L30x 1785-L40x 1785-L60x 5250-RS 6008-SI 6008-SV

➀

➀➄

➀

➀➄

➀ ➀ ➀

➀

SLC Remote I/O Scanner Sub I/O scanner for Mini–PLC-2r and PLC-5 families Remote scanner/distribution panel for PLC-2 family I/O scanner-programmer interface module for PLC-3r family Remote scanner/distribution panel for PLC-3/10 family PLC 5/11t (in scanner mode)

PLC 5/15 (in scanner mode) PLC 5/20t (in scanner mode) PLC 5/25 (in scanner mode) PLC 5/30t (in scanner mode) PLC 5/40t (in scanner mode) PLC 5/60t (in scanner mode) Remote scanner for PLC 5/250 IBMr PC I/O Scanner Module VMEbus I/O Scanner Module

6008-SQH1, -SQH2 Q-bus I/O Scanner Module

Description

Reference

–

Reference

The manual for

the scanner you

select

2–2

➀

Extended

➁

Revision D or later

➂

Rev

➃

Extended node capability not available with Series A.

➄

node capability

. 3 or later

Rev.

3 or later

PLC 5/25 Series A Revision D or later have partial rack addressing. Earlier versions are limited to 7 devices.

.PLC 5/15 Series B Revision H or later have partial rack addressing. Earlier versions are limited to 3 devices.

Chapter 2

Quick Start for Experienced Users

• the maximum number of physical devices and logical racks your scanner supports.

• the logical rack size of each DCM. This depends on how many I/O data words you need to transfer. The first word

is always the status word. The table below shows the number of data words transferred relative to the rack size.

If you configure the DCM as:

1/4 Rack

1/2 Rack

3/4 Rack

Full Rack

Select DCM addressing. (A configuration worksheet is included in appendix B to assist you in DCM image table addressing.)

Choose

Configure your system by setting the DIP switches.

the type of slot addressing you will use.

Configure

Insert

the 1747-DCM module into the chassis.

1 data word (16 bits of I/O

3 data words (48 bits of I/O

5 data words (80 bits of I/O

7 data words (112 bits of I/O

the module using the DIP switches.

Then: Including the Status Word

data) are transferred.

Total transfer = 2 words

Total transfer = 4 words

Total transfer = 6 words

Total transfer = 8 words

Reference

Chapter 3

(Addressing)

Appendix B

(DCM Worksheet)

Reference

Chapter 4

(Module

Configuration)

Reference

ATTENTION: Never install, remove, or wire modules with power applied to the chassis or

devices wired to the module.

SLC/DCM power requirements to ensure your SLC power supply has adequate reserve power

Review Make sure system power is off; then insert the DCM into your 1746 chassis. In this example

procedure, local slot 1 is selected.

Module Release

Card Guide

. . .

Cable Tie

Chapter 5

(Installation and

Wiring)

2–3

Chapter 2

Usin

xtende

apabilit

xtende

Quick Start for Experienced Users

To wire the network, a 1/2 watt terminating resistor must be attached across line 1 and line 2 of the connectors at each end (scanner and last physical device) of the network. The size of the resistor depends on the baud rate and extended node capability, as shown below:

Baud Rate

g E

Node C

Not Using E

d Nod

Capability

Define the application requirements. Write and enter the ladder logic program.

Power up your system by performing standard start-up procedures as indicated in your processor manual. No special start-up procedures are required when using the DCM module.

57.6K baud 3048 meters (10,000 feet)

115.2K baud 1524 meters (5,000 feet)

230.4K baud

57.6K baud 3048 meters (10,000 feet)

115.2K baud 1524 meters (5,000 feet)

230.4K baud 762 meters (2,500 feet)

Enter

through the system start-up procedure.

Maximum Cable Distance

(Belden 9463)

762 meters (2,500 feet)

your ladder program.

Resistor Size

2W 1/2 Watt

Brown–Green–Brown–Gold

50W 1/2 Watt

Brown–Green–Brown–Gold 82W 1/2 Watt

Gray–Red–Black–Gold

Reference

Chapter 6

(Programming)

Chapter 8

(Application

Examples)

Reference

–

2–4

+ 56 hidden pages