Allen-Bradley 1747-BSN Backup Scanner User Manual

Below you will find brief information for Backup Scanner 1747-BSN. This manual describes the installation, configuration, operation, and programming of the 1747-BSN Backup Scanner Module, which is used with Allen-Bradley SLC 500 processors and other compatible devices. You will learn about the module’s features, how to connect it to your system, and how to configure it for optimal performance.

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Backup Scanner

1747-BSN

User Manual

Important User Information

Because of the variety of uses for the products described in this publication, those responsible for the application and use of this control equipment must satisfy themselves that all necessary steps have been taken to assure that each application and use meets all performance and safety requirements, including any applicable laws, regulations, codes and standards.

The illustrations, charts, sample programs and layout examples shown in this guide are intended solely for purposes of example.

Since there are many variables and requirements associated with any particular installation, Allen-Bradley does not assume responsibility or liability (to include intellectual property liability) for actual use based upon the examples shown in this publication.

Allen-Bradley publication SGI-1.1, Safety Guidelines for the

Application, Installation and Maintenance of Solid-State Control

(available from your local Allen-Bradley office), describes some important differences between solid-state equipment and electromechanical devices that should be taken into consideration when applying products such as those described in this publication.

Reproduction of the contents of this copyrighted publication, in whole or part, without written permission of Allen-Bradley Company,

Inc., 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.

Attention statements help you to:

• identify a hazard

• avoid a hazard

• recognize the consequences

Important:

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

Publication 1747-6.22

Overview

Table of Contents

Preface

Who Should Use This Manual . . . . . . . . . . . . . . . . . . . . . . . . . P-1

How to Use This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-1

Manual Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-1

Related Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-2

Conventions Used in This Manual . . . . . . . . . . . . . . . . . . . . . . P-3

Allen-Bradley Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-3

Local Product Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-3

Technical Product Assistance . . . . . . . . . . . . . . . . . . . . . . . P-3

Your Questions or Comments on the Manual . . . . . . . . . . . P-3

Chapter 1

System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Scanner I/O Image Division . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

How the Scanner Scans Remote I/O . . . . . . . . . . . . . . . . . . . . 1-4

SLC and Scanner Asynchronous Operation . . . . . . . . . . . . . . 1-5

How the Scanner Interacts with Adapters . . . . . . . . . . . . . . . . 1-6

Scanner I/O Image Concepts. . . . . . . . . . . . . . . . . . . . . . . . 1-6

Example Scanner I/O Image. . . . . . . . . . . . . . . . . . . . . . 1-7

Transferring Data with RIO Discrete and Block Transfers 1-8

Physical and Logical RIO Link Specifications . . . . . . . . . 1-9

Extended Node Capability . . . . . . . . . . . . . . . . . . . . . . . 1-9

Complementary I/O. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

Guidelines for Configuring Complementary I/O . . . . . . 1-10

Complementary I/O: Placing Modules with

2-Slot Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11

Complementary I/O: Placing Modules with

1-Slot Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12

Complementary I/O: Placing Modules with 1/2-Slot

Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13

Summary for Placing Modules Used In

Complementary I/O . . . . . . . . . . . . . . . . . . . . . . . . . 1-13

Discrete Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13

Block Transfer Modules. . . . . . . . . . . . . . . . . . . . . . . . . 1-14

Complementary I/O Application Considerations . . . . . . 1-16

Complementary 1771 I/O Module Details. . . . . . . . . . . 1-16

Hardware Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17

Status LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17

Configuration Dip Switch Settings . . . . . . . . . . . . . . . . . . . 1-18

Module Address Switch . . . . . . . . . . . . . . . . . . . . . . . . 1-19

Compatible Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-19

Backup Concepts for the SLC 500 System . . . . . . . . . . . . . . 1-20

Why Use a Backup System? . . . . . . . . . . . . . . . . . . . . 1-20

Applying 1747-BSN Backup Scanner Modules

to the SLC-500 Programmable Controller . . . . . . . . 1-20

A Typical SLC 500 Backup Configuration . . . . . . . . . . . 1-21

Publication 1747-6.22

Table of Contents

How the SLC 500 Backup System Works. . . . . . . . 1-22

Chapter 2 Quick Start for Experienced Users

Required Tools and Equipment . . . . . . . . . . . . . . . . . . . . . 2-1

Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Chapter 3 Installation and Wiring

Compliance to European Union Directives . . . . . . . . . . 3-1

EMC Directive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Configuration Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Baud Rate Settings. . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Module Address Switch . . . . . . . . . . . . . . . . . . . . . . 3-2

Backup Scanner Installation . . . . . . . . . . . . . . . . . . . . . 3-3

Insertion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

Terminal Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

Status LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

Chapter 4 Operating Your SLC 500

Backup System

Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

How the 1747-BSN Module Operates . . . . . . . . . . . . . . . . 4-1

Automatic Transfer of Remote Input Data

Over the HSSL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

RS-232/485 Communication Channel . . . . . . . . . . . 4-2

RIO/DH+ Communication Channel. . . . . . . . . . . . . . 4-2

Secondary Processor Remote Programming . . . . . . 4-4

Data Table Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

How the Backup System Operates . . . . . . . . . . . . . . . . . . 4-5

Primary Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

Secondary Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

Backup System Theory of Operation . . . . . . . . . . . . . . . 4-6

Startup Sequencing . . . . . . . . . . . . . . . . . . . . . . . . . 4-7

Power-up Sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7

Processor Mode Change Sequencing . . . . . . . . . . . . . . . . 4-7

Fail-over Sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

Power Down Sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

Restarting a failed system . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

Publication 1747-6.22

Table of Contents vii

Chapter 5 Scanner Configuration and

Programming

Understanding Remote Input and Output Image Files . . . 5-1

RIO Configuration Using G Files . . . . . . . . . . . . . . . . . . 5-2

Rules for Configuring the Scanner . . . . . . . . . . . . . . . . . . . 5-5

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5

Concerning Complementary I/O . . . . . . . . . . . . . . . 5-5

Considerations When Configuring Remote I/O . . . . . . . . . 5-9

G File Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9

Crossing Logical Rack Boundaries . . . . . . . . . . . . . . . . . . 5-9

Examples of Crossing Logical Rack Boundaries. . . . . . 5-9

Understanding M Files . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10

M Files Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10

M0 Control File Description . . . . . . . . . . . . . . . . . . . . . 5-13

M0 File - RIO Device Inhibit Control . . . . . . . . . . . . . . . . 5-14

M0 File - RIO Device Reset Control . . . . . . . . . . . . . . . . 5-15

M0 File - Remote Output Reset Control . . . . . . . . . . . . . 5-16

Device Reset and Remote Output Reset

Considerations From this mode . . . . . . . . . . . . 5-17

M1 Status File Description . . . . . . . . . . . . . . . . . . . . . . . . 5-19

General Communication Status - Enable Device

Fault Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19

General Communication Status - Communication

Attempted Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20

RIO Baud Rate Status . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20

Logical Device Starting Address Status . . . . . . . . . . . . . . 5-21

Logical Device Image Size Status . . . . . . . . . . . . . . . . . . 5-21

Active Device Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22

Logical Device Fault Status . . . . . . . . . . . . . . . . . . . . . . . 5-23

RIO Status Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25

SLC/Scanner Configuration . . . . . . . . . . . . . . . . . . . . . . . 5-29

Chapter 6 Module Control and Status

Word

System Status Word . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2

Module Status Word . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4

Transferring Data over the High-Speed Serial Link

(HSSL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5

Data Transfer Control Word . . . . . . . . . . . . . . . . . . . . . . . . 6-6

Data Transfer Status Word . . . . . . . . . . . . . . . . . . . . . . . . 6-7

Data Transfer Handshake Word . . . . . . . . . . . . . . . . . . . . 6-8

Program File 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-9

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viii

Table of Contents

RIO Block Transfer

Program File 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10

Program File 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11

Switch Assemblies Status Word . . . . . . . . . . . . . . . . . . . . 6-12

Module Status Counters . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13

Data Block Counters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-14

Chapter 7

RIO Block Transfer Theory of Operation . . . . . . . . . . . . . . 7-1

What Is RIO Block Transfer? . . . . . . . . . . . . . . . . . . . . . 7-1

RIO Block Transfer General Functional Overview . . . . . . . 7-5

Scanner I/O Image Allocation For Block Transfer . . . . . 7-6

Examples of BT I/O Image File Allocation . . . . . . . . . . . 7-6

Scanner’s Block Transfer Buffer Layout . . . . . . . . . . . . . . . 7-8

M0 File - Block Transfer Output/Control Buffers . . . . . . 7-8

M0 File BT Control Buffer Layout . . . . . . . . . . . . . . . 7-9

BT Control Flag Definitions . . . . . . . . . . . . . . . . . . . 7-9

M1 File - Block Transfer Input/Status Buffers . . . . . . . . 7-9

M1 File - Input/Status BT Buffer Layout

(M1:e.100... M1:e.3200). . . . . . . . . . . . . . . . . . . 7-10

M1 File - BTR/BTW Error Codes (M1:e.103 ...

M1:e.3203) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10

M1 File - BTR/BTW Status Flag Definitions

(M1:e.100 ... M1:e.3200) . . . . . . . . . . . . . . . . . . 7-11

Detailed Operation of RIO Block Transfer . . . . . . . . . . . . 7-12

Block Transfer Timing Diagrams . . . . . . . . . . . . . . . . . 7-14

Successful Block Transfer. . . . . . . . . . . . . . . . . . . . 7-14

Successful Block Transfer Read/Write . . . . . . . . . . 7-14

Block Transfer Failure at Startup. . . . . . . . . . . . . . . 7-15

Block Transfer Failure After Startup of

Transmission Across RIO Link . . . . . . . . . . . . . . 7-16

Block Transfer Failure after Startup of

Transmission Across the RIO Link . . . . . . . . . . . 7-16

SLC Control Program Cancelling a Block

Transfer Once Transmitted Across RIO Link . . . 7-17

SLC Control Program Canceling a BT Once

Transmitted Across RIO Link . . . . . . . . . . . . . . . 7-17

SLC Control Program Cancelling a Block

Transfer Prior To Transmission Across RIO Link 7-18

SLC Control Program Canceling a BT Prior to

Transmission Across RIO Link . . . . . . . . . . . . . . 7-18

Setting Up A Block Transfer . . . . . . . . . . . . . . . . . . . . . . . 7-20

Quick Reference to Status and Control Bits . . . . . . . . . . . 7-20

Status Bits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-20

Control Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-21

Block Transfer Read Control Logic Example . . . . . . . . . . 7-21

Directional Continuous Block Transfer Example . . . . . 7-27

Directional Repeating Block Transfer Example . . . . . . 7-31

Publication 1747-6.22

Switchover Considerations

Programming Techniques

Table of Contents

Directional Non-Continuous Block Transfer

Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-34

Bidirectional Continuous Block Transfer Example . 7-37

Bidirectional Alternating Block Transfer . . . . . . . . . 7-42

Bidirectional Alternating Repeating Block Transfer 7-48

Chapter 8

Timing Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1

Input Signal Update Time . . . . . . . . . . . . . . . . . . . . . . . 8-2

Time-out on Remote I/O Link . . . . . . . . . . . . . . . . . . . . 8-2

Data Table Transfer Time on HSSL . . . . . . . . . . . . . . . 8-2

Divergence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

Forcing I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

Data Highway Plus Switching . . . . . . . . . . . . . . . . . . . . . . 8-4

Remote I/O Switching . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6

Chapter 9

Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1

Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1

Program File 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-2

Program File 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3

Program File 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-8

Data Transfer Schemes . . . . . . . . . . . . . . . . . . . . . . . . . . 9-13

Data Transfer Method 1. . . . . . . . . . . . . . . . . . . . . . . . 9-13

Data Transfer Method 2. . . . . . . . . . . . . . . . . . . . . . . . 9-14

Other transfer methods . . . . . . . . . . . . . . . . . . . . . . . . 9-15

Accounting for Instructions That Could Cause

Problems During Switchover . . . . . . . . . . . . . . . . . . . . . 9-16

Timer Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-16

Counter Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . 9-17

Programming Techniques . . . . . . . . . . . . . . . . . . . . . . 9-18

Diagnostic, Sequencing, File Arithmetic and Logic

File Search and Compare, File Copy

and Fill Instructions. . . . . . . . . . . . . . . . . . . . . . . . . 9-18

FIFO and Bit Displacement Instructions . . . . . . . . . . . 9-18

Block Transfer Instructions . . . . . . . . . . . . . . . . . . . . . 9-19

Message Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . 9-19

PID Control Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-20

Summary of Programming Considerations . . . . . . . . . . . 9-20

Publication 1747-6.22

Table of Contents

Specifications

M0-M1 Files and G Files

Appendix A

Backup Scanner Operating Specifications . . . . . . . . . . . . .A-1

Network Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1

Throughput Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . .A-2

RIO Network Throughput Components . . . . . . . . . . . . .A-2

Calculating Throughput . . . . . . . . . . . . . . . . . . . . . . . . . . .A-3

Discrete I/O Throughput without Block Transfers

(Tdm-nbt) Present . . . . . . . . . . . . . . . . . . . . . . . . . . .A-3

RIO Scan Time Calculation (TRIO) . . . . . . . . . . . . . . . .A-4

Example Discrete I/O Throughput without Block

Transfers Present. . . . . . . . . . . . . . . . . . . . . . . . . . . .A-4

Discrete I/O Throughput with Block Transfers

(Tdm-bt) Present . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-6

Determining TSNo-bt . . . . . . . . . . . . . . . . . . . . . . . .A-6

Determining Tbtx . . . . . . . . . . . . . . . . . . . . . . . . . . .A-7

Example Discrete I/O Throughput with Block Transfers

Present. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-7

Block Transfer Throughput. . . . . . . . . . . . . . . . . . . . . . .A-9

Backup Scanner Output Delay Time (TSNo) Tables . .A-11

Determining the Number of Logical Racks

Configured . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-11

Appendix B

M0-M1 Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-1

Configuring M0-M1 Files . . . . . . . . . . . . . . . . . . . . . . . .B-1

Addressing M0-M1 Files . . . . . . . . . . . . . . . . . . . . . . . .B-2

Using M0-M1 Data File Addresses . . . . . . . . . . . . . . . .B-2

Monitoring Bit Addresses . . . . . . . . . . . . . . . . . . . . . . . .B-3

M0/M1 Monitoring Option Disabled . . . . . . . . . . . . . . . .B-3

M0/M1 Monitoring Option Enabled. . . . . . . . . . . . . . . . .B-4

Transferring Data Between Processor Files

and M0 or M1 Files . . . . . . . . . . . . . . . . . . . . . . . . . .B-4

Access Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-5

SLC 5/02 Processor Example. . . . . . . . . . . . . . . . . .B-5

SLC 5/03 Processor Example. . . . . . . . . . . . . . . . . .B-6

SLC 5/04 Processor Example. . . . . . . . . . . . . . . . . .B-6

Minimizing the Scan Time . . . . . . . . . . . . . . . . . . . . . . .B-6

Capturing M0-M1 File Data . . . . . . . . . . . . . . . . . . . . . .B-7

Specialty I/O Modules with Retentive Memory. . . . . . . .B-8

G Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-8

Configuring G Files . . . . . . . . . . . . . . . . . . . . . . . . . .B-9

Editing G File Data . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-10

Publication 1747-6.22

Glossary

Index

Table of Contents

Appendix C

RIO Configuration Worksheet . . . . . . . . . . . . . . . . . . . . C-1

Directions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1

Publication 1747-6.22

xii

Table of Contents

Publication 1747-6.22

Preface

Read this preface to familiarize yourself with the rest of the manual.

This preface covers the following topics:

• who should use this manual

• how to use this manual

• related publications

• conventions used in this manual

• Allen-Bradley support

Who Should Use This

Manual

Use this manual if you are responsible for designing, installing, programming, or troubleshooting control systems that use

Allen-Bradley small logic controllers.

How to Use This

Manual

As much as possible, we organized this manual to explain, in a taskby-task manner, how to install, configure, program, operate and troubleshoot a control system using the 1747-BSN Backup Scanner.

Manual Contents

If you want...

An overview of the system including backup scanner/SLC interaction, compatible devices, and features

A quick start guide for experienced users

Installation and wiring guidelines

Operating your SLC 500 backup system

Backup scanner configuration information, I/O file information, and G and M file descriptions

Information on module control and status word

RIO block transfer information, M file block transfer buffer layout, block transfer examples

Switchover considerations

Programming techniques

Backup scanner and system specifications

Information and usage of M and G files

Worksheets for configuring the scanner’s I/O image

Definitions of terms used in this manual

See

Chapter 1

Chapter 2

Chapter 3

Chapter 4

Chapter 5

Chapter 6

Chapter 7

Chapter 8

Chapter 9

Appendix A

Appendix B

Appendix C

Glossary

Publication 1747-6.22

Conventions Used in

This Manual

The following conventions are used throughout this manual:

• Bulleted lists (like this one) provide information not procedural steps.

• Numbered lists provide sequential steps or hierarchical information.

• Italic type is used for emphasis.

• Text in this font

indicates words or phrases you should type.

Allen-Bradley Support

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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.

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Troubleshooting first. Then call your local Allen-Bradley representative.

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

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Control and Information Group

Technical Communication, Dept. A602V, T122

P.O. Box 2086

Milwaukee, WI 53201-2086

Publication 1747-6.22

System Overview

Chapter

Overview

This chapter contains the following information:

• system overview

• how the scanner interacts with the SLC processor

• how the scanner interacts with adapter modules

• scanner I/O image concepts

• extended node capability

• complementary I/O

• scanner features

• compatible network devices

• backup concepts for the SLC-500 system

The 1747-BSN Backup Scanner provides redundancy for:

• Remote I/O (RIO)

• RS232 channel switchover for communications to devices such as operator interface

• DH+

The backup scanner also provides a High Speed Serial Link (HSSL) to write any retentative data from a primary to a secondary processor.

In addition, the module has a Local Serial Link (LSL) to pass status information between multiple BSN modules located in the same chassis (optional).

The 1747-BSN is a complementary set of modules, with one module residing in the primary system and another module in the secondary or backup system. The primary module controls the operation of remote I/O, while the secondary module is available to take over control in the event of a fault in the primary.

The backup scanner has the capability to switch between two communication channels. The first channel is configurable as RIO or

DH+. The second channel is used to switch the RS232/485 channel in order to provide connection for electronic operator interfaces.

The Remote I/O (RIO) scanner, Catalog Number 1747-SN, is the remote I/O scanner for the SLC 500. It enables communication between an SLC processor (SLC 5/02 or later) and remotely located

(3,048 meters [10,000 feet] maximum) 1746 I/O chassis and other

RIO-compatible Allen-Bradley operator interface and control devices. The 1747-SN scanner communicates with remotely located devices using the A-B Remote I/O link. The RIO link consists of a single master (scanner) and multiple slaves (adapters).

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Overview

Communication between devices occurs over twisted-pair cable with the devices daisy-chained together. The scanner can reside in any slot of the local SLC chassis except for slot 0. The 1747-BSN includes the same functionality as the 1747-SN scanner, as well as the backup features.

SLC 5/02 or later Processor

RIO Scanner (Master of the RIO LInk)

Local SLC Chassis

The scanner transfers input and output data between itself and all configured network devices over twisted-pair cable. Note that the end-to-end length of the cable can be a maximum of 3,048 meters (10,000 feet)

1747-ASB Module (Adapter/

Slave)

Remote Chassis

Remote Expansion Chassis

Dataliner Message Display

(Adapter/Slave)

PanelView-Operator Terminal

(Adapter/Slave)

RediPANEL-

(Adapter/Slave)

The scanner can be configured for and transfer a maximum of 4 logical racks of discrete data on the RIO link. The scanner provides discrete I/O and block transfers. Configurations allowed are any combination of quarter, half, three quarter, or full logical rack devices.

SLC 5/02 or

Later Processor RIO Scanner

The scanner transfers discrete input and output data between itself, remote adapters, and the SLC processor. Remote adapters consist of

1746 chassis and other Allen-Bradley operator interface and control devices.

Adapter 1

Half Logical

Rack

Device

Adapter 2

Quarter Logical

Rack

Device

Adapter 3

Half

Logical Rack

Device

Adapter 4

Three Quarter

Logical Rack Device

Adapter 5

Full

Logical Rack

Device

Adapter 6

Full

Logical Rack

Device

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Overview

1-19

The SLC processor transfers the scanner’s 4 logical racks (32 input image and 32 output image words) of discrete remote I/O image data into the SLC input and output image files. You can adjust the size of the scanner input and output image file during configuration of your

SLC system so that the scanner only transfers the discrete I/O data your application program requires. Configuration is done through the configuration file (G file). Refer to chapter 4, Configuration and

Programming, for more information.

Important: The SLC 500 processor (SLC 5/02 or later) supports multiple scanners in its local I/O chassis. The maximum number is dependent on the following:

• backplane power requirements (power supply dependent)

• SLC 500 processor I/O data table limit (4,096 I/O)

Based on SLC processor I/O capacity only, a maximum of eight scanners may be used when no local I/O exists.

• processor memory to support the application (SLC 500 processor dependent)

Scanner I/O Image Division

The scanner allows each adapter to use a fixed amount (user-defined) of the scanner’s input and output image. Part of the SLC processor’s image is used by local I/O; the other portion is used by the scanner for remote I/O.

The scanner remote I/O 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.

Local I/O

Logical Rack 0

Remote I/O

Logical Rack 1

Logical Rack 2

Logical Group 0

Logical Group 7

Scanner I/O Image

Processor I/O Image

Adapter

Image

The scanner image 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.

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Overview

How the Scanner

Scans Remote I/O

The scanner communicates with each logical device in a sequential fashion. First, the scanner initiates communication with a device by sending output data to the device. The device then responds by sending its input data back to the scanner, as illustrated below. You refer to this exchange as a discrete I/O transfer. After the scanner completes its discrete I/O transfer with the last configured network device, it begins another discrete I/O transfer with the first device.

It is important to understand that the scanner transfers RIO data on a logical device basis not on an adapter basis. A logical device is a full logical rack or portion of a logical rack assigned to an adapter.

RIO Scanner Scan

The scanner updates its input image file each time it scans a logical device.

Scanner Input

Image File

Output Device

Input

Device 1

Input Device

Output Device

Input Device

Output

Device 2

Scanner Output Image

File

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Overview

1-21

SLC and Scanner

Asynchronous

Operation

The SLC processor scan and RIO scanner scan are independent

(asynchronous) of each other. The SLC processor reads the scanner input image file during its input scan and writes the output image file to the scanner during its output scan. The RIO scanner continues reading inputs and writing outputs to the scanner I/O image file, independent of the SLC processor scan cycle.

Depending on your SLC processor, RIO link configuration, and application program size, the scanner may complete multiple scans before the SLC processor reads the scanner’s input image file. The

RIO scanner updates its I/O files on a per logical rack basis.

The figure below illustrates the asynchronous operation of the SLC processor and RIO scanner.

SLC Processor Scan Cycle

The SLC processor reads the scanner input image file into the

SLC input image file, processes it, and creates an SLC output image file. The SLC processor transfers its output file to the scanner.

Progra m

SLC Input

Image File

SLC Processor

SLC Output

Image file

Scanner

Input

Image File

Output

Image

Device 3

I nput

Image

Device 3

Output

Image

Device 2

Input

Image

Device 1

Output

Image

Device 1

Input

Image

Device 2

Scanner

Output Image

File

RIO Scanner Scan Cycle

The scanner updates its input image file each time it scans a logical device. The scanner may scan all of its configured logical devices several times before the SLC processor reads the scanner’s input image file

Important: The outputs of the RIO are updated after the end of the first SLC processor scan.

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1-22

Overview

How the Scanner

Interacts with

Adapters

SLC Local Chassis

Processor

Scanner

The scanner’s function is to continuously scan the adapters on the

RIO link in a consecutive manner. This scan consists of one or more

RIO discrete transfers to each adapter on the RIO link.

RIO discrete transfers consist of the scanner sending output image data and communication commands to the adapter that instruct the adapter on how to control its output. (These include run, adapter reset, and reset decide commands.) The adapter responds by sending input data to the scanner. The scanner performs as many RIO discrete transfers as necessary to update the entire adapter image. If RIO discrete transfers do not occur, data is not exchanged between the scanner and adapter. RIO discrete transfers are asynchronous to the processor scan.

RIO Discrete

Transfers with

Adapter 1

RIO Discrete

Transfers with Adapter 2

PanelView Operator Terminal

RIO Discrete Transfers with Adapter 3

RIO Discrete

Transfers with Adapter 4

RediPANEL

Scanner I/O Image Concepts

The scanner’s I/O image consists of RIO logical racks and I/O groups. A full RIO logical rack consists of eight input image and eight output image words. (A word consists of 16 bits of data.) Each word within an RIO logical rack is assigned an I/O group number from 0 to 7.

You assign devices on the RIO link a portion of the scanner’s image.

Devices can occupy a quarter logical rack (2 input and output words), half logical rack (4 I/O words), three quarter logical rack (6 I/O words), or full logical rack. You may configure devices to start at any even I/O group number within an RIO logical rack. More than one physical device’s (adapter) I/O information can reside in a single logical rack. Also, by crossing logical rack boundaries a device can consist of more than one logical rack.

Important: The illustration below shows only the input image configuration of the scanner’s I/O image. The output image configuration is the same.

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Overview

1-23

Input Image Half of a Scanner’s I/O Image

RIO

Logical

Rack 0

RIO

Logical

Rack 1

RIO

Logical

Rack 2

RIO

Logical

Rack 3

Bit Number (decimal)

Rack 0 Group 0

Word 0

Rack 0 Group 1 Word 1

Rack 0 Group 2 Word 2

Rack 0 Group 3 Word 3

Rack 0 Group 4 Word 4

Rack 0 Group 5 Word 5

Rack 0 Group 6 Word 6

Rack 0 Group 7 Word 7

Rack 1 Group 0 Word 8

Rack 1 Group 1 Word 9

Rack 1 Group 2 Word 10

Rack 1 Group 3 Word 11

Rack 1 Group 4 Word 12

Rack 1 Group 5 Word 13

Rack 1 Group 6 Word 14

Rack 1 Group 7 Word 15

Rack 2 Group 0 Word 16

Rack 2 Group 1 Word 17

Rack 2 Group 2 Word 18

Rack 2 Group 3 Word 19

Rack 2 Group 4 Word 20

Rack 2 Group 5 Word 21

Rack 2 Group 6 Word 22

Rack 2 Group 7 Word 23

Rack 3 Group 0 Word 24

15 14

Bit Number (octal)

13 12 11 10

9 8 7

5 4 3 2 1

Quarter Logical

Rack

Not Used In This

Example

Half Logical

Rack

Not Used In This

Example

Three Quarter

Logical Rack

Not Used In This

Example

Full Logical

Rack

SLC 5/02 or

Later

Processor

RIO

Scanner

Example Scanner I/O Image

The illustrations below show a scanner’s input image of 4 RIO link devices.

Device 1

Full Logical Rack

Device

Begins at Logical Rack

0, Group 0

Device 2

Device 3

Three Quarter Logical Rack

Device

Begins at Logical Rack 1,

Group 0

Half Logical Rack

Device

Begins at Logical Rack

2, Group 0

Device 4

Quarter Logical Rack

Device

Begins at Logical Rack 2,

Group 4

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1-24

Overview

Important: The illustration below shows only the scanner’s input image. The output image looks the same.

RIO

Logical

Rack 0

RIO

Logical

Rack 1

RIO

Logical

Rack 2

RIO

Logical

Rack 3

Bit Number

Rack 0 Group 0 Word 0

Rack 0 Group 1 Word 1

Rack 0 Group 2 Word 2

Rack 0 Group 3 Word 3

Rack 0 Group 4 Word 4

Rack 0 Group 5 Word 5

Rack 0 Group 6 Word 6

Rack 0 Group 7 Word 7

Rack 1 Group 0 Word 8

Rack 1 Group 1 Word 9

Rack 1 Group 2 Word 10

Rack 1 Group 3 Word 11

Rack 1 Group 4 Word 12

Rack 1 Group 5 Word 13

Rack 1 Group 6 Word 14

Rack 1 Group 7 Word 15

Rack 2 Group 0 Word 16

Rack 2 Group 1 Word 17

Rack 2 Group 2 Word 18

Rack 2 Group 3 Word 19

Rack 2 Group 4 Word 20

Rack 2 Group 5 Word 21

Rack 2 Group 6 Word 22

Rack 2 Group 7 Word 23

Bit Number (octal)

13 12 11 10 9 8

6 5 4 3 2 1

I:e.6

I:e.7

I:e.8

I:e.9

I:e.10

I:e.11

I:e.12

I:e.13

Input File

Address

I:e.0

I:e.1

I:e.2

I:e.3

I:e.4

I:e.5

I:e.14

I:e.15

I:e.16

I:e.17

I:e.18

I:e.19

I:e.20

I:e.21

I:e.22

I:e.23

Device 1

Device 2

Not Used

Device 3

Device 4

Not Used

8 e = slot number of the SLC chassis containing the scanner

Transferring Data with RIO Discrete and Block Transfers

Input and output image data and command information are quickly exchanged between a scanner and adapter using RIO discrete transfers. RIO discrete transfers are the simplest and fastest way a scanner and adapter communicate with each other. RIO discrete transfers, which are transparent to the user, consist of the scanner sending the output image data to the adapter, and the adapter transmitting input data to the scanner. Each RIO discrete transfer also contains scanner commands for the adapter.

Through your control program you command the SLC processor to initiate RIO block transfers, which directs the scanner to exchange large amounts of data to/from an adapter. Block Transfers (BTs) use the basic RIO discrete transfer mechanism of the RIO link. However, the actual transfer of data occurs asynchronous to the discrete transfers. It is possible for several discrete transfers to occur before the scanner processes a block transfer. Refer to chapter 5, RIO Block

Transfer for more details.

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Overview

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Physical and Logical RIO Link Specifications

The maximum number of adapters with which your scanner can communicate is determined by the scanner’s and adapter’s physical and logical specifications, as described below:

• Physical Specifications are the maximum number of adapters that can be connected to the scanner. For more information, see

Extended Node Capability below.

• Logical Specifications for the scanner are the maximum number of logical racks the scanner can address, how the logical racks can be assigned, and whether the scanner can perform block transfers.

Extended Node Capability

Extended node functionality allows you to connect up to 32 physical devices on an RIO link. You must use 82 Ohm termination resistors in an extended node configuration. You can only use extended node if

all RIO link devices have extended node capability. (Refer to the

Compatible Devices table at the end of this chapter, or to the specifications of your device.) The 1747-BSN Scanner has extended node capability. However, the smallest logical rack division is 1/4 logical rack and the scanner image size is 4 logical racks. Therefore, the scanner is limited to 16 devices unless complementary I/O is used.

Refer to the following section for more information on complementary I/O.

Complementary I/O

Complementary I/O is very useful when portions of your input and output images are unused because it allows the images of two adapters to overlap each other in the scanner’s I/O image. To use complementary I/O, the I/O image from one adapter must be the mirror (complement) of the other. This means that if there is an input module in the primary chassis, there must be an output module in the same slot of the complementary chassis. This enables total use of the scanner’s 32 input and 32 output word image for I/O addressing of up to 1024 discrete points.

ATTENTION: Because the primary and complementary chassis images overlap, input and specialty combination I/O modules must never share the same image location. Inputs received by the scanner may be incorrect and RIO block transfers will not be serviced properly.

If an output module shares its output image with another output module, both output modules receive the same output information.

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Overview

If you want to use complementary I/O, two adapters that support this function are required (e.g., 1747-ASB modules). One adapter is configured (via its DIP switches) as a primary chassis, the other as a complementary chassis. If a primary chassis exists, it is scanned first.

Primary and complementary chassis cannot have the same logical rack number. The logical rack numbers must be assigned to the primary and complementary racks as shown below:

Primary Chassis

Logical Rack Number

Complementary Chassis Logical Rack Number

Decimal Octal

ATTENTION: If the logical rack numbers are not properly assigned, unpredictable operation of both ASB modules results. No ASB module errors occur. Refer to your ASB module user manual for specific information on setting the address of the complementary chassis.

(For example, in the 1771-ASB manual the addresses for the complementary chassis are referred to as complementary chassis 0-3.)

Guidelines for Configuring Complementary I/O

When you configure your remote system for complementary I/O, follow these guidelines:

• You can place an output module in the primary chassis opposite another output module in the complementary chassis; they use the same bits in the output image table. However, we do not recommend this placement of modules for redundant I/O.

• You cannot use complementary I/O with a chassis that uses

32-point I/O modules and 1-slot addressing or 16-point I/O modules with 2-slot addressing.

• Do not place an input module in the primary chassis opposite an input module in the complementary chassis because they use the same bits in the input image table.

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Overview

1-27

Complementary I/O: Placing Modules with 2-Slot Addressing

The figures below illustrate a possible module placement to configure complementary I/O using 2-slot addressing.

0 1

3 4 5

1 2

0 1 2 3 4 5

Outputs in the complementary chassis would use the same bits in the output image table as the outputs in the primary chassis. You cannot place inputs in the complementary chassis.

1 = Output modules use the same output image table bits. This is not recommended.

2 = Must be empty if corresponding primary slot is a block transfer module.

Important: With 2-slot addressing, if an input module resides in either slot, associated with a logical group, of the primary chassis, an input module cannot reside in that logical group’s complementary chassis.

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Overview

Complementary I/O: Placing Modules with 1-Slot Addressing

The figure below illustrates a possible module placement to configure complementary I/O using 1-slot addressing.

BT I

1 2 3 4 5 6 7 0 1 2 3

0 1 2 3 4 5 6 7 0 1 2 3

I = Input Module (8- or 16-point) O = Output Module (8- or 16-point)

BT = Block Transfer Module

1 = Output modules use the same output image table bits. This is not recommended.

2 = Must be empty if corresponding primary slot is block transfer.

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Complementary I/O: Placing Modules with 1/2-Slot Addressing

The figure below illustrates a possible module placement to configure complementary I/O using 1/2-slot addressing.

I I O O I O O BT O

01 23 45 67 01 23 45 67 01 23

O I I O I O

1 2

I O

I I I I I I I I I I

01 23 45 67 01 23 45 67 01 23

O O O O O O O O O O

I = Input Module (8-, 16-, or 32-point) O = Output Module (8-, 16-, or

32-point) BT = Block Transfer Module

1 = Output modules use the same output image table bits. This is not recommended.

2 = Must be empty if corresponding primary slot is block transfer.

Summary for Placing Modules Used In Complementary I/O

Discrete Modules

Addressing Method

2-slot

Types of Modules used

8-point

Placement

Install input modules opposite output modules, and output modules opposite input modules.

1-slot

1/2-slot

8-point, 16-point

8-point, 16-point, 32-point

1. If an input module resides in either slot, associated with a logical group, of the primary chassis, an input module cannot reside in that logical group’s complimentary chassis.

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Overview

Block Transfer Modules

Addressing Method

2-slot

Placement

The right slot of the primary I/O group can be another block transfer module, or an 8-point input or output module.

The left slot of the complementary I/O group must be empty.

In the right slot of the complementary I/O group, you can place an 8-point output module; this slot must be empty if the corresponding slot in the primary I/O group is a block transfer module.

1-slot

1/2-slot

Leave the corresponding I/O group in the complementary chassis empty.

The following example illustrates how I/O modules requiring two words of the input or output image can leave unused image space.

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Overview

1-31

O O

I = Input Module

O= Output Module

0 1 2 3 4 5 6 7 8

Slot Pair

1 2 3 4 Slot Pair

0 1 2 3 4 5 6 7 8

1 2 3 4

Primary Chassis

Primary Chassis Configured As:

Logical Rack Number

Logical Group Number

Image size (logical groups)

Addressing Mode

Primary/Complementary

1/2 -slot

Primary

Complementary Chassis

Complementary Chassis Configured

As:

Logical Rack Number

Logical Group Number

Image Size (logical groups)

Addressing Mode

Primary/Complementary

8 (decimal)

1/2-slot

Complementary

Primary Chassis I/O Image

Input Image Output Image from Primary Chassis from Primary Chassis

Slot 4

Slot 5

Slot 6

Slot 7

Slot 8

Slot 1

Slot 2

Slot 3

Slot 4

Slot 5

Slot 6

Slot 7

Slot 8

Slot 1

Slot 2

Slot 3

Slot 4

Octal

Decimal

Slot Pair

Slot 4

Slot 5

Slot 6

Slot 7

Slot 8

Slot 1

Slot 2

Slot 3

Slot 4

Slot 5

Slot 6

Slot 7

Slot 8

Slot 1

Slot 2

Slot 3

Slot 4

Octal

Decimal

Slot Pair

Complementary Chassis I/O Image

Input Image from Complementary Chassis

Output Image from Complementary Chassis

Slot 4

Slot 5

Slot 6

Slot 7

Slot 8

Slot 1

Slot 2

Slot 3

Slot 4

Slot 5

Slot 6

Slot 7

Slot 8

Slot 1

Slot 2

Slot 3

Slot 4

Octal

Decimal

Slot Pair

Slot 4

Slot 5

Slot 6

Slot 7

Slot 8

Slot 1

Slot 2

Slot 3

Slot 4

Slot 5

Slot 6

Slot 7

Slot 8

Slot 1

Slot 2

Slot 3

Slot 4

Octal

Decimal

Slot Pair

= unused image space

Scanner’s I/O Image

Both images are overlapped in the scanner. The overlapped image appears where the primary chassis image is configured to reside.

Group 0

Group 1

Group 2

Group 3

In this case, the primary chassis image is configured as starting logical rack 0 and starting logical group 0.

Logical

Group 4

Rack 0

Group 5

Group 6

Group 7

Group 0

Group 1

Group 2

Group 3

Logical

Rack 1

Group 4

Group 5

Group 6

Group 7

Input Image Output Image

Slot 1

Slot 2

Slot 3

Slot 4

Slot 5

Slot 6

Slot 7

Slot 8

Slot 1

Slot 2

Slot 3

Slot 4

Slot 5

Slot 6

Slot 7

Slot 8

Octal

Decimal

Slot Pair

Slot 1

Slot 2

Slot 3

Slot 4

Slot 5

Slot 6

Slot 7

Slot 8

Slot 1

Slot 2

Slot 3

Slot 4

Slot 5

Slot 6

Slot 7

Slot 8

Octal

Decimal

Slot Pair

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Overview

Logical

Rack 0

Word 0

Word 1

Word 2

Word 3

Word 4

Word 5

Word 6

Word 7

Complementary I/O Application Considerations

If you configure a complementary device to use more I/O image space than an associated primary device, then block transfers can only be performed to locations in the complementary device that have associated I/O image space in the primary device. For example, if a primary device is 1/2 logical rack and a complementary device is a full logical rack, block transfers can be performed only in the first 1/2 logical rack of the complementary device. Attempting block transfers in the last half of the complementary device results in a BT error

(error 11 - device not configured).

1/2 logical rack configured and usable

1/2 logical rack not configured

Logical

Rack 8

Word 0

Word1

Word 2

Word 3

Word 4

Word 5

Word 6

Word 7

1/2 logical rack configured and usable

1/2 logical rack configure but not usable for BT sin

Words 4-7 are not configured for the primar device.

Complementary 1771 I/O Module Details

Use the following modules in either primary or complementary I/O chassis opposite any type of module:

• Communication Adapter Module (1771-KA2)

• Communication Controller Module (1771-KE)

• PLC-2 Family/RS-232-C Interface Module (1771-KG)

• Fiber Optics Converter Module (1771-AF)

• DH/DH+ Communication Adapter Module (1785-KA)

• DH+/RS-232C Communications Interface Module (1785-KE)

Use the following modules in either primary or complementary I/O chassis opposite any type of module. However, these modules do not work as standalone modules; each one has an associated master module. Use care when placing the master modules in the I/O chassis:

• Analog Input Expander Module (1771-E1, -E2, -E3)

• Analog Output Expander Module (1771-E4)

• Servo (Encoder Feedback) Expander Module (1771-ES)

• Pulse Output Expander Module (1771-OJ)

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Overview

Hardware Features

Note the backup scanner’s hardware features in the following illustration.

BACKUP SCANNER

PRI SEC

ERR

FLT

RIO

HSSL

Status LEDs

High-Speed Serial Link (HSSL)

Local Status

Link (LSL)

1-33

Status LEDs

The table below describes the six LEDs located on the module’s front panel. To ensure that they are operating correctly, all LEDs are illuminated during power up.

LED

PRI

SEC

RIO

ERR

HSSL

FLT

Definition

Primary

Secondary

RIO Communication

Backup Module Error

High-Speed Serial

Link Communication

Fault

Status & Color

Steady Green

Steady Amber

Steady Green

Flashing Green

Flashing Red

Steady Red

Off

Flashing Red

Off

Flashing Green

Off

Steady Red

Flashing Red

Indication

The module is in the primary mode.

The module is in the secondary mode.

The RIO link is working properly.

A remote device is not configured or connected correctly, or is faulted.

The RIO link has a fault. The scanner is connected incorrectly, or all devices are configured improperly, have no power, or are faulted.

There is a configuration error.

The communication channel is not configured as RIO.

The module is not ready for switchover.

The module is ready for switchover.

The link is operating with no errors.

A communications error has been detected on the HSSL.

A hardware fault has occurred.

The module is not configured properly.

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Overview

Configuration Switch

Module Address Switch

1 2 3 4 5 6 1 2 3 4

1 2 3 4 5 6

1 2 3 4

Configuration Dip Switch Settings

The six-position Configuration DIP Switch is used to select the baud rate, configure the communication channel and identify each individual BSN module and the last BSN module. The tables below define the DIP switch configuration settings.

DIP Switch

Position

1 and 2

Definition Setting

Set the communication channel baud rate

Channel configuration

See the table below

DH+ = ON

RIO = OFF

This user identification switch differentiates between BSN modules in the primary system and

BSN modules in the secondary system, helping determine if switchover has occurred. This switch is user-configurable and will not affect the operation of the module.

Reserved

Identifies the last module in the local status link, if multiple BSN modules are used in each chassis. If only one module is used in each chassis, turn this switch to ON.

User selectable

Last module = ON

All others = OFF

Baud Rate Settings

Position 1

OFF

Position 2

OFF

Baud Rate

57.6K

115.2K

230.4K

Disabled

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Module Address Switch

The four-position Module Address DIP switch configures the BSN address in the LSL. The following table shows the address that corresponds to each setting.

OFF

Switch Position

OFF

1747-BSN Address

Note:

Switch position 4 is not used.

Compatible Devices

The 1747-BSN is compatible with all Remote I/O adapter devices.

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Overview

Backup Concepts for the SLC 500 System

Why Use a Backup System?

The objective of any redundant system (backup system) is to improve the amount of up-time of a machine or process by ensuring consistent availability of that machine, and by reducing costs associated with equipment failure. By using this backup system, you can guard your application against shutdowns caused by the programmable controller.

ATTENTION: Backup does not protect you from faults caused by programming errors or system timeouts because such an error or timeout also occurs in the secondary processor.

The backup option is used where you must transfer the control of the process to a secondary system, without thereby interrupting the machine/process operation.

To guard against system shutdown, a backup system must provide:

• equipment with exceptional reliability

• automatic fault isolation

• minimal disturbance of the process when switching from the primary to the secondary system

Applying 1747-BSN Backup Scanner Modules to the SLC-500

Programmable Controller

A SLC 500 system configured with 1747-BSN modules provides high-speed backup communication and switchover of the Data

Highway Plus, remote I/O links, and RS232 channel (on 5/03 and later processors). In this section we:

• show a typical SLC 500 backup configuration

• explain how the backup system works

• describe the role of the 1747-BSN module

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Overview

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A Typical SLC 500 Backup Configuration

A SLC 500 backup system contains a minimum of two each of the following hardware components:

• SLC 500 processor module

Processor: * Catalog Number:

SLC 5/02 1747-L524

SLC 5/03 1747-L531, -L532

SLC 5/04 1747-L541, -L542, -L543

SLC 5/05 1747-L551, -L552, -L553

Contact your Allen-Bradley Sales Office or your Allen-Bradley distributor for additional SLC 500 processors that can be configured with the 1747-BSN modules.

• 1747-BSN module

• power supply

• local chassis

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Overview

How the SLC 500 Backup System Works

In the SLC 500 backup configuration, one system (consisting of one

SLC 500 processor, 1747-BSN module, power supply, and chassis) controls the operation of the remote I/O. This system is referred to as the primary system. The other system is ready to take control of the remote I/O in the event of a fault in the primary system. This is referred to as the secondary system. The SLC 500 backup system does not back up local I/O; therefore, do not install I/O in the local chassis.

The system provides high-speed data table transfer from the primary

system to the secondary system. This guarantees that the data tables of the two processors track each other. To provide the possibility of backing up a large number of I/O points, a backup system supports up to eight 1747-BSN modules in each processor chassis linked by a local status link (LSL).

The high-speed serial link (HSSL) has the following functionality:

• Send the network commands from the primary to the secondary

1747-BSN and the replies from the secondary to the primary when the communication channel is configured as DH+.

• Transfer a limited number of SLC 5/0x data table files from primary to the secondary processor. This data table transfer is done through an application program in the SLC 5/0x processor.

Although data transfer between the primary and secondary processors is done as fast as possible, there is no guarantee that a switchover from the primary to the secondary will be bumpless. The data rate is 2

Mbits/second.

The local status link (abbreviated LSL) is a 57.6 KBaud serial link provided for exchanging status between the 1747-BSNs that are in the same chassis.

Data Transfer

During normal operation, the primary system sends remote input and retentative data table data to the secondary system so that in the event of a switchover, the secondary system (which becomes the new primary system) has the same data.

Remote I/O data is automatically transferred over the High-Speed

Serial Link. This transfer is independent of the application program.

Each 1747-BSN is capable of transferring up to 2 KWord of the SLC

500 data table. This capacity is increased as the number of 1747-BSN modules per local chassis is increased in a redundant system. For example, a system with eight 1747-BSNs in each chassis is capable of transferring up to 16 KWord of synchronizing data table information.

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Overview

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Data table values are transferred from the primary to the secondary system with M0 and M1 files and the HSSL. You copy the data to and from M files via your ladder program.

You do not have to transfer data table values if not necessary for your application.

For detailed information about data transfer from the primary to the secondary system, refer to Chapter 5, “Operating Your SLC 500

Backup System”.

Switchover

Should a fault occur in the primary processor, control switches to the secondary system in less than 50 ms (maximum). When a switchover occurs, the outputs in the remote I/O maintain their last state until they come under the control of the secondary processor.

The program scans of the two processors are not synchronized. This means that the secondary processor may be in a different place in the scan cycle than the primary processor. This manual explains the switchover process and provides guidelines for developing programs for your SLC 500 backup system. (For more information about switchover, refer to “Switchover Considerations” on page 8-1.)

Role of the 1747-BSN Module

As an integral part of the backup system, the 1747-BSN modules enable high-speed communication between the two SLC processors and permit the secondary processor to assume control of the process.

In addition, the 1747-BSN module provides:

• high-speed transfer of the data table values from the primary to the secondary system (HSSL), to ensure that the secondary system’s data table is a copy of the primary system’s (2K words maximum per BSN module pair)

• exchange of information on the status of the primary and secondary systems (LSL)

• automatic transfer to the secondary system of the remote input

(discretes and analog values, etc.)

• transfer of control from the primary processor to the secondary processor when one of the following conditions occur:

— power failure or power loss

— major processor fault

— 1747-BSN module fault, including communications timeout in the RIO link

— change in the primary processor’s mode from:

• RUN to PROGRAM (manual switchover)

• REM RUN to REM PROG

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Overview

• REM RUN to REM TEST

• transfer of control from the primary processor to the secondary when one of the following conditions is detected by the secondary processor:

— communication timeout in the HSSL between the two

1747-BSN modules and primary system is not updating the remote I/O

— transfer of control command from the primary 1747-BSN module

• substitution of equipment without interruption of the process; that is, the faulted system can be repaired while the other system is controlling the process

• connections for remote I/O and Data Highway Plus network (the

1747-BSN module routes the remote I/O network and the Data

Highway Plus network to the primary processor)

• isolation of the systems, in order to guarantee that a fault in one system does not affect the other

• diagnostics information

• remote programming capability for secondary processor. The secondary processor is in the DH+ network

• the capability of switching two communication channels (one configurable as RIO or DH+ and one RS-232/485 for DH485)

• minimal user programming impact

• use of standard SLC 5/02 or later and 1746 platform (no need for special chassis or processor)

• no added cost if you are not using backup

Publication 1747-6.22

Required Tools and

Equipment

Chapter

Quick Start for Experienced Users

This chapter helps you to get started using the Backup Scanner. 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.

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

• programming equipment

• termination kit (package of resistors and ring lug included with the scanner)

• approximately 15 inches of #20 AWG for grounding the drain shield to the SLC chassis (for Series A retrofits)

• an adequate length of RIO communication cable (Belden 9463) for your specific application

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Quick Start for Experienced Users

Procedures

1. Ensure your chassis supports placement of the 1747-BSN module.

Review the power requirements of your system to see that your chassis supports placement of the scanner module. The scanner consumes 800 mA at 5V dc.

2. Configure the module using the DIP switches.

Set the DIP switches located on the printed circuit board.

The sixposition Configuration DIP Switch is used to select the baud rate, configure the communication channel, and identify each BSN module and the last BSN module.

Important:

Note that all RIO devices must be configured for the same baud rate.

Refer to Chapter 3, “Installation and Wiring” to configure the switches.

3. Insert the 1747-BSN module into the chassis.

ATTENTION: Never install, remove, or wire modules with power applied to the chassis or devices wired to the module.

Make sure system power is off; then insert the scanner module into your 1746 chassis.

In this example procedure, local slot 1 is selected.

Top and Bottom

Module Release

Card

Guide

4. Connect all RIO link devices.

Ensure that you:

• Daisy chain each RIO link device.

• Ground the shield drain wire to the nearest chassis mounting bolt.

• Connect the appropriate termination resistors on each end of the link.

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5. Configure the system.

Set up your system I/O configuration for the particular slot in which you installed the scanner (slot 1 in this example). If the 1747-BSN is not yet listed in your version of programming software, select

“Other” and type in a module ID code of 13608.

6. Enter the number of scanned words.

Enter the number of Scanned Input and Output Words using the

Specialty I/O and Advanced Setup menus. The default value is 32 I/O words. You can specify less than 32 and reduce the processor scan time by transferring only the part of the input and output image that your application requires. It is important that you do not set either of these values to 0. If you do, the scanner does not work correctly.

7. Set the M0-M1 and G file sizes.

Using the Specialty I/O Configuration menu, set the M1 and M0 file sizes to 32 words (48 words if using complementary I/O). 32 words is the minimum required for operation. If you do not set the M1 and M0 file sizes to at least 32 words, the programming device does not allow you to access the M files in the SLC control program. The maximum

M file sizes are 5547 words for complete capability. There is no penalty to set the M file lengths to this maximum.

Set the G file size to 3 (5 if using complementary I/O) using the

Specialty I/O Configuration menu.

Write your ladder code to address discrete I/O from the 32 input and output image words and the M files for control and status of the RIO network as well as block transfer and the HSSL, if needed. Refer to

Appendix B, “M0-M1 Files and G Files” on page B-1 before completing this selection.

8. Go through the system start-up procedure.

A. Apply power.

B. Download your program to the SLC.

C. Place the SLC in Run mode.

The backup scanner's FAULT and ERROR LEDs are off, the RIO

LED is green, the HSSL LED is blinking and the two PRI and SEC shows each processor Mode at this time. (This is the valid LED pattern when in Run mode or after a Run mode to Program mode transition.)

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Quick Start for Experienced Users

Publication 1747-6.22

Configuration

Selection

Chapter

Installation and Wiring

This chapter contains the information necessary to:

• select the baud rate

• configure the Backup Scanner

• insert the Backup Scanner into the SLC chassis

• wire the RIO and communication links

Compliance to European Union Directives

If this product has the CE mark it is approved for installation within the European Union and EEA regions. It has been designed and tested to meet the following directives.

EMC Directive

This product is tested to meet Council Directive 89/336/EEC

Electromagnetic Compatibility (EMC) and the following standards, in whole or in part, documented in a technical construction file:

• EN 50081-2

EMC - Generic Emission Standard, Part 2 - Industrial

Environment

• EN 50082-2

EMC - Generic Immunity Standard, Part 2 - Industrial

Environment

This product is intended for use in an industrial environment.

The six-position Configuration DIP Switch is used to select the baud rate, configure the communication channel, and identify each individual BSN module and the last BSN module. The tables below define the DIP switch configuration settings.

DIP Switch

Position

1 and 2

Definition Setting

Set the communication channel baud rate.

Channel configuration.

This user identification switch differentiates between

BSN modules in the primary system and BSN modules in the secondary system, helping determine if switchover has occurred.

Reserved.

Identifies the last module in the local status link.

See the table on page 2

DH+ = ON

RIO = OFF

User selectable

Last module = ON

All others = OFF

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Installation and Wiring

Baud Rate Settings

Position 1

OFF

Position 2

OFF

Baud Rate

57.6K

115.2K

230.4K

Disabled

Module Address Switch

The four-position Module Address DIP switch configures the BSN address in the LSL. The table below shows the address that corresponds to each setting.

Note:

OFF

Switch Position

OFF

Switch position 4 is not used.

1747-BSN Address

The figure below shows the location of the DIP switches on the

Backup Scanner.

Important:

For proper RIO link system operation, all devices must be configured for the same baud rate.

Configuration Switch

Module Address Switch

1 2 3 4 5 6

1 2 3 4

1 2 3 4 5 6

1 2 3 4

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Installation and Wiring

3-47

Backup Scanner Installation

Installation procedures for this module are the same as for any other discrete I/O or specialty module. Refer to the illustration below to identify chassis and module components listed in the procedures below.

ATTENTION: Disconnect system power before attempting to install, remove, or wire the scanner.

Important: Make sure you have set the DIP switches properly before installing the scanner.

Important:

Before installation, ensure that your modular SLC power supply has adequate reserve current capacity. The scanner requires 800 mA at 5V dc.

Insertion

1. Disconnect power.

2. Align the full-sized circuit board with the chassis card guides.

The first slot (slot 0) of the first rack is reserved for the SLC 500 processor.

3. Slide the module into the chassis until the top and bottom latches catch.

4. Attach the RIO link cable to the connector on the front of the module, behind the door. Ground the cable’s shield wire to a chassis mounting bracket. Refer to the RIO link wiring illustration.

5. Insert the cable tie in the slots.

6. Route the cable down and away from module, securing it with the cable tie.

7. Cover all unused slots with the Card Slot Filler, Catalog Number

1746-N2.

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Installation and Wiring

Module Release

Card Guide

Cable Tie

Removal

1. Disconnect power.

2. Remove all cabling.

3. Press the releases at the top and bottom of the module and slide the module out of the chassis slot.

4. Cover all unused slots with the Card Slot Filler, Catalog Number

1746-N2.

Wiring

Terminal Wiring

The Backup Scanner module contains a green removable terminal block. The terminal pinout is shown below.

ATTENTION: Disconnect power to the SLC before attempting to install, remove or wire the removable terminal wiring block.

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LSL (Line 1 - Blue)

LSL (Shield)

LSL (Line 2 - Clear)

232 / 485 (A) to CPU

232 / 485 (B) to CPU

232 / 485 (COM) to CPU

DH+ (Line 1) to CPU

DH+ (Shield) to CPU

DH+ (Line 2) to CPU

Release Screw

HSSL (Line 1- Blue)

HSSL (Shield)

HSSL (Line 2 - Clear)

232 / 485 (A) to Link

232 / 485 (B) to Link

232 / 485 (COM) to Link

RIO / DH+ (Line 1) to Link

RIO / DH+ (Shield) to Link

RIO / DH+ (Line 2) to Link

Terminal screws accept a maximum of two #14 AWG (2mm 2) wires.

Tighten terminal screws only tight enough to immobilize wires.

Maximum torque on terminal screws is 0.9 Nm (8 in-lbs.).

HSSL Wiring

Connect the HSSL to establish communication between the primary and secondary systems. Maximum cable length for the HSSL is 4.5 m

(15 ft.).

Local Status Link Wiring

If you have more than one 1747-BSN module in the same chassis, connect the LSL in series between modules in the same chassis.

RIO Link Wiring

The backup module is connected to other devices on the RIO link in a daisy chain (serial) configuration. There are no restrictions governing the space between each device, provided the maximum cable distance

(Belden 9463) is not exceeded.

A 1/2 watt terminating resistor (included with the module) must be attached across line 1 and line 2 of the connectors at each end

(scanner and last physical device) of the RIO link. The value of the resistor depends on the baud rate and extended node capability, as shown in the table that follows.

Important:

To use extended node, all devices on the RIO link must support it. Refer to each device’s user manual.

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Installation and Wiring

Using

Extended Node

Capability

Not Using

Extended Node

Capability

Baud Rate

57.6K baud

115.2K baud

230.4K baud

57.6K baud

115.2K baud

230.4K baud

Max. Cable Distance

(Belden™ 9463)

3048 m (10,000 ft.)

1524 m (5,000 ft.)

762 m (2,500 ft.)

3048 m (10,000 ft.)

1524 m (5,000 ft.)

762 m (2,500 ft.)

Resistor Size

Ω

1/2 Watt

Gray-Red-Black-Gold

150

Ω

1/2 Watt

Brown-Green-Brown-

Gold

Ω

1/2 Watt

Gray-Red-Black-Gold

Status LEDs

The table below describes the six LEDs located on the module’s front panel. To ensure that they are operating correctly, all LEDs are illuminated during power-up.

LED Definition Status & Color Indication

PRI

SEC

RIO

ERR

HSSL

FLT

Primary

Secondary

Back-up Module

Error

High-Speed Serial

Link Communication

Steady Green

Steady Amber

RIO Communication Steady Green

Fault

Flashing Green

Flashing Red

Steady Red

Off

Flashing Red

Off

Flashing Green

Off

Steady Red

Flashing Red

The module is in the primary mode.

The module is in the secondary mode.

The RIO link is working properly.

A remote device is not configured or connected correctly, or is faulted.

The RIO link has a fault. The scanner is connected incorrectly, or all devices are configured improperly, have no power, or are faulted.

There is a configuration error.

The communication channel is not configured as RIO.

The module is not ready for switchover.

The module is ready for switchover.

The link is operating with no errors.

A communications error has been detected on the HSSL.

A hardware fault has occurred.

The module is not configured properly.

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Chapter Objectives

How the 1747-BSN

Module Operates

Chapter

Operating Your SLC 500 Backup

System

In this chapter we describe how the primary system transfers data to the secondary system. We do this by describing the operation of the:

• 1747-BSN module

• SLC 500 backup system

In addition, we provide procedures for:

• starting your system

• powering up your system

• disconnecting a faulted system

• restarting a repaired system

• changing the processor’s operating mode

• editing a program on-line

In a SLC 500 backup system, the 1747-BSN module performs three distinct functions:

• automatic transfer of remote input data over the High-Speed

Serial Link (HSSL)

• transfer of data in the data table by data transfer using M files

• secondary processor remote programming capability

Automatic Transfer of Remote Input Data Over the HSSL

With automatic transfer, the primary 1747-BSN module is continually updating a copy of the remote input image table in an interface located in the secondary 1747-BSN module. This remote input data includes discrete and analog data. Automatic transfer of input image is carried out over the High-Speed Serial Link (HSSL) and is independent of the application program.

The secondary 1747-BSN module responds with current data to the remote I/O scan requests of the secondary processor, making the secondary processor “think” that it is communicating with remote I/O chassis. This response prevents remote I/O faults in the secondary processor, since the secondary BSN module is not physically connected to the remote I/O link.

In addition to providing the secondary processor a copy of the remote discrete input image table, the 1747-BSN modules in both systems work together to provide the secondary processor a copy of block transfer data read from the remote I/O chassis.

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Operating Your SLC 500 Backup System

Primary

The 1747-BSN automatically exchanges system status information when communicating with another 1747-BSN through the High-

Speed Serial Link (HSSL). Both modules are continuously communicating with each other, even when both processors are not in

Run mode. This is achieved by sending and receiving the system status words. This information can be read from either module at any time and provides for both SLC 5/0x (primary and secondary) the

“other side status”. HSSL is also used to transfer user data table data, up to 2K total per BSN module.

RS-232/485 Communication Channel

The RS-232/485 channel is a dumb communication channel which is used to switch the connection to one operator interface or other DF1 device (through RS-232/485). The communication channel relays are closed when the module is primary; otherwise the relays are open as shown in the figure below.

Secondary

SLC 5/04

1747-BSN

To Operator Interface

SLC 5/04

RIO/DH+ Communication Channel

The RIO/DH+ communication channel has a relay that is closed when the 1747-BSN module is in the primary mode; otherwise the relay is open. The communication channel supports the following configurations (The illustration on the next page shows the channel block diagram):

1. RIO: Supports the 57.6, 115.2 and 230.4 KBaud configurations.

When the module is in primary mode, it emulates all the

1747-SN Series B functionality. When the module is in secondary mode, the channel receives the input data from the primary 1747-BSN module and sends it to the SLC 5/0x, emulating the 1747-SN Series B backplane communication. As a result, the secondary SLC 5/0x “thinks” that it is really connected to the remote racks;

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(1)

Primary

2. DH+: Works under 57.6, 115.2 and 230.4 KBaud configurations.

The primary 1747-BSN enters into the DH+ network using the

DH+ node address assigned to both processors. The secondary processor will effectively assume node address n+1 for programming purposes. The commands that the primary processor receives are sent through the HSSL to the secondary

1747-BSN and then to the secondary processor (the secondary

1747-BSN emulates the DH+ network for the secondary SLC 5/

04). The replies come back to the primary 1747-BSN (again through the HSSL) and are sent to the DH+ network. This link has a functionality similar to that found in the 1785-BCM series

B and C. The link is designed to make remote programming possible for the secondary SLC 5/04. The primary SLC 5/04 is connected to the DH+ network through the primary 1747-BSN communication channel relays and sends/receives messages without any intervention of the 1747-BSN module;

3. Dumb: In this mode the communication channel is disabled and is used only as a relay that is closed when the 1747-BSN is in the primary mode and otherwise is open.

HSSL

Secondary

1747-SN emulation

SLC 5/04

(2)

Primary

1747-BSN

Remote I/0 Link

HSSL

Secondary

SLC 5/04

1747-BSN

DH+ Network

SLC 5/04

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Operating Your SLC 500 Backup System

Secondary Processor Remote Programming

Important:

The programming device must be connected through the

DH+ network and must not bypass the relay in the

1747-BSN module (if the programs in both processor are identical;e.g., if both DH+ mode addresses are the same). If you were to connect the device directly to a processor, it must be connected to the primary processor.

Therefore, if your system were to switch to the secondary system, you must then move your device to your new primary processor.

In the 1747 backup system, only the primary processor is connected to the link. The secondary processor is not physically connected, but it communicates with the secondary 1747-BSN module making this processor think that it is on the DH+ network. This separate link prevents Data Highway faults in the secondary processor.

The 1747-BSN backup module provides remote programming capability for your secondary processor. This means that even with the programming device directly connected to the primary processor, the secondary SLC-500 processor memory can be programmed and/ or monitored.

The primary 1747-BSN module provides an access point for a programming device to access the secondary processor. Using the

1747-BSN module, you can communicate from a programming device across the backup modules to the secondary processor. You must assign both the primary and the secondary processor the same node address in the DH+ link. The 1747-BSN module reserves the subsequent node address as an access-point address to the secondary processor; that is, this address is accessed by a programming device in order to program the secondary processor.

This means that if you set both processors node addresses to n, the programming device can communicate with the secondary processor with the node address n+1. Therefore, do not use node address n+1 for any other device on the DH+ network.

For example, a primary processor with node number 16 on DH+ network has the same address switch setting as the secondary processor node.

However, in this situation, the terminal addressed to station 16 attaches to the primary processor and the terminal addressed to station 17 attaches to the secondary processor.

Important:

It is recommended to assign the same node address (n) for both processors (primary and secondary) in a redundant system. You must also reserve the next node address (n+1) because this address is the access-point address to the secondary processor.

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The figure below shows how the programming device sees the secondary processor which is not physically connected to the DH+ link.

Important:

The DH+ connection to the secondary processor is meant for remote programming only. Also, only one terminal at a time may connect to the secondary processor. No DH+ messages can be sent to or from the secondary processor.

Node address = n

SLC500

Node address = n+1

BSN

HSSL

BSN

SLC500

Data Table Transfer

How the Backup

System Operates

DH+

Programming

Device

Each 1747-BSN is capable of transferring up to 2 KWord of the SLC

5/0x data table. This capacity is increased as the number of

1747-BSN modules per chassis is increased in a redundant system.

For example, a system with eight 1747-BSN’s in each chassis is capable of transferring up to 16 KWord of synchronizing data table information.

The 2 KWord that can be transferred by a single module is divided into 16 blocks of 128 words (that is equal to the maximum length of a

COP instruction). The address space M0:s.3500 through M0:s.5547 is used by the primary SLC 5/0x to send the data. The address space

M1:s.3500 through M1:s.5547 is used by the secondary SLC 5/0x to read the data from the secondary 1747-BSN. In addition, the address spaces M0:s.3400 through M0:s.3499; and M1:s.3400 through

M1:s.3499 are used for status and control exchange between the SLC

5/0x and the 1747-BSN.

Some amount of support ladder program is necessary to make both modules operate properly in a backup system.

Both processors have a transmitter program and a receiver program.

At system startup, the processor reads the Module Status Word

(MSW) and the System Status Word (SSW) from the 1747-BSN to determine its state. If the processor is in the primary state, it executes the transmitter program. If the processor is in the secondary state, it executes the receiver program.

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Primary Program

Each data block that can be transferred from the primary to secondary

SLC 5/0x is identified by its address in the M0/M1 files. The application program must transfer each block using the following procedure.

A MOV instruction is used to get the Data Transfer Status Word

(DTSW) and to see if the block can be transferred from the SLC 5/0x to the 1747-BSN (if the data block status bit is clear). When this bit is clear, the new data block must be copied to this corresponding M0 address. Then the data block control bit in the Data Transfer Control

Word (DTCW) must be set to advise the 1747-BSN that this new data block is ready to transfer to the secondary system. This bit must be held set until the corresponding bit in the DTSW is set by the

1747-BSN. The bit must then be cleared.

Secondary Program

For each block that can be received by the secondary SLC 5/0x, its application program must do the following procedure.

A MOV instruction is used to get the Data Transfer Status Word

(DTSW) and to see if new data for the block is ready for reading in the secondary 1747-BSN module. When this bit is set, the new data block must be copied from the 1747-BSN M1 file. Then its corresponding bit in the Data Transfer Handshake Word (DTHW) must be set to advise the 1747-BSN that the data block was already received. This bit must be held set until the corresponding bit in

DTSW is cleared by the 1747-BSN module. The bit must then be cleared.

Backup System Theory of Operation

A redundant system using the 1747-BSN can be initially defined as an “Asynchronized Data Transfer” system. While the Input Image

Table is automatically acquired from the RIO link by the secondary system, the Data Table is transferred by an application program written by the user. It is recommended that you minimize the amount of data to be transferred from the primary to the secondary processor because the program logic generates the same outputs based on the same inputs.

All timer and counter values must be transferred at least once because the primary and backup processors may have started at different times and are not synchronized. Therefore, timer and counter data may be different in the two processors. For example, after a faulted processor is repaired and reinstalled as a backup, the timer and counter accumulated values, as well as the control words, in the two processors are different.

The number of data table words to be transferred from a primary to a secondary processor is dependent on the user program and/or user architecture.

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Operating Your SLC 500 Backup System

4-57

Startup Sequencing

When the system is powered up for the first time, the following sequence must be followed:

1. Disconnect both the primary and secondary SLC 5/0x from DH+ or DH485

2. Download programs containing the desired DH+ or DH485 node address to each processor. Leave both SLC 5/0x in program mode, and power down both systems.

3. Apply power to the system that is intended to be primary;

4. Apply power to the system that is intended to be secondary;

5. Change the primary SLC processor to Run mode;

6. Change the secondary SLC processor to Run mode.

Power-up Sequencing

To determine the primary and secondary systems, use the following powerup sequence:

1. Apply power to the system that is intended to be primary;

2. After the primary SLC 5/0x has been powered-up and is operating correctly, apply power to the system that is intended to be secondary.

If both systems are powered-up at the same time, they use a “talkand-listen algorithm” to determine which system is going to be primary and which is going to be secondary. The RIO and DH+ relays remain open until only one of the systems assumes primary status.

This ensures that only one of the SLC 5/0x processors takes control over the RIO and DH+ links.

Processor Mode

Change Sequencing

The 1747-BSN does not control the operating mode of the SLC 5/0x in either the primary or the backup systems. If a processor mode change is required, it should be done primarily in the secondary system. After that, if required, the processor mode change should also be done in the primary processor.

If the primary operating mode is changed from Run mode to Program mode, the secondary system takes control.

ATTENTION: Use the processor mode change key to change the primary operating mode. Unexpected operation or system shutdown could occur if you use a programming terminal to change the primary operating mode from Remote Run to Remote Program.

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Operating Your SLC 500 Backup System

Fail-over Sequencing

Power Down

Sequencing

Restarting a failed system

When the primary system fails, the communications relays are opened immediately. The primary 1747-BSN ceases its data transfer function and sends switching commands to the secondary 1747-BSN.

After all the RIO communications terminate, the secondary communication channel relays are closed. Then the former secondary

SLC is ready to take control of the system.

Since the secondary’s input image table has been loaded on-line with real data from the Smart Switch, the application program does not have to delay the use of its input image table until the completion of at least one complete RIO scan. The secondary’s (now primary) input image table always has valid data.

No special considerations (beyond the standard precautions for a programmable controller) are required when powering down the system. Power down should begin with the secondary system and proceed to the primary. If the primary system is powered down first, a switchover occurs.

A failed system (that has been repaired) can be restarted as described in the following sequence. It is not necessary to power-down or change the mode of primary SLC 5/0x.

1. Set the secondary SLC 5/0x (processor of the repaired system) to program mode;

2. Apply power to the secondary system;

3. Download the applications program to the secondary SLC 5/0x;

4. Change the backup processor mode of operation from Program mode to Run mode.

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Chapter

Scanner Configuration and

Programming

This chapter contains information necessary to:

• understand remote I/O image files

• understand RIO configuration using G files

• control and view RIO devices using the M0 and M1 files

• understand slot addressing

• quickly configure the RIO Scanner

Understanding Remote

Input and Output

Image Files

The SLC system allows you to assign up to 32 words of input and output image data to a scanner. This allows your scanner to access a maximum of four full logical racks (512 input and output points) of data from remote devices.

The illustration below shows how logical racks, logical groups, and words are allocated within the I/O image files. Note that this illustration describes the input image file. The scanner’s output image file is the same, except that its addressing scheme starts with O:e.O and ends with O:e.31.

Logical Rack 0 Group 0

Logical

Logical Rack 0 Group 2

Logical Rack 0 Group 3

Rack 0

Logical Rack 0 Group 1

Logical Rack 0 Group 4

Logical Rack 0 Group 5

Logical Rack 0 Group 6

Logical Rack 0 Group 7

Logical Rack 1 Group 0

Logical Rack 1 Group 1

Logical

Logical Rack 1 Group 2

Logical Rack 1 Group 3

Rack 1

Logical Rack 1 Group 4

Logical Rack 1 Group 5

Logical Rack 1 Group 6

Logical Rack 1 Group 7

Logical Rack 2 Group 0

Logical

Logical Rack 2 Group 1

Logical Rack 2 Group 2

Rack 2

Logical Rack 2 Group 3

Logical Rack 2 Group 4

Logical Rack 2 Group 5

Logical Rack 2 Group 6

Logical

Rack 3

Logical Rack 2 Group 7

Logical Rack 3 Group 0

Logical Rack 3 Group 1

Logical Rack 3 Group 2

Logical Rack 3 Group 3

Logical Rack 3 Group 4

Logical Rack 3 Group 5

Logical Rack 3 Group 6

Logical Rack 3 Group 7

Word 16

Word 17

Word 18

Word 19

Word 20

Word 21

Word 22

Word 23

Word 24

Word 25

Word 26

Word 27

Word 28

Word 29

Word 30

Word 31

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

15 14 13 12 11 10 9 8 7

6 5 4 3 2

1 0

I:e.19

I:e.20

I:e.21

I:e.22

I:e.23

I:e.24

I:e.25

I:e.13

I:e.14

I:e.15

I:e.16

I:e.17

I:e.18

I:e.26

I:e.27

I:e.28

I:e.29

I:e.30

I:e.31

I:e.6

I:e.7

I:e.8

I:e.9

I:e.10

I:e.11

I:e.12

I:e.0

I:e.1

I:e.2

I:e.3

I:e.4

I:e.5

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Scanner Configuration and Programming

The 1747-BSN module’s I/O image structure is described below:

• The I/O image file consists of four logical racks (numbered 0, 1,

2, and 3) of input image and four logical racks of output image.

• Each logical rack consists of eight logical groups (numbered 0,

1, 2, 3, 4, 5, 6, and 7).

• Each logical group consists of two words (an input word and an output word).

• Each word consists of two bytes (a high and a low byte). Low byte is bits 0-7 and high byte is bits 8-15.

• Each byte consists of eight bits, with each bit having the ability to control one discrete I/O point.

RIO Configuration Using G Files

When you program your SLC system, use the G file to configure the scanner’s I/O image file. The Backup Scanner’s G file configuration is based on the devices that you have on the RIO link. G file configuration consists of setting logical device starting addresses and the logical device image size of each physical device/adapter with which the scanner communicates.

You enter G file configuration information using programming software. See “M0-M1 Files and G Files” on page B-1 for further details.

Neither your application program nor your programming device can access or alter the G file while on-line with the processor. To change the G file you must go off-line into the program file, make any necessary changes, and download the program containing the altered configuration. The G file consists of five words which are described below.

Word 0 - contains scanner information for the SLC processor. Your programming device automatically sets up Word 0. Do not attempt to alter word 0.

Important:

The term “primary” is used in conjunction with the term

“complementary,” when referring to a complementary

I/O configuration. Primary refers to I/O image space found in Logical Racks 0 through 3 when in complementary I/O mode. Normal refers to the same image space (racks 0-3) when not in complementary I/O mode.

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Scanner Configuration and Programming

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Word 1, Primary/Normal Logical Device Address - specifies the logical starting address of each primary/normal RIO link device. The logical address consists of the logical rack number (0, 1, 2, or 3) and starting logical group (0, 2, 4, or 6). Each bit in this word represents a logical address. To specify an address, place a 1 at the bit corresponding to the starting logical address of each logical device.

Word 2, Primary/Normal Device Logical Image Size - specifies the logical image size (amount of scanner I/O image) of the devices set in word 1. As with word 1, these bits correspond to RIO logical rack and logical group numbers. To specify image size, place a 1 at each group a device occupies.

Word 3, Complementary Logical Device Address - specifies the logical starting address of each complementary RIO link device. The logical address consists of the logical rack number (8, 9, 10, or 11 because a complementary device is always 8 above its primary) and starting logical group (0, 2, 4, or 6). Each bit in this word represents a logical address. To specify an address, place a 1 at the bit corresponding to the starting logical address of each logical device.

Word 4, Complementary Device Logical Image Size - specifies the logical image size (amount of scanner I/O image) of the complementary devices set in word 3. As with word 3, these bits correspond to RIO logical rack and logical group numbers. To specify image size, place a 1 at each group a device occupies.

Important:

Setting device addresses in word 3 of the G file configures the system to operate in the complementary

I/O mode. Not setting device addresses in word 3 causes the system to operate only in the primary/normal mode.

If you wish to operate in the complementary mode and you only have primary devices configured, word 3 of the

G file must be set to a decimal “1,” and word 4 of the G file must be equal to zero.

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Scanner Configuration and Programming

Bit Number

I/O Mix, Word 0

Primary/Normal Logical

Device Address,

Word 1

Primary/Normal Logical

Image Size

Word 2

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

0 0 1 0 0 0 0 0

RIO Logical Rack 3 Starting

RIO Logical Rack 2

Logical Group

Starting Logical Group

0 0 1 0 0 0 0 0

RIO Logical Rack 1 Starting

Logical Group

RIO Logical Rack 1 Starting

Logical Group

Contains scanner information for the SLC.

Your programming device automatically sets the scanner Information.

Specifies the RIO starting addresses of primary/ normal logical devices.

RIO Rack 3

Image Size

RIO Rack 2

Image Size

2 0

0 1

RiO Rack 1

Image Size

4 2

1 1

0 6

RIO Rack 0

Image Size

Specifies the logical image size assigned to primary/ normal logical devices set in Word 1.

Complementary Logical

Device Address

Word 3

Complementary Logical

Image Size,

Word 4

RIO Logical Rack 11

Starting Logical Group

RIO Logical Rack 10

Starting Logical Group

RIO Rack 11

Image Size

1 1

0 6

RIO Rack 10

Image Size

2 0

RIO Logical Rack 9 Starting

Logical Group

RIO Logical Rack 8 Starting

Logical Group

Specifies the RIO starting addresses of complementary logical devices.

RIO Rack 9

Image Size

0 6

RIO Rack 8

Image Size

Specifies the logical image size assigned to complementary logical devices set in Word 3.

Note: A complementary logical rack is always numbered 8 above its primary logical rack. Also, logical racks 8, 9, 10, and 11 are sometimes referred to as complementary logical racks 0, 1, 2, and 3.

Quarter Logical Rack Device

Full Logical Rack Device

Half Logical Rack Device

Three Quarter Logical Rack Device

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Rules for Configuring the Scanner

General

• The smallest portion of the scanner’s I/O image that can be allocated to a single RIO device is two logical groups (1/4 logical rack).

• If a device is configured in word 1, there must be image allocated to it in word 2. This rule also applies to words 3 and 4 with the following exception: if word 3 = 1 and word 4 = 0, the complementary mode is selected even though no complementary devices are configured.

• A logical device’s starting group must begin at even group numbers (0, 2, 4, or 6). Each bit in words 2 and 4 represent an even logical group number.

Concerning Complementary I/O

• It is valid for you to have a complementary device configured even if no associated primary device exists. Also, complementary devices do not have to be the same logical image size as the primary device.

• G file words 1 and 2 can both be zero (no primary devices).

However, in this case there must be at least one complementary device configured in G file words 3 and 4.

• If there is at least one primary device configured in G file words

1 and 2, then words 3 and 4 can both be zero, or the G file size can be set to 3 (complementary mode not selected).

• The starting group of the primary and complementary chassis should be the same if they share the same image space. If the starting group is not the same, the image of the complementary device must not “cross over” into the space of a primary device.

For example, if a primary device exists at Logical Rack 1,

Logical Group 4, the maximum size of a complementary device at Logical Rack 9, Logical Group 0 is a half logical rack. The image does not cross over into Logical Group 4.

• A complementary device cannot be configured at locations where primary devices are configured unless they both start at the same location.

• If you configure your system so that complementary I/O is not selected (words 3 and 4 are zero), you must not set up any of the actual devices to be in the primary mode. If you do, the system flags the device as faulted and prevents the device from running.

• Control functions (i.e., device inhibit, device reset, and device output reset) are only selectable for the primary device, but also apply to the complementary device. Control functions for complementary devices cannot be exclusively enabled.

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Scanner Configuration and Programming

Example G File Showing Primary and Complementary Device Configurations

In the example that follows, the scanner is configured to communicate with primary and complementary devices. Below are the device addresses and image sizes:

• Logical Racks 0/8, Logical Group 2 contain a primary 3/4 logical rack device and a complementary 3/4 logical rack device.

• Logical Racks 1/9, Logical Group 0 contain no primary device and a complementary 1/2 logical rack device.

• Logical Racks 1/9, Logical Group 6 contain a primary 1/4 logical rack device and a complementary 1/4 logical rack device.

• Logical Racks 2/10, Logical Group 0 contain a primary 3/4 logical rack device and a complementary 1/4 logical rack device.

• Logical Racks 3/11, Logical Group 2 contain a primary 1/4 logical rack device and a complementary 1/2 logical rack device.

• Logical Racks 3/11, Logical Group 6 contain a primary 1/4 logical rack device and no complementary device.

Bit Number

I/O Mix, Word 0

Primary/Normal Logical

Device Address,

Word 1

RIO Logical Rack 3 Starting

RIO Logical Rack 2

Logical Group

Starting Logical Group

RIO Logical Rack 1 Starting

Logical Group

RIO Logical Rack 0 Starting

Logical Group

Primary/Normal Logical

Image Size

Word 2

RIO Rack 3

Image Size

2 0

RIO Rack 2

Image Size

1 1

RiO Rack 1

Image Size

0 6

RIO Rack 0

Image Size

Complementary Logical

Device Address

Word 3

RIO Logical Rack 11

Starting Logical Group

6 4 2

0 0 1

RIO Logical Rack 10

Starting Logical Group

6 4 2 0

0 0 0 1

RIO Logical Rack 9 Starting

RIO Logical Rack 8 Starting

Logical Group

6 4 2 0 6 4 2 0

1 0 0 1 0 0 1 0

Complementary Logical

Image Size,

Word 4

RIO Rack 11

Image Size

4 2

1 1

RIO Rack 10

Image Size

RIO Rack 9

Image Size

0 6

RIO Rack 8

Image Size

Illegal Configuration Examples

Having a primary device configured at Logical Rack 1, Logical

Group 2 (bit 5) would be illegal since this image space is already being used by a complementary device. Having a complementary device configured at Logical Rack 10, Logical Group 2 (bit 9) would also be illegal since this image space is already being used by a primary device.

Publication 1747-6.22

Logical

Rack 0

Logical

Rack 1

Logical

Rack 2

Logical

Rack 3

Scanner Configuration and Programming

5-65

Note that the complementary device at Logical Rack 8, Logical

Group 2 could be an ASB using 10 words (1-1/4 logical racks) of data, and thereby cross into RIO Logical Rack 9.

The G file configuration above would provide the primary and complementary input images to the scanner, which are illustrated on the following pages. Note that the output images would be the same.

Example Scanner Input Image of the Primary Devices

Below are the primary device addresses and sizes. The following figure contains complementary device addresses and sizes.

• Device 1 - starting at Logical Rack 0, Logical Group 2 is a primary 3/4 logical rack device.

• Logical Rack 1, Logical Group 0 contains no primary device.

• Device 2 - starting at Logical Rack 1, Logical Group 6 is a primary 1/4 logical rack device.

• Device 3 - starting at Logical Rack 2, Logical Group 0 is a primary 3/4 logical rack device.

• Device 4 - starting at Logical Rack 3, Logical Group 2 is a primary 1/4 logical rack device.

• Device 5 - starting at Logical Rack 3, Logical Group 6 is a primary 1/4 logical rack device.

e= slot number of the SLC chassis containing the scanner.

13 12 11 10 9 8 7 6 5 4 3

Word 12

Word 13

Word 14

Word 15

Word 16

Word 17

Word 18

Word 19

Word 20

Word 21

Word 22

Word 23

Word 24

Word 25

Word 26

Word 27

Word 28

Word 29

Word 30

Word 31

Word 0

Word 1

Word 2

Word 3

Word 4

Word 5

Word 6

Word 7

Word 8

Word 9

Word 10

Word 11

I:e.17

I:e.18

I:e.19

I:e.20

I:e.21

I:e.22

I:e.23

I:e.10

I:e.11

I:e.12

I:e.13

I:e.14

I:e.15

I:e.16

I:e.24

I:e.25

I:e.26

I:e.27

I:e.28

I:e.29

I:e.30

I:e.31

I:e.0

I:e.1

I:e.2

I:e.3

I:e.4

I:e.5

I:e.6

I:e.7

I:e.8

I:e.9

Device 1

Device 2

Device 3

Device 4

Device 5

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Scanner Configuration and Programming

Example Scanner Input Image of the Complementary Devices

Below are the complementary device addresses and sizes. The following figure contains primary device addresses and sizes.

• Device 6 - starting at Logical Rack 8, Logical Group 2 is a complementary 3/4 logical rack device.

• Device 7 - starting at Logical Rack 9, Logical Group 0 is a complementary 1/2 logical rack device.

• Device 8 - starting at Logical Rack 9, Logical Group 6 is a complementary 1/4 logical rack device.

• Device 9 - starting at Logical Rack 10, Logical Group 0 is a complementary 1/4 logical rack device.

• Device 10 - starting at Logical Rack 11, Logical Group 2 is a complementary 1/2 logical rack device.

• Logical Rack 11, Logical Group 6 has no complementary device.

Bit Number(Decimal)

Logical

Rack 0

Logical

Rack 1

Logical

Rack 2

Logical

Rack 3

Word 22

Word 23

Word 24

Word 25

Word 26

Word 27

Word 28

Word 29

Word 30

Word 31

Bit Number (octal)

Word 11

Word 12

Word 13

Word 14

Word 15

Word 16

Word 17

Word 18

Word 19

Word 20

Word 21

Word 0

Word 1

Word 2

Word 3

Word 4

Word 5

Word 6

Word 7

Word 8

Word 9

Word 10

13 12 11 10 9 8 7

6 5 4 3 2 1

I:e.19

I:e.20

I:e.21

I:e.22

I:e.23

I:e.24

I:e.25

I:e.13

I:e.14

I:e.15

I:e.16

I:e.17

I:e.18

I:e.26

I:e.27

I:e.28

I:e.29

I:e.30

I:e.31

I:e.7

I:e.8

I:e.9

I:e.10

I:e.11

I:e.12

I:e.0

I:e.1

I:e.2

I:e.3

I:e.4

I:e.5

I:e.6

Device 6

Device 7

Device 8

Device 9

Device 10

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Considerations When

Configuring Remote I/

O

The following sections contain information that you should understand before you configure your scanner’s G file.

G File Considerations

• You can only change the RIO configuration by modifying the G file while offline in your program file. Your application program cannot access the G file, nor can you access it while online with your programming device. However, your SLC control program can dynamically inhibit and uninhibit RIO devices via the M0 file.

• RIO devices larger than 1 logical rack appear as multiple devices on the RIO link. Refer to the Crossing Logical Rack Boundaries section below.

• The address and size of the devices you list in the G file must match the settings of each RIO device.

Crossing Logical Rack

Boundaries

You express remote I/O image boundaries in an even number of groups. For example, the 1747-ASB image can be any size from two logical groups up to 32 logical groups (four logical racks), in 2logical group increments.If the scanner image assigned to an adapter is greater than 8 logical groups (one logical rack), the image crosses logical rack boundaries. If the scanner image assigned to an adapter is less than 8 logical groups, it too can cross a logical rack boundary depending upon the starting logical group number. The significance of crossing logical rack boundaries is discussed in the next section.

Examples of Crossing Logical Rack Boundaries

Examples 1 and 2 that follow show adapters with logical image sizes that cross logical racks 0 and 1. The image size of the adapter in example 1 consumes all of logical rack 0 (eight logical groups) and half of logical rack 1 (four logical groups). The image size of the adapter in example 2 consumes two groups in logical rack 0 and four groups in logical rack 1.

Logical

Rack 0

Logical

Rack 1

Crossing Logical Rack Boundries - Example 1

Scanner Input or Output Image

15 8 7 0

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Adapter

Image

Adapter image is 12 logical groups in size and crosses a logical rack boundary due to its size.

Crossing Logical Rack Boundries - Example 2

Scanner Input or Output Image

15 8 7 0

Logical

Rack 0

Logical

Rack 1

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Adapter

Image

Adapter image is 6 logical groups in size and crosses a logical rack boundary due to its starting logical group number.

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Scanner Configuration and Programming

Creating More than One Logical Rack Device

RIO discrete transfers occur on a logical device basis, not on an adapter basis. A logical device is any portion of a logical rack that is assigned to a single adapter.

When the scanner image assigned to an adapter is more than one logical device, the scanner sees the single physical device as multiple logical devices on the RIO link. The scanner communicates with each logical device independently, even if the logical devices are all assigned to one adapter. If a physical device image is more than one logical device, the following is true:

• The scanner does not update all of the adapter image at the same time. The number of logical devices determines the number of

RIO discrete transfers that are needed to update the entire adapter image.

• The adapter may receive different communication commands for each logical device. In this case, the adapter decides which command it responds to.

In this example the adapter is configured to start at Logical Rack 0,

Logical Group 0, and uses 14 words of I/O image. Note that two RIO discrete transfers are required for the scanner to update the adapter image containing two logical devices.

Logical

Rack 0

Logical

Rack 1

Scanner Input or Output Image

15 8 7 0

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Logical

Device

Logical

Device

Adapter

Image

Understanding M Files

M Files Overview

The scanner provides RIO device control and status information through the M0 and M1 files. The M0 file is a control file. The M1 file is a status file.

There is no image for M file data in SLC processors as there is for I/O data. The M files are buffers in the BSN module, accessible only via ladder logic instructions that address them. Each occurrence of a ladder instruction addressed with an M-file address is an interrupt to the ladder program scan. This is similar to the way Immediate I/O

Instructions operate.

Instructions with the M0 file addressed write data to the M0 file in the

BSN. Instructions with the M1 file addressed read data from the M1 file in the BSN.

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M-file bits/words in the ladder program, therefore, impact the ladder scan time. If scan time is critical, use COP instructions to copy blocks of M1 file data to processor data file addresses throughout the program. It is more efficient to do one large M-file transfer than to do many small transfers.

It is also more efficient to address instructions in the ladder program using internal data files (binary, integer, etc.). Then use COP instructions to copy this data file to the M0 file in one large block at the end of the program. Refer to the ladder example that follows. For more information on M files, refer to appendix B. You can find M file information relating to Block Transfer operations in chapter 7, RIO

Block Transfer.

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Scanner Configuration and Programming

Rung 2:0

To decrease program scan time, copy the first four words of the M1 file to a binary file and use these addresses throughout the program to access block transfer done, error, data, etc. information without interrupting the program scan many times.

| +COP±±±±±±±±±±±±±±±±+ |

|±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±+COPY FILE | |

| |Source #M1:1.100| |

| |Dest #B3:0| |

| |Length 4| |

| +±±±±±±±±±±±±±±±±±±±+ |

Rung 2:1

Examine B3/13 (B3: 0/13), an internal storage bit, to determine when a block transfer is done. Note that examining multiple individual M-file bits directly (every scan) can measurably increase processor scan time

| BT DONE |

| B3 +COP±±±±±±±±±±±±±±±±+ |

|±±±±] [±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±+COPY FILE | |

| 13 |Source #M1:1.110| |

| |Dest #N10:0| |

| |Length 64| |

| +±±±±±±±±±±±±±±±±±±±+ |

Rung 2:2

Examine B3/12 (an internal storage bit) to determine if a BT error occurred. Buffer the BT status from B3:3 if an error does occur.

| B3 +MOV±±±±±±±±±±±±±±±±+ |

|±±±±] [±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±±+MOVE |

| 12 |Source B3:3| |

| | 0000000000000000| |

| |Dest N10:64| |

| | 0| |

| +±±±±±±±±±±±±±±±±±±±+ |

Rung 2:3

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Important:

If you are using an SLC 5/02 processor M file data cannot be directly monitored. To monitor M files, you must move the M file words into an SLC file that can be monitored, e.g., an integer “N” file. SLC 5/03 or later processors allow you to monitor M files directly.

However, do not address M file bits more than necessary throughout your application program. The processor accesses M files like immediate I/O. Therefore, excessive addressing of M files can greatly increase SLC processor scan time. For more information on M files, refer to Appendix B.

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Device

Inhibit

Control

M0 Control File Description

You can control the operation of individual devices on the RIO link with M0 word 8 through M0 word 27 (M0:e.8 through M0:e.27).

Through your application program, you can use the M0 file to:

• Device Inhibit - command the 1747-BSN module to stop scanning an RIO device by using words 8 - 11.

• Device Reset - command an RIO device’s outputs to reset while the

SLC processor is in Run or Test mode by using words 16 - 19.

• Remote Output Reset - command an RIO device’s outputs to reset upon the SLC processor leaving Run mode (regardless of the RIO device’s Hold Last State setting), or while in Test mode by using words 24 - 27.

If you do not modify the Device Reset and Remote Output Reset words, the device outputs reflect the scanner output image whenever the SLC processor is in Run mode. If the SLC processor is in

Program, Test, or Fault mode, it instructs the device to reset its outputs.

M file data is nonretentive. Upon entering Run or Test modes, the

SLC processor sets the M0 file to a default state. The processor does not use the M0 file until a full program scan occurs (after entering

Run mode). This allows you to change the M file settings before they take effect.

Important:

The 1747-BSN module does not use M0 words 0 - 7.

MO (Control) File- RIO Device Control Words

Logical Rack 0 Device Inhibit Word 8

Logical Rack 1Device Inhibit Word 9

Logical Rack 2 Device Inhibit Word 10

Logical Rack 3 Device Inhibit Word 11

x x x x

Device

Reset

Control

Logical Rack 0 Device Inhibit Word 16

Logical Rack 1 Device Inhibit Word 17

Logical Rack 2 Device Inhibit Word 18

Logical Rack 3 Device Inhibit Word 19

Output

Reset

Control

Logical Rack 0 Remote Output Reset Word 24

Logical Rack 1 Remote Output Reset Word 25

Logical Rack 2 Remote Output Reset Word 26

Logical Rack 3 Remote Output Reset Word 27 x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x

e = slot number of the SLC rack containing the scanner x = bit not used/defined

Important:

Control functions (i.e., device inhibit, device reset, and device output reset) are only selectable for the primary device, but also apply to the complementary device.

Control functions for complementary devices cannot be exclusively enabled.

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M0 File - RIO Device

Inhibit Control

Bit Number (decimal)

Logical Rack 0 Device Inhibit Word 8

Logical Rack 1Device Inhibit Word 9

Logical Rack 2 Device Inhibit Word 10

Logical Rack 3 Device Inhibit Word 11

M0 Words 8 through 11 - you use these words to command the scanner to stop scanning logical racks 0, 1, 2, and 3. Bits 0 - 3 in each word correspond to I/O group locations within logical racks 0, 1, 2, and 3.

To stop scanning (inhibit) a device listed in the configuration (G) file, set the bit corresponding to the starting group address of the device to

1. Setting bits that do not correspond to the device logical starting

group address does not inhibit the device. To resume scanning a device, reset the bit (which corresponds to the starting group address of the device) to 0.

Inhibiting a device does not affect the current settings of the Device

Fault Status (words 12 - 15 of the M1 file). Inhibited devices

eventually time out and either return to their last state or reset

(depending on the device’s last state setting).

Default:

When the processor enters the Run mode, the scanner automatically inhibits any device not configured in the G file (bit set to 1). Attempting to inhibit an unconfigured device has no effect.

MO (Control) File Words 8 through 11

Not Defined

15 x x x x

14 x x x x

13 x x x x

12 x x x x

11 x x x x

10 x x x x

9 x x x x

8 x x x x

7 x x x x

6 x x x x

5 x x x x

4 x x x x

Starting Group

2 1

M0 File

M0:e.8

M0:e.9

M0:e.10

M0:e.11

e = slot number of the SLC rack containing the scanner x = not used/defined

Example of Device Inhibit Control

The 1747-BSN Scanner inhibits (sets to 1) the bits in M0:e.8 through

M0:e.11 (by default) wherever there are no configured devices present. The illustration below compares the configured devices

(G file word 2) to the groups that the scanner automatically inhibits.

G File

RIO Logical Rack 3

Starting Group

RIO Logical Rack 2

Starting Group

RIO Logical Rack 1

Starting Group

RIO Logical Rack 0

Starting Group

Device Address, Word 1

MO (Control) File

Bit Number (decimal)

Logical Rack 0 Device Inhibit Word 8

Logical Rack 1Device Inhibit Word 9

Logical Rack 2 Device Inhibit Word 10

Logical Rack 3 Device Inhibit Word 11

15 x x x x

14 x x x x

13 x x x x

12 x x x x

11 x x x x

10 x x x x

9 x x x x

8 x x x x

7 x x x x

6 x x x x

5 x x x x

4 x x x x

e = slot number of the SLC rack containing the scanner x = not used/defined

M0 File

M0:e.8

M0:e.9

M0:e.10

M0:e.11

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M0 File - RIO Device

Reset Control

Logical Rack 0 Device Inhibit Word 16

Logical Rack 1Device Inhibit Word 17

Logical Rack 2 Device Inhibit Word 18

Logical Rack 3 Device Inhibit Word 19

M0 Words 16 through 19 - you use these words to command a reset

(0) of RIO device outputs when the SLC processor is in Run or Test mode. This allows you to selectively reset logical device outputs based on a previous condition(s) that you defined. Bits 0 - 3 correspond to the logical I/O group locations within logical racks 0, 1,

2, and 3.

To command an RIO device to a reset (0) condition (from Run or Test mode), set the bit corresponding to the starting logical address of the device to 1. Setting bits that do not correspond to a device starting address does not force a reset. To remove the reset condition, reset the bit (corresponding to the device logical starting address) to 0. Refer to the mode table below.

Default:

The SLC processor resets all bits in this field to 0 when it enters Run or Test mode.

MO (Control) File Words 16 through 19

Not Defined

15 x x x x

14 x x x x

13 x x x x

12 x x x x

11 x x x x

10 x x x x

9 x x x x

8 x x x x

7 x x x x

6 x x x x

5 x x x x

4 x x x x

e = slot number of the SLC rack containing the scanner x = bit not used/ defined

Starting Group

4 2

3 2 1

M0 File

M0:e.16

M0:e.17

M0:e.18

M0:e.19

Example of Device Reset Control

The application has commanded the device starting at Logical Rack

0, Group 0 (M0:e.16/0) to a reset condition (bit set to 1). The default setting for all device reset bits is 0.

G File

RIO Logical Rack 3

Starting Group

6 4 2 0

0 0 1 0

RIO Logical Rack 2

Starting Group

4 2 0

0 0 1 0

RIO Logical Rack 1

Starting Group

6 4 2 0

0 0 0 1

RIO Logical Rack 0

Starting Group

6 4 2

1 0 0

Device Address, Word 1

MO (Control) File

Bit Number (decimal)

Logical Rack 0 Device Inhibit Word 16

Logical Rack 1Device Inhibit Word 17

Logical Rack 2 Device Inhibit Word 18

Logical Rack 3 Device Inhibit Word 19

15 x x x x

14 x x x x

13 x x x x

12 x x x x

11 x x x x

10 x x x x

9 x x x x

8 x x x x

7 x x x x

6 x x x x

5 x x x x

4 x x x x

M0 File

M0:e.16

M0:e.17

M0:e.18

M0:e.19

e = slot number of the SLC rack containing the scanner x = bit not used/defined

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M0 File - Remote

Output Reset Control

M0 Words 24 through 27 - use these words to command a logical device to reset all of its outputs when the SLC processor leaves the

Run mode and enters the Test, Program, or Fault mode (regardless of the device’s Hold Last State setting).

Resetting the bit (corresponding to the starting address of a device) to

0 allows the Hold Last State switch on the logical device to determine output operation when the SLC processor leaves the Run mode.

Setting the bit to 1 commands all outputs off (regardless of the device’s Hold Last State setting).

Only the device’s logical starting address bit matters. Setting other bits has no effect. Bits 0 - 3 correspond to I/O group locations within logical racks 0, 1, 2, and 3.

Default: When the processor enters Run or Test mode, the scanner sets the starting address bit of each device configured in the G file to

ATTENTION: The use of the device’s Hold Last State switch can result in its outputs remaining energized when not under control of the SLC processor. Only experienced SLC programmers should use this function.

Bit Number (decimal)

Logical Rack 0 Device Inhibit Word 24

Logical Rack 1Device Inhibit Word 25

Logical Rack 2 Device Inhibit Word 26

Logical Rack 3 Device Inhibit Word 27

MO (Control) File Words 24 through 27

Not Defined

15 x x x x

14 x x x x

13 x x x x

12 x x x x

11 x x x x

10 x x x x

9 x x x x

8 x x x x

7 x x x x

6 x x x x

5 x x x x

4 x x x x

Starting Group

2 0

M0 File

M0:e.24

M0:e.25

M0:e.26

M0:e.27

e = slot number of the SLC rack containing the scanner x = not used/defined

Example of Remote Output Reset Control

By default the scanner sets the bits in M0:e.24 through M0:e.27 to 1 wherever there are configured devices present. This commands all devices’ outputs to reset regardless of their Hold Last State switch.

The application program can remove commanded reset of devices by resetting bits to 0.

G File

Device Address, Word 1

MO (Control) File

Bit Number (decimal)

Logical Rack 0 Device Inhibit Word 24

Logical Rack 1Device Inhibit Word 25

Logical Rack 2 Device Inhibit Word 26

Logical Rack 3 Device Inhibit Word 27

RIO Logical Rack 3

Starting Group

RIO Logical Rack 2

Starting Group

RIO Logical Rack 1

Starting Group

RIO Logical Rack 0

Starting Group

15 x x x x

14 x x x x

13 x x x x

12 x x x x

11 x x x x

10 x x x x

9 x x x x

8 x x x x

7 x x x x

6 x x x x

5 x x x x

4 x x x x

e = slot number of the SLC rack containing the scanner x = not used/defined

M0 File

M0:e.24

M0:e.25

M0:e.26

M0:e.27

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Device Reset and Remote Output Reset Considerations From this mode

The 1747-BSN Scanner Device Reset words (M0:e.16 to M0:e.19) and the Remote Output Reset words (M0:e.24 to M0:e.27) operate in conjunction with each RIO device to determine the state of that RIO device’s outputs. The output control information that the scanner sends to the RIO device depends on how you configure these bits.

The RIO device acts on the output control information in accordance with its functionality and configuration. To fully understand how a specific device responds to the Device Reset and Remote Output

Reset words, you must determine the operation of the RIO device. To determine RIO device output operation, refer to that device’s user manual.

ATTENTION: When using the Device Reset and

Remote Output Reset words, you must completely understand and fully test all device output operations before beginning normal system operation.

To properly use the Device Reset and Remote Output Reset words, you must consider the output control information sent to the devices during two SLC processor operating conditions:

•

Τ he SLC processor is in any given mode (Run, Program, Test, or

Fault).

• The SLC processor is leaving any mode and entering another.

If you do not modify the Device Reset and Remote Output Reset words, the device outputs reflect the scanner output image whenever the SLC processor is in Run mode. If the SLC processor is in

Program, Test, or Fault mode, it instructs the device to reset its outputs.

If you modify the default settings, the Device Reset and Remote

Output Reset words change. The table on the following page contains examples of what changes occur. The information in the table is

based on the assumption that the scanner’s slot is always enabled and the RIO link device is communicating with the scanner.

To determine how the Device Reset and Remote Output Reset words operate, locate the box where the row and column are headed by the modes in question. The shaded boxes represent the Device Reset and

Remote Output Reset word operation while in that mode.

Example 1 - When powering up into Run mode, the scanner, by default, resets the appropriate bit in the Device Reset word to 0. The appropriate bit in the Remote Output Reset word is set to 1. As a result, the RIO link device outputs reflect the scanner’s output image.

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Power-up

Example 2 - Once the SLC processor is in Run mode, the bits in the

Remote Output Reset word have no effect on the RIO link device’s outputs. Setting the appropriate bits in the Device Reset Word to 1 instructs the RIO link device to reset its outputs.

Example 3 - When going from Run to Program mode, if both of the appropriate bits in the Device Reset and Remote Output Reset words are reset to 0 before leaving Run mode, the RIO link device is instructed to decide whether to hold its last output state or to reset its outputs.

To this mode

Test

Run

DR = 0

ROR = 1

Default values are set automatically. Outputs reflect those of the scanner output image.

Program

DR = X

ROR = X

Run

Test

ROR = X

DR = 0

Outputs are unchanged.

DR = 1

Outputs are turned OFF.

DR = 0

In this instance, the last

ROR = 0 state switch setting is valid.

DR = 0

In this instance, the last

ROR = 0 state switch setting is valid.

DR = 0

ROR = 1

Default values are set automatically.

Outputs reflect those of the scanner output image.

DR = X

ROR = 1

These two combinations reset device outputs.

DR = 1

ROR = X

DR = X

ROR = 1

These two combinations reset device outputs.

DR = 1

ROR = X

Outputs remained unchanged.

DR = 0

In this instance, the last

ROR = 0 state switch setting is valid.

Once these outputs are reset, they remain reset regardless of the DR and ROR settings.

DR = X

ROR = 1

These two combinations reset device outputs.

DR = 1

ROR = X

Program DR = 0

ROR = 1

Default values are set automatically. Outputs reflect those of the scanner output image.

DR = 0

ROR = 1

These default values are set automatically. Outputs are reset, unless ROR is changed to 0 on the first scan.

DR = X

ROR = X

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M1 Status File

Description

M1 file words 0 through 47 contain the status of all devices on the scanner’s RIO link. M1 is a read only file; do not write to this file.

Words 0-47 of the M1 file provide the following information:

• Word 0 (M1:e.0) - general communication status (overall device fault and communications attempted)

• Word 2 (M1:e.2) - RIO baud rate status

• Word 3 (M1:e.3) - complementary device starting address status

• Word 4 (M1:e.4) - complementary logical image size status

• Word 5 (M1:e.5) - complementary active device status

• Word 8 (M1:e.8) - primary/normal device starting address status

• Word 9 (M1:e.9) - primary/normal logical image size status

• Word 10 (M1:e.10) - active device status

• Words 12-15 (M1:e.12 -15) - device fault status

• Words 16-31 (M1:e.16-31) - primary/normal device retry counters

• Words 32-47 (M1:e.32-47) - complementary device retry counters

General

Communication Status

- Enable Device Fault

Bit

Word 0, bit 0 - is the Enabled Device Fault status bit. When any enabled device is faulted, this bit is set to 1. A fault may be caused by a communication problem with a remote device.

M1 (Status) File Word 0

Bit Number (decimal)

General Communication Status Word, Word 0

15 x

14 x

13 x

12 x

11 x

10 x

9 x

8 x

7 x

6 x

5 x

4 x

3 x

2 x

M1 File

M1:e.0

Enabled Device

Fault Bit

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General

Communication Status

- Communication

Attempted Bit

Word 0, bit 1 - is the Communications Attempted status bit. When

RIO communication has been attempted with all configured devices, this bit is set to 1. There are no further transitions of this bit until a processor change of state occurs (i.e., Program mode to Run mode or

Test mode, or Test mode to Run mode).

Until this bit is set, all devices in M1 file word 10 (active device status) appear to be inactive. This bit can be used to condition the

Enabled Device Fault bit. If the Communications Attempted bit is 1, the Enabled Device Fault bit is valid.

M1 (Status) File Word 0

Bit Number (decimal)

General Communication Status Word, Word 0

15 x

14 x

13 x

12 x

11 x

10 x

9 x

8 x

7 x

6 x

5 x

4 x

3 x

2 x

M1 File

M1:e.0

Communications

Attempted Status Bit

Enable Device

Fault Bit

RIO Baud Rate Status

Word 2, bits 0 to 1 - displays the RIO communication/baud rate you have set the scanner to via its DIP switch. Writing to word 2 does not change the scanner baud rate.

M1 (Status) File - Word 2

Bit Number (decimal)

RIO Baud Rate, Word 2

15 x

14 x

13 x

12 x

11 x

10 x

9 x

8 x

7 x

6 x

5 x

4 x

3 x

2 x

Baud Rate

As illustrated by the table below, bit 0 = SW1 and bit 1 = SW2.

Bit 1-0

Baud Rate

5736K Baud

115.2K Baud

230.4K Baud

SW 1-2

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Logical Device

Starting Address

Status

Word 8 - provides status/feedback of the logical device starting addresses you configured in word 1 of the G file (primary/normal logical devices). Writing to M1 file word 8 does not alter the contents of the G file.

M1 (Status) File-Word 8

Bit Number (decimal)

Primary Logical Device Address, Word 8

G File-Word 1

Starting Group

M1 File

M1:e.3

Primary Logical Device Address, Word 1

6 4

0 1

2 0

0 0

6 4

RIO Logical Rack 3

Starting Group 2

RIO Logical Rack 2

Starting Group 2

RIO Logical Rack 1

Starting Group 0

RIO Logical Rack 0

Starting Group

RIO Logical Rack 0

Starting Group 0

Word 3 - provides status/feedback of the logical device starting addresses you configured in word 3 of the G file (complementary devices). Writing to M1 file word 3 does not alter the contents of the

G file.

M1 (Status) File-Word 3

Bit Number (decimal)

Complementary Logical Device Address, Word 3

15 14

M1 File

M1:e.3

G File-Word 3

Starting Group

Complementary Logical Device Address, Word 3

6 4

Starting Group

6 4

Starting Group

RIO Logical Rack 11

Starting Group 2

RIO Logical Rack 10

Starting Group 2

RIO Logical Rack 9

Starting Group 2

RIO Logical Rack 8

Starting Group 6

RIO Logical Rack 8

Starting Group 0

Logical Device Image

Size Status

Word 9 - provides status/feedback of the logical device image size you configure in word 2 of the G file (primary/normal devices). A bit set to 1 shows the logical image size of each logical device. Writing to word M1 file word 9 does not alter the contents of the G file.

M1 (Status) File-Word 9

Primary Logical Device Address, Word 9

M1 File

M1:e.3

G File-Word 2

RIO Rack 3

Image Size

Primary Logical Device Address, Word 2

RIO Rack 2

Image Size

RIO Rack 1

Image Size

RIO Rack 0

Image Size

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Scanner Configuration and Programming

Complementary Logical Device Address, Word 4

Word 4 - provides status/feedback of the logical device image size you configure in word 4 of the G file (complementary devices). A bit set to 1 shows the logical image size of each logical device. Writing to word M1 file word 4 does not alter the contents of the G file.

M1 (Status) File-Word 4

M1 File

M1:e.3

Complementary Logical Device Address, Word 4

G File-Word 4

RIO Rack 11

Image size

6 4 2

1 1 1

RIO Rack 10

Image Size

4 2

0 1 1

RIO Rack 9

Image Size

4 2

1 1

RIO Rack 8

Image Size

4 2

1 0 0

Active Device Status

Word 10 - provides active device status for primary/normal devices.

When a RIO device is communicating with the scanner the bit corresponding to the device’s logical starting group is set to 1.

Devices that are inhibited in the M0 file (M0:e.8 - M0:e.11) are represented by a 0. Unless devices are inhibited, not responding to communications, or configured to an incorrect logical rack size, this word is identical to the device configuration (M1:e.8).

M1 (Status) File-Word 10

Bit Number (decimal)

Primary Logical Device Address, Word 8

Primary Logical Image Size, Word 9

Primary Active Device Status, Word 10

15 14

RIO Rack 3

Starting Group

6 4 2

0 0

11 10 9

RIO Rack 2

Starting Group

6 4 2

0 0

7 6 5 4

RIO Rack 1 Starting

Group

6 4 2 0

3 2 1

RIO Rack 0

Starting Group

6 4 2

M1 File

M1:e.8

M1:e.9

M1:e.10

A 0 indicates that the device is inhibited, not responding to communications, or configured to an incorrect logical rack size.

A 1 indicates that the configured device is active.

Word 5 - provides active device status for complementary devices.

When a RIO device is communicating with the scanner the bit corresponding to the device’s logical starting group is set to 1.

Devices that are inhibited in the M0 file are represented by a 0.

Unless devices are inhibited, not responding to communications, or configured to an incorrect logical rack size, this word is identical to the device configuration (M1:e.3).

Important:

When a primary device is inhibited, its complementary device is also inhibited. A complementary device cannot be exclusively inhibited.

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M1 (Status) File-Word 5

Bit Number (decimal)

Primary Logical Device Address, Word 3

Primary Logical Image Size, Word 4

Primary Active Device Status, Word 5

15 14 13

RIO Rack 11

Starting Group

6 4 2

11 10 9

RIO Rack 10

Starting Group

6 4 2

7 6

RIO Rack 9

Starting Group

6 4 2

3 2 1

RIO Rack 8

Starting Group

6 4 2

M1 File

M1:e.3

M1:e.4

M1:e.5

A 0 indicates that the device is inhibited not responding to communications, or configured to an incorrect logical rack size.

A 1 indicates that the configured device is active

Logical Device Fault

Status

Words 12 through 15, bits 0 to 7 - indicate the device fault status for logical racks 0, 1, 2, 3, 8, 9, 10, and 11. Bits 0 through 3 are for primary/normal devices and bits 4 through 7 are for complementary devices. Each bit corresponds to a quarter logical rack location. If a device is not responding to communications, has gone offline, or is configured to an incorrect logical rack size, all bits corresponding to the device are set to 1. This is highlighted in the example below.

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M1 (Status) File Primary/Normal Device Fault Status

Bit Number (decimal)

Primary Device Address, Word 8

Primary Device Size, Word 9

Primary Active Device Status, Word 10

15 14 13

RIO Rack 3

Starting Group

6 4 2

11 10 9

RIO Rack 2

Starting Group

6 4 2

The information contained in words 8, 9, and 10 indicates a 3/4 logical rack device beginning at Logical Rack 3 Logical Group 2 is faulted or configured to an incorrect logical rack size. This device status is confirmed in bits 1, 2, and 3 of Device Fault Status Word 15.

7 6 5

RIO Rack 1

Starting Group

6 4 2

3 2 1

RIO Rack 0

Starting Group

6 4 2

M1 File

M1:e.8

M1:e.9

M1:e.10

Logical Rack 0 Device Fault Status Word 12

Logical Rack 1 Device Fault Status Word 13

Logical Rack 2 Device Fault Status Word 14

Logical Rack 3 Device Fault Status Word 15 x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x

e = slot number of the SLC rack containing the scanner x = not use/defined

M1 File

M1:e.12

M1:e.13

M1:e.14

M1:e.15

M1 (Status) File Complementary Device Fault Status

Bit Number (decimal)

15 14 13 12 11 10 9 8

Primary Device Address, Word 3

Primary Device Size, Word 4

Primary Active Device Status, Word 5

RIO Rack 11

Starting Group

6 4 2

RIO Rack 10

Starting Group

4 2 0

The information contained in word 3, 4, and 5 indicates a 3/4 logical rack device beginning at group 2 is inhibited, faulted, or configured to an incorrect logical rack size. this device is confirmed in bits 5, 6, and 7 of Device Fault Status Word 15.

7 6 5 4

RIO Rack 9 Starting

Group

4 2 0

3 2 1

RIO Rack 8

Starting Group

6 4 2

M1 File

M1:e.3

M1:e.4

M1:e.5

Logical Rack 0 Device Fault Status Word 12

Logical Rack 1 Device Fault Status Word 13

Logical Rack 2 Device Fault Status Word 14

Logical Rack 3 Device Fault Status Word 15 x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x

e = slot number of the SLC rack containing the scanner x = not used/defined

x x x x x x x x x x x x x x x x

M1 File

M1:e.12

M1:e.13

M1:e.14

M1:e.15

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RIO Status Example

The following example illustrates an M1 status file example. It shows a typical M1 file and the G file used to configure the scanner. There are no inhibited devices specified in the M0 file (not shown). Notice that:

• M1:e.8 is an image of word 1 (primary/normal logical device address) of the G file.

• M1:e.3 is an image of word 3 (complementary logical device address) of the G file.

• M1:e.9 is an image/copy of word 2 (primary/normal logical device size) of the G file.

• M1:e.4 is an image/copy of word 4 (complementary logical device size) of the G file.

• The three quarter logical rack device located in logical rack 3

(M1:e.9/13) is not active. The fault is indicated by the Enabled

Device Fault status bit, bit 0, word 0 (M1:e.0/0).

• The three quarter logical rack device located in logical rack 11

(M1:e.4/13) is not active. The fault is indicated by the Enabled

Device Fault status bit, bit 0, word 0 (M1:e.0/0).

Because the device at M1:e.8/13 is faulted, bit 13 of word 10

(M1:e.10/13) is 0. M1:e.15/1 through M1:e.15/3, which correspond to

M1:e.9/13 through M1:e.9/15 are also set to 1, indicating a problem with the device in logical rack 3.

Because the device at M1:e.3/13 is faulted, bit 13 of word 5

(M1:e.5/13) is 0. M1:e.15/5 through M1:e.15/7, which correspond to

M1:e.4/13 through M1:e.4/15 are also set to 1, indicating a problem with the device in logical rack 11.

M1 (Status) File Primary/Normal

Bit Number (decimal)

15 14 13 12

Status Word, Word 0

Baud Rate, Word 2

Primary Device Address, Word 8

Primary Device Size, Word 9

Primary Active Device Status, Word 10

Logical Rack 0 Device Fault Status Word 12

Logical Rack 1 Device Fault Status Word 13

Logical Rack 2 Device Fault Status Word 14

Logical Rack 3 Device Fault Status Word 15 x x x x x x x x x x x x

RIO Logical Rack

0 1 0

1 1 1 0

0 0 x x x x

0 x x x x

11 x x

0 x x x x

10 x x

9 x x

RIO Logical

Rack 2

0 1

0 x x x x

1 x x x x

8 x x

0 x x x x

7 x x

0 x x x x

6 x x

0 x x x x x

RIO Logical

Rack 1

0 0

1 1 1

0 x x x x

5 x

1 x x x x

4 x x

3 x

2 x

M1 File

M1:e.0

M1:e.2

1 x

RIO Logical

Rack 0

0 0

1 0 0

M1:e.3

M1:e.4

M1:e.5

M1:e.12

M1:e.13

M1:e.14

M1:e.15

e = slot number of the SLC rack containing the scanner x = not used/defined

G File

Primary Logical Device Address, Word 1

Primary Logical Image Size, Word 2

RIO Logical Rack 3

Starting Group

6 4 2 0

RIO Logical Rack 2

Starting Group

6 4 2 0

RIO Logical Rack 1

Starting Group

6 4 2 0

RIO Logical Rack 0

Starting Group

6 4 2 0

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Scanner Configuration and Programming

Bit Number (decimal)

Status Word, Word 0

Baud Rate, Word 2

Primary Device Address, Word 3

Primary Device Size, Word 4

M1 (Status) File Complementary

Primary Active Device Status, Word 5

15 x

14 x

13 x x

0 x

RIO Logical

Rack 11

0 1

1 1 1

12 x x

Logical Rack 0 Device Fault Status Word 12

Logical Rack 1 Device Fault Status Word 13

Logical Rack 2 Device Fault Status Word 14

Logical Rack 3 Device Fault Status Word 15 x x x x

11 x

10 x

0 x x x

RIO Logical

Rack 10

0 0

9 x

8 x x

7 x

6 x

5 x

1 x x x

RIO Logical

Rack 9

0 0 0 x

4 x x x x x x x x x x x x x x x x x x x x x x x x x x x x x

0 x x x x

e = slot number of the SLC rack containing the scanner x = not used/defined

3 x

2 x

1 x x 0

RIO Logical

Rack 8

1 0 0 x x x x x x x x

M1 File

M1:e.0

M1:e.2

M1:e.3

M1:e.4

M1:e.5

x x x x

M1:e.12

M1:e.13

M1:e.14

M1:e.15

G File

Complementary Logical Device Address, Word 3

Complementary Logical Image Size, Word 4

RIO Logical Rack 11

Starting Group

6 4 2 0

RIO Logical Rack 10

Starting Group

6 4 2 0

RIO Logical Rack 9

Starting Group

6 4 2 0

RIO Logical Rack 8

Starting Group

6 4 2 0

Important:

Individual quarter logical racks within a device cannot be faulted. Therefore, only the starting logical group of the device needs to be monitored.

RIO Communication Retry Counter (M1:e.16 - 47)

M1 File Status Words 16 through 47 - indicate how many RIO communication retries the scanner makes to each adapter on the RIO link if communication problems occur. Each word (16-47) contains a retry counter for each configured quarter logical rack (words 16-31 are for primary logical racks, 0-3, and 32-47 are for complementary racks, 8-11). Retry counters are useful for troubleshooting communication problems (such as electrical noise or poor communication line connections) between the scanner and any adapters. The scanner clears the retry counters when going from

Program to Run mode, Test to Run mode, and Program to Test mode.

Note that the display (in words M1:e.16 -31) of retry counters corresponds to the bits set in the Primary Logical Device Address -

Word 1 of the G file. Likewise, the display (in words M1:e.32-47) correspond to the bits set in the Complementary Logical Device

Address - Word 3 of the G file.

Important:

Your SLC control program cannot initialize/clear retry counters.

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Scanner Configuration and Programming

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Retry Counter Example for Primary Devices

The scanner’s I/O image tables are configured as shown with M1 status files displaying the corresponding retry counters:

G File Primary

Bit Number

15 14 13

RIO Logical Rack 3

Starting Group

12 11 10 9

RIO Logical Rack 2

Starting Group

Primary Logical Device Address, Word 1

1 0 0 1 0 0 1 0

7 6 5 4

RIO Logical Rack 1

Starting Group

0 0 0 1

3 2 1 0

RIO Logical Rack 0

Starting Group

0 1 0 1

Specifies RIO addresses for primary logical devices

G File Complementary

Bit Number

15 14 13

RIO Logical Rack 11

Starting Group

Complementary Logical Device Address, Word 3

0 0 1 1

12 11 10 9 8

RIO Logical Rack 10

Starting Group

0 0 0 1

7 6 5 4

RIO Logical Rack 9

Starting Group

3 2 1 0

RIO Logical Rack 8

Starting Group

0 0 0 1 0 0 0 1

Specifies RIO addresses for complementary devices.

M1:e.16 - communication retry counter for RIO logical rack 0, group 0

M1:e.17 - not used in this example

M1:e.18 -

communication retry counter for RIO logical rack 0, group 4

M1:e.19 - not used in this example

M1:e.20 - communication retry counter for RIO logical rack 1, group 0

M1:e.21 - not used in this example

M1:e.22 - not used in this example

M1:e.23 - not used in this example

M1:e.24 - not used in this example

M1:e.25 - communication retry counter for RIO logical rack 2, group 2

M1:e.26 - not used in this example

M1:e.27 - not used in this example

M1:e.28 - communication retry counter for RIO logical rack 3, group 0

M1:e.29 - not used in this example

M1:e.30 - not used in this example

M1:e.31 - communication retry counter for RIO logical rack 3, group 6

M1:e.32 - communication retry counter for RIO logical rack 8, group 0

M1:e.33 - not used in this example

M1:e.34 - not used in this example

M1:e.35 - not used in this example

M1:e.36 - communication retry counter for RIO logical rack 9, group 0

M1:e.37 -

not used in this example

M1:e.38 - not used in this example

M1:e.39 - not used in this example

M1:e.40 - communication retry counter for RIO logical rack 10, group 0

M1:e.41 - not used in this example

M1:e.42 - not used in this example

M1:e.43 - not used in this example

M1:e.44 - communication retry counter for RIO logical rack 11, group 0

M1:e.45 - communication retry counter for RIO logical rack 11, group 2

M1:e.46 - not used in this example

M1:e.47 - not used in this example

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Scanner Configuration and Programming

Understanding Slot Addressing

This section provides information about:

• 2-slot addressing

• 1-slot addressing

• 1/2-slot addressing

Understanding slot addressing is critical to most efficiently allocate your scanner’s I/O image files.

Slot addressing refers to how each remote chassis slot is assigned a specific amount of the I/O image. The amount depends on which type of slot addressing you choose at your adapter; 2-slot, 1-slot, and

1/2-slot addressing is available, as shown below:

2-Slot

Addressing

Remote Chassis

Slot 2

Two slots are addressed as one logical group.

Input Image

8 7

Output Image

Slot 1

Slot 2

Slot 1

1-Slot

Addressing

Remote Chassis

One slot is addressed as one logical group.

Input Image

8 7 0

Output Image

Slot 1

1/2-Slot

Addressing

Remote Chassis

One slot is addressed as two logical groups.

Input Image

8 7

Slot 1

7 0

Slot 1

For more information on slot addressing, refer to your ASB module user manual.

Note that slot addressing (e.g., 1/2-, 1-, and 2-slot) may not apply to all types of RIO devices. Refer to each RIO device’s user manual to determine the type of slot addressing required.

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Configuration

Scanner Configuration and Programming

5-87

Your SLC processor can be programmed with an HHT

(Hand-Held

Terminal. Although the configuration steps are similar, they are not identical. Therefore, the following basic steps are provided. For specific instructions, refer to the user manual included with your programming device. For more information on M and G files, refer to

Appendix B.

1. Locate an open slot in your SLC chassis. Remember that you must use an SLC 5/02 or later processor.

2. Assign the scanner to a physical slot in the SLC processor’s chassis by selecting Scanner from the list. If the scanner selection is not available, select OTHER from the I/O

Configuration Screen and enter the Code ID number:

13609.

3. Enter the number of Scanned Input and Output Words using the

Specialty I/O and Advanced Setup menus.

The default value is 32 I/O words. You can specify less than 32 and reduce the processor scan time by transferring only the part of the input and output image that your application requires.

Important:

Do not set either of these values to 0. If you do, the scanner will not work correctly.

4. Using the Specialty I/O Configuration menu, set the M1 and M0 file sizes to 32 words (48 words if using complementary I/O). 32 words is the minimum required for operation. If you do not set the M1 and M0 file sizes to at least 32 words, the programming device does not allow you to access the M files in the SLC control program.

If you are using the block transfer (BT) function, you should set the M1 and M0 file sizes to 3,300. Refer to chapter 5 before completing this selection.

5. Set the G file size to 3 (5 if using complementary I/O) using the

Specialty I/O Configuration menu.

6. Enter your setup information using the Modify G File menu.

Important:

SLC 5/02 processors scan chassis I/O slots left to right starting at slot 1, regardless of the module type. SLC 5/

03 and later processors scan slots with discrete I/O modules first, left to right starting at slot 1, and then slots with specialty modules, left to right starting at slot

1. The SLC 5/03 and SLC 5/04 processors cannot be programmed with the HHT.

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Scanner Configuration and Programming

Publication 1747-6.22

Chapter

Module Control and Status Word

The addresses M0:s.400 through M0:s.3499 and M1:s.3400 through

M1:s.3499 are used for status and control exchange between the SLC

5/0x and the 1747-BSN. This item contains the initial definition for these words. The table below shows the address allocation for these words.

Control Word Description M0 Address

Start End

Reserved

Data Transfer Control Word - DTCW

Data Transfer Handshake Word - DTHW

Reserved

3400

3410

3411

3412

3409

3410

3411

3499

Status Word Description

System Status Word - SSW

Module Status Word - MSW

Switch Assemblies Status Word - SASW

Reserved

Data Transfer Status Word - DTSW

Reserved

Module Status Counters

Reserved

Data Block Counters

Reserved

3400

3401

3402

3403

3410

3411

3420

3427

3430

3446

Start

M1 Address

3400

3401

3402

3409

3410

3419

3426

3429

3445

3499

End

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Module Control and Status Word

System Status Word

M1:s.3400

The System Status Word (SSW) presents a synthesis of the backup system status. The primary objective of this word is to provide a fast way to see if the system is working well. The status words described in the following sections provide additional details about the BSN module and system. The SSW status bits have the following meaning:

HSSL

LSL

Buffer Full

S ystem Ready to Switch Over

Remote I/O Communication

Processor Fault

Primary System

Secondary System

Number of BSN Modules

Reserved

Switchover Diagnostic

• HSSL: High-Speed Serial Link status: This bit is set when the

HSSL is faulted or when it has communication errors in one or more 1747-BSN module in the backup system. The normal state of this bit is OFF;

• LSL: Local Status Link status: This bit is set when the Local

Status Link is not working well in either the local or the remote system. If the system has only one 1747-BSN module in each chassis, the LSL is not be used and is always reset. The normal state of this bit is OFF;

• Buffer Full: This bit is set when the secondary 1747-BSN is receiving a second block of data. This occurs before the reading of the first block by the secondary SLC 5/0x. The normal state of this bit is OFF;

• System Ready to Switchover: This bit is set when the backup system is ready to switchover. It is reset when there is one or more errors occurring in the backup system and the system cannot switchover. The normal state of this bit is ON;

• Remote I/O Link: This bit is set when one or more of the RIO links in the system is faulted or has communication errors. The normal state is OFF;

• Processor Fault: This bit is set when either the local or remote processor is in failure, in Program mode, or in Test mode. The normal state of this bit is OFF;

• Primary System: This bit is set when the local system is in primary state;

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Module Control and Status Word

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• Secondary System: This bit is set when the local system is in the secondary state. If the primary bit is set, the secondary system bit is not set. The reverse is also true. When the secondary bit is set, the primary bit is not set. At powerup and during switchover, these primary and secondary bits could be reset at the same time;

• Number of 1747-BSN Modules: This bit indicates the number of 1747-BSN modules in the system.

• Switchover Diagnostic: This bit is set when a 1747-BSN module tests the functionality of the Remote I/O detector circuit when the processor changes form Run to Program mode. If the test fails, this bit is set until the next power down. In this case the module must be replaced.

Number of 1747-BSN’s System Status Word Bits

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Module Control and Status Word

Module Status Word

The Module Status Word (MSW) shows the status of the 1747-BSN module itself and its counterpart in the remote system. Bits 0 through

7 show the local status while bits 8 through 15 show the remote status. The module status bits have the following meaning:

M1:s.3401

LOCAL MODULE BITS

HSSL

LSL

Buffer Full

DH+ Communication

RIO Communication

Processor Fault

Primary/Secondary System

Reserved

REMOTE MODULE BITS

HSSL

LSL

Buffer Full

DH+ Communication

RIO Communication

Processor Fault

Primary/Secondary System

Reserved

• HSSL: High-Speed Serial Link status: This bit is set when the

HSSL is faulted or has communication errors in the local 1747-

BSN module (bit 0) or in the remote one (bit 8). The normal state of this bit is OFF;

• LSL: Local Status Link status: This bit is set when the Local

Status Link is not working well in the local system (bit 1) or remote system (bit 9). If the system has only one 1747-BSN module in each chassis, then the LSL is not used and this bit is reset. The normal state of this bit is OFF;

• Buffer Full: This bit is set when the secondary 1747-BSN is receiving a second block of data before the reading of the first block by the secondary SLC 5/0x. It could be occurring in the local system (bit 2) or remote system (bit 10);

• DH+ Communication: This bit is set when a problem occurs with the DH+ network in the local (bit 3) or remote (bit 11)

1747-BSN module. The type of problem that may occur is different for primary and secondary systems (as shown below).

The normal state of this bit is OFF):

1. Primary mode: the network is down or the channel is seeing communication errors;

0. Secondary: communication errors to the secondary SLC

5/04;

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Module Control and Status Word

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• RIO Communication: This bit is set when a problem occurs with the RIO link in the local (bit 4) or remote (bit 12) 1747-

BSN module. The type of problem that may occur is different for primary and secondary systems (as shown below). The normal state of this bit is OFF):

1. Primary mode: the channel is faulted or has communication errors;

0. Secondary: no communication could be seen by this module in the RIO link. This indicates that the primary

RIO link is not working or that a problem exists in the

RIO connection to the secondary 1747-BSN module;

• Processor Fault: This bit is set when one of the processors

(SLC 5/0x), either the local (bit 5) or remote (bit 13), is in failure or is in Program or Test mode. The normal state of this bit is

OFF;

• Primary/Secondary System: This bit is set when the local (bit

6) or remote (bit 14) system is in the primary mode, otherwise the system is in the secondary mode. Bits 6 and 14 are never set at the same time. During power-up or switchover time, these bits can be clear at the same time. The normal operation is with one bit set for the primary system and one bit clear for the secondary system.

Transferring Data over the High-Speed Serial

Link (HSSL)

Two M0 file words and one M1 file word are used to control the transfer of data from the primary SLC processor to the secondary

SLC processor. This link should be used to transfer internal processor data that must be kept current in the secondary processor in the event that a switchover takes place, making the secondary processor the primary processor. Actual input data from remote I/O chassis need not be transferred over this link since the secondary BSN allows the secondary processor to receive this data from the remote I/O network in a “listen mode”. Outputs are only controlled by the primary processor.

The three words used to accomplish data transfer over the HSSL are:

1. M0:s.3410: Data Transfer Control Word (DTCW)

This word is used by the primary processor to initiate the transfer of data to the primary BSN. This data is ultimately transferred to the secondary BSN over the HSSL, then to the secondary processor.

2. M1:s.3410: Data Transfer Status Word (DTSW)

This word is used in both the primary system and the secondary system to affect the transfer of data on the HSSL.

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Module Control and Status Word

Data Transfer Control

Word

• Primary System - The word must be monitored by the primary processor because this word is used by the primary

BSN to acknowledge that the BSN has received the data block from the processor and is ready for the next transfer for that particular data block number.

• Secondary System - The word is used by the BSN to let the processor know that a new data block is ready for transfer from the secondary BSN to the secondary processor. The ladder program in the secondary processor must monitor the bits in this word to know when to copy new HSSL data from the BSN to the processor data table.

3. M0:s.3411: Data Transfer Handshake Word (DTHW)

This word is used by the secondary processor to inform the secondary BSN that it has received the latest data block and is ready for the next transfer for that particular data block number.

The Data Transfer Control Word (DTCW) is used to control the data table transfer from primary to the secondary system. Each bit corresponds to a block in the 1747-BSN module.

If the primary SLC 5/0x writes a new block into the primary 1747-

BSN, then one bit corresponding to this block must be set in the

DTCW word to advise the backup module that a new valid block is ready to be transferred to the secondary SLC 5/0x. The figure below shows the meaning of the bits in this word.

M0:s.3410

Block # 1

Block # 2

Block # 3

Block # 4

Block # 5

Block # 6

Block # 7

Block # 8

Block # 9

Block # 10

Block # 11

Block # 12

Block # 13

Block # 14

Block # 15

Block # 16

DTCW Word

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Data Transfer Status

Word

Module Control and Status Word

6-95

The Data Transfer Status Word (DTSW) is used in the data table transfer from primary to the secondary system. Each bit corresponds to a block in the 1747-BSN module.

When the primary SLC 5/0x writes a new block into the primary

1747-BSN and sets the bit corresponding to this block in DTCW, the

BSN module transfers the block to the secondary backup module. The

1747-BSN also sets the corresponding bit in DTSW to advise the

SLC 5/0x that the block has been transferred and the block area is free to transfer a new data block. This bit is held set until the corresponding bit in DTCW is cleared by the primary processors.

When the secondary 1747-BSN receives a new data block from the primary system, it writes the block into the M1 area to be read by the secondary SLC 5/0x and sets its corresponding bit in DTSW to advise that this new block is ready to read. After reading the block, the SLC

5/0x must set the corresponding bit in DTHW. Then the 1747-BSN module clears the bit in DTSW. The following figure shows the meaning of the bits in this word.

M1:s.3410

Block # 1

Block # 2

Block # 3

Block # 4

Block # 5

Block # 6

Block # 7

Block # 8

Block # 9

Block # 10

Block # 11

Block # 12

Block # 13

Block # 14

Block # 15

Block # 16

DTSW Word

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Module Control and Status Word

Data Transfer

Handshake Word

The Data Transfer Handshake Word (DTHW) is used in the data table transfer from primary to the secondary system. Each bit corresponds to a block in the 1747-BSN module.

When the secondary 1747-BSN receives a new block from the primary system, it writes the block to the M1 area to be read by the secondary SLC 5/0x. The secondary 1747-BSN also sets its corresponding bit in DTSW to advise that this new block is ready to read. After reading the block, the SLC 5/0x must set the corresponding handshake bit in DTHW. Then the 1747-BSN module clears the bit in DTSW.

M0:s.3411

Block # 1

Block # 2

Block # 3

Block # 4

Block # 5

Block # 6

Block # 7

Block # 8

Block # 9

Block # 10

Block # 11

Block # 12

Block # 13

Block # 14

Block # 15

Block # 16

DTHW Word

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Module Control and Status Word

6-97

The following ladder program example shows how to monitor the status bits in the System Status Word (SSW) and in the Module Status

Word (MSW) that indicate which processor is in the primary mode and which is in the secondary mode. This information is needed in order to determine whether the local processor needs to execute the primary system or the secondary system HSSL data transfer ladder logic.

File 2 monitors the appropriate SSW and MSW bits and executes subroutine 4 if the local system is in primary mode.

Note:

It is recommended that the M1 and M0 file lengths for the BSN be set to the maximum (5548). There is no memory or speed penalty for creating the maximum buffer size for these files in the BSN modules.

Program File 2

0000

Copy the System Status Word (SSW) and the Module Status Word (MSW) from the BSN module to internal storage words in the SLC processor every program scan. Bits 6 and 7 of the SSW word indicate whether this processor is Primary or Secondary at any given time.

Bits 6 and 14 of the MSW word indicate whether the local or remote system is in the Primary or Secondary mode respectively. Virtual

SSW and MSW words/bits are used to minimize M-file transfers, thereby minimizing their effects on the program scan time.

Copy File

Source #M1:1.3400

Dest

Length

#B3:1

0001

This rung executes subroutine number 3 when the Local System is in the Secondary Mode. Subroutine 3 contains the logic which must be executed to properly transfer HSSL data from the Secondary BSN Module to the Secondary SLC Processor.

Virtual SSW Bit: when = 1, indicates the local system is in the Secondary

Virtual MSW Bit: when = 1, indicates

Mode

B3:1 the Local System is in the Primary Mode

B3:2 the Remote System is in the Primary Mode

B3:2

7 6 14

Jump To Subroutine

SBR File Number U:3

0002

This rung executes subroutine number 4 when the Local System is in the Primary Mode. Subroutine 4 contains the logic which must be executed to properly transfer HSSL data from the Primary SLC Processor to the Primary BSN Module.

Virtual SSW Bit: when = 1, the Local

Virtual MSW Bit: when = 1, indicates

System is in the

Primary Mode

B3:1 the Local System is in the Primary Mode

B3:2 the Remote System is in the Primary Mode

B3:2

6 6 14

Jump To Subroutine

SBR File Number U:4

0003

END

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Module Control and Status Word

Program File 3

(Data Table Status Word) to an internal storage word within the SLC processor, B3:3 in this example.

0000

Virtual & Actual

DTSW Words

Move

Source M1:1.3410

Dest

B3:3

0000000000000000<

0001

This rung copies the "new" Data Block #1 data from the secondary BSN to a file within the secondary processor. When the COPy is complete, the DTHW (Data Table handshake Word) bit for Data Block #1 (B3:4/0 = M0:1.3411/0) must be set to inform the secondary BSN that the secondary processor has received the latest Data Block and is now ready for the next block of data via Data Block #1.

Virtual DTSW Bit for

Data Block #1

B3:3

Copy File

Source #M1:1.3500

Dest

Length

#N12:0

128

0002

Virtual DTHW Bit for

Data Block #1

B3:4

This rung copies the "new" Data Block #2 data from the secondary BSN to a file within the secondary processor. When the COPy is complete, the DTHW (Data Table handshake Word) bit for Data Block #2 (B3:4/1 = M0:1.3411/1) must be set to inform the secondary BSN that the secondary processor has received the latest Data Block and is now ready for the next block of data via Data Block #2.

Virtual DTSW Bit for

Data Block #2

B3:3

Copy File

Source #M1:1.3628

Dest

Length

#N12:128

128

0003

Virtual DTHW Bit for

Data Block #2

B3:4

This rung copies the Virtual DTHW word (B3:4) to the actual DTHW word (M0:1.3411) located in the 1747-BSN module. M-file accesses are interrupts to the processor and using virtual words minimizes M-file accesses and therefore minimizes the effects of these transfers on the ladder program scan time.

Virtual & Actual

DTHW Words

Move

Source B3:4

0000000000000000<

Dest M0:1.3411

0004 END

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Program File 4

0000

The following 6 rungs are meant to be executed only when this processor/BSN is in the Primary Mode. When it is acting as the Primary Processor, this rung copies the DTCW and DTSW words to internal storage words within the SLC processor, B3:5 and B3:6 respectively, for this example.

Virtual & Actual

DTCW Words

Move

Source M0:1.3410

Dest B3:5

0000000000000000<

Virtual & Actual

DTSW Words

Move

Source

Dest

M1:1.3410

B3:6

0000000000000000<

0001

This rung monitors the DTCW and DTSW bits for Data Block #1. When a transfer of data using Data Block #1 is not in progress, copy up to 128 words to the appropriate

M-file location for Data Block #1 in the BSN module.

Virtual DTCW Bit for

Data Block #1

B3:5

Virtual DTSW Bit for

Data Block #1

B3:6

0 0

Copy File

Source

Dest

#N13:0

#M0:1.3500

Length 128

0002

0003

Virtual DTCW Bit for

Data Block #1

B3:7

Unlatch the virtual DTCW bit for Data Block #1 when the comparable virtual DTSW bit is set by the BSN module to indicate that it has received the last data via data Block

#1. when B3:7/0 has been unlatched, the BSN module is ready for the next data transfer via Data Block #1.

Virtual DTSW Bit for

Data Block #1

B3:6

Virtual DTCW Bit for

Data Block #1

B3:7

0 0

This rung monitors the DTCW and DTSW bits for Data Block #2. When a transfer of data using Data Block #2 is not in progress, copy up to 128 words to the appropriate

M-file location for Data Block #2 in the BSN module.

Virtual DTCW Bit for

Data Block #2

B3:5

Virtual DTSW Bit for

Data Block #2

B3:6

1 1

Copy File

Source

Dest

#N13:128

#M0:1.3628

Length 128

0004

0005

Virtual DTCW Bit for

Data Block #2

B3:7

Unlatch the virtual DTCW bit for Data Block #2 when the comparable virtual DTSW bit is set by the BSN module to indicate that it has received the last data via data Block

#2. when B3:7/1 has been unlatched, the BSN module is ready for the next data transfer via Data Block #2.

Virtual DTSW Bit for

Data Block #2

B3:6

Virtual DTCW Bit for

Data Block #2

B3:7

1 1

This rung copies the Virtual DTCW word (B3:7) to the actual DTCW word (M0:1.3410) located in the 1747-BSN module. M-file accesses are interrupts to the processor and using virtual words minimizes M-file accesses and therefore minimizes the effects of these transfers on the ladder program scan time.

Virtual & Actual

DTCW Word

Move

Source B3:7

0000000000000000<

Dest M0:1.3410

0006 END

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Module Control and Status Word

Switch Assemblies

Status Word

The Switch Assemblies Status Word (SASW) shows the switch assemblies configuration status for both the six-position (SW1) and the four-position (SW2) dip switch. Bits 0 through 3 show the fourposition dip switch status, while bits 8 through 13 show the sixposition dip switch status.

M1:s.3402

SW-2.1

SW-2.2

SW-2.3

SW-2.4

Reserved

SW-1.1

SW-1.2

SW-1.3

SW-1.4

SW-1.5

SW-1.6

Reserved

4-pos. dip switch status

6-pos. dip switch status

The six-position dip switch is used to configure the communication channel and other miscellaneous information. The switches have the following definition:

• SW-1.1 and SW-1.2: Define the communication channel baud rate as showed in table 4;

• SW-1.3: when ON means that the channel is configured as DH+.

When OFF means that the channel is configured as RIO;

• SW-1.4: User identification SW. This switch can be used by the customer to differentiate one BSN from its counterpart and help on identifying that a switchover occurred. It is only a user switch; the BSN module doesn’t care about the state of this switch;

• SW-1.5: reserved;

• SW-1.6: Last Module in LSL: The BSN module that the user intends to be the last in the Local Status Link must have this switch ON. All the other BSN modules must have this switch

OFF. If a backup system have only one BSN in each processor chassis, this switch must be ON in this module.

SW-1.1

SW-1.2

Baud Rate (KBaud)

57.6

115.2

230.4

Disabled

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Module Status

Counters

Module Control and Status Word

6-101

The four-position dip switch is used to configure the BSN address in the Local Status Link. The table below shows the meaning of bits 0 through 2 of SASW. Switch SW-2-4 is not used.

SW-2.3

Switch Assemblies Status Word Bits

SW-2.2

SW-2.1

1747-BSN Address

The1747-BSN module counts the changes in the local module’s significant status and indicates the changes in its Module Status

Word. The counters show all the errors and status changes since the last power-up and cannot be cleared by the user without powering down the chassis.

Address

M1:s.3420

M1:s.3421

M1:s.3422

M1:s.3423

M1:s.3424

M1:s.3425

M1:s.3426

Counter

HSSL Error Counter

LSL Error Counter

Buffer Full Counter

Reserved

RIO Comm. Error Counter

Processor Fault Counter

Switchover Counter

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Module Control and Status Word

Data Block Counters

To help verify the functionality of the data transfer application program, the 1747-BSN module has a counter for each data block that can be transferred.

Each time that a block is transferred from the primary SLC 5/0x to the primary 1747-BSN, the data block counter that corresponds to this block is incremented once in the primary 1747-BSN. When the secondary SLC 5/0x reads a block from the secondary 1747-BSN, the corresponding counter is incremented once in the secondary

1747-BSN.

Data Block Counter

M1:s.3438

M1:s.3439

M1:s.3440

M1:s.3441

M1:s.3442

M1:s.3443

M1:s.3444

M1:s.3445

M1:s.3430

M1:s.3431

M1:s.3432

M1:s.3433

M1:s.3434

M1:s.3435

M1:s.3436

M1:s.3437

Address

Block # 9

Block # 10

Block # 11

Block # 12

Block # 13

Block # 14

Block # 15

Block # 16

Block # 1

Block # 2

Block # 3

Block # 4

Block # 5

Block # 6

Block # 7

Block # 8

Publication 1747-6.22

RIO Block Transfer

Theory of Operation

Chapter

RIO Block Transfer

This chapter contains the following information:

• RIO block transfer theory of operation

• RIO block transfer general functional overview

• scanner’s block transfer buffer layout

• detailed operation of RIO block transfer

• RIO block transfer application considerations

• steps for setting up a block transfer

• quick reference for using status and control bits

• block transfer control logic examples

This section provides a conceptual overview of block transfer as it pertains to SLCs, RIO scanners, and remote devices. For specific functionality details, refer to the RIO Block Transfer General

Functional Overview section on page 7-5.

What Is RIO Block Transfer?

RIO Block Transfer is a data transfer mechanism that allows you to control the transfer of up to 64 words of data to or from a remote device over the Allen-Bradley RIO link. A Block Transfer Read

(BTR) is used when a remote device transfers data to the SLC. A

Block Transfer Write (BTW) is used when an SLC processor writes data to a remote device.

The diagrams on the following pages illustrate the concepts of how block transfers occur using an SLC processor, an RIO scanner, and a remote device. The first diagram illustrates the path a block transfer follows. The second and third diagrams illustrate in greater detail the theory of operation of a BTR and a BTW, respectively.

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RIO Block Transfer

Chassis Backplane

SLC

Processor

M Files

RIO Block Transfer Theory of Operation-Path of a Block Transfer

Files

RIO

Scanner

I/O

Image

RIO Link

Refer to the diagrams on the following pages for more details on BTR and BTW sequence of operation.

Block Transfer Write (BTW) data travels from the SLC processor across the chassis backplane via the scanner’s M files. The scanner then sends the data across the RIO link to the adapter of intelligent I/O module.

Block Transfer Read (BTR) data travels from the adapter of intelligent I/O module over the RIO link to the scanner. The chassis backplane then transfers BTR data via the scanner’s M files to the SLC processor.

The SLC control program processes the data once the

SLC receives it from the scanner.

_ _ _ = path of a Block Transfer (BT)

SLC 5/02 processor or above

Adapter or

Intelligent I/O

Module

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SLC

Processor

RIO Block Transfer Theory of Operation-Block Transfer Read (BTR)

In this example, Logical Rack 0, Logical Group 0, Logical Slot 1 is used.

One byte is consumed from the input and output images file for "handshake" purposes.

Chassis Backplane

➀

M0 file

M1 file

Files

1747 RIO

Scanner

I/O

Image

RIO Link

Logical

Rack 0

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 0

Group 1

Word 0

Word 1

Word 2

Word 3

Word 4

Word 5

Word 6

Word 7

Word 8

Word 9

Input Image

Output Image

Logical

Rack 3

Group 7

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Word 23

Word 24

Word 25

Word 26

Word 27

Word 28

Word 29

Word 30

Word 31

_ _ _ = path of the BTR

SLC 5/02 processor or later

Adapter or

Intelligent I/O

Module

Slot 1

Slot 0

Slot 1

Slot 0

The steps below detail a successful Block Transfer Read (BTR):

1. The MO file contains BTR control information which controls

(initiates) the scanner BTR operation. (Refer to the Block

Transfer Buffer Layout section for details on control information.)

2. The SLC control program initiates a block transfer read by commanding the scanner to perform the read operation. The adapter/intelligent I/O module sends BTR data across the RIO link to the RIO scanner.

3. The scanner writes the BTR data to a unique M1 file location that you specify. Also, one byte of the scanner’s I.O image file is used for "handshake" purposes between the scanner and the adapter/intelligent I/O module. Note that the SLC control program must never read of write to this "handshake" image space.

4. Using the M1 file and a COP instruction in the control program the scanner transfers the BTR data to the SLC processor via the chassis backplane. The M1 file also contains BTR status information. (Refer to the Block Transfer Buffer Layout section for details on status information.)

5. The SLC control program processes the BTR information.

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RIO Block Transfer

RIO Block Transfer Theory of Operation-Block Transfer Write (BTW)

In this example, Logical Rack 3, Logical Group 7, Logical Slot 1 is used.

Slot 1

Slot 0

Slot 1

Slot 0

Chassis Backplane

SLC

➀

Processor

M0 file

M1 file

Files

1747 RIO

Scanner

I/O

Image

Logical

Rack 0

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 0

Group 1

Word 0

Word 1

Word 2

Word 3

Word 4

Word 5

Word 6

Word 7

Word 8

Word 9

Logical

Rack 3

Group 7

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Word 23

Word 24

Word 25

Word 26

Word 27

Word 28

Word 29

Word 30

Word 31

Input ImageOutput Image

RIO Link

_ _ _ = path of the BTW

SLC 5/02 processor or later

One byte is consumed from the input and output image file for

"handshake" purposes.

Adapter or

Intelligent I/O

Module

The steps below detail a successful Block Transfer Write (BTW):

1. The user’s control program executes a MOV or COP instruction to the MO file to initiate a BTW. The SLC processor sends

BTW data (via the chassis backplane) to the scanner’s MO block transfer control and write data file. (Refer to the Block Transfer

Buffer Layout section for details on control information.

2. The scanner reads the BTW data and control data from the MO file. One byte of the scanner’s I/O image file is used for handshake purposes. Note that the SLC user program must never read or write to this image space.

3. The M1 file contains BTW status information. Refer to the

Block Transfer Buffer Layout section for details on status information.

4. The RIO scanner transfers BTW information across the RIO link to the adapter.

5. The adapter transfers the BTW information to the appropriate adapter or intelligent I/O module.

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RIO Block Transfer

General Functional

Overview

The RIO scanner performs block transfers through control/status buffers that you allocate in the scanner’s M0 and M1 files. For BTWs, the M0 BT buffer contains BTW control data and BTW data, while a corresponding M1 BT buffer contains only BTW status information.

For BTRs, the M0 BT buffer contains only BTR control data, while a corresponding M1 BT buffer contains BTR status information and

BTR data. Block transfers occur asynchronous to RIO link discrete transfers. Note that block transfers occur as RIO scan time allows – discrete I/O transfers have first priority.

A total of 32 block transfer control/status buffers exist in the M0

(output/control) and the M1 (input/status) files. Block transfer buffers consist of:

• 3 BT control words in an M0 file BT buffer

• 4 BT status words in an M1 file BT buffer

• 64 words of BTW data in an M0 file and 64 words of BTR data in an M1 file. Refer to the diagrams on the following pages.

M0 Control Buffers 1...32

Words

100...109

Words

110...173

Words

100...109

Words

110..173

M0:e.100

3 words for control and 7 reserved

64 words for BT

Write Data

M1:e.100

4 words for status and 6 reserved

64 words for BT

Read Data

Words

3200...3209

Words

3210...3273

M1 Status Buffers 1...32

Words

3200...3209

Words

3210...3273

M0:e.3200

You use an M0 file BT control buffer to initiate a BT. The corresponding M1 file displays the status of the block transfer.

3 words for control and 7 reserved

64 words for BT

Write Data

M1:e.3200

BT buffers reside on 100 word boundaries in the M0/M1 files starting at word 100. For example, BT buffer 1 resides at

M0:e.100 and M1:e.100; BT buffer 2 resides at M0:e200 and

M1:e.200; while BT buffer 16 resides at M0:e.1600 and

M1:e.1600. Note that the "e" in these examples refers to the physical chassis slot number in which the scanner resides.

4 words for status and 6 reserved

64 words for BT

Read Data

All block transfer buffers (M0 and M1) are cleared (set to zero) either when the RIO scanner goes through a power cycle or when the SLC processor commands the scanner to change mode from Program to Test mode, Program to Run mode, or

Test to Run mode.

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RIO Block Transfer

Scanner I/O Image Allocation For Block Transfer

Block transfer operations (BTR and BTW) consume only one byte of the RIO scanner’s I/O image file, independent of what type of I/O slot addressing is used. This one byte image is reserved for communication “handshake” purposes between the remote device

(adapter or intelligent I/O module) and the scanner. SLC control programs must never read/write to these image locations because unpredictable operations may result.

Block transfer operations (BTR and BTW) can be addressed to any logical slot within the RIO scanner’s four logical racks. See the examples below and on the following page.

Examples of BT I/O Image File Allocation

Logical

Rack 0

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 0

Group 1

Logical

Rack 3

Group 7

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Word 23

Word 24

Word 25

Word 26

Word 27

Word 28

Word 29

Word 30

Word 31

Word 0

Word 1

Word 2

Word 3

Word 4

Word 5

Word 6

Word 7

Word 8

Word 9

Input Image Output Image

Logical Slot 0

Logical Slot 1

The minimum portion of the scanner’s image that can be assigned to an adapter is 1/4-logical rack. Each logical device that you assign BT operations (BTR or BTW) consumes one byte from the scanner’s input and output image file. The one byte can come from either the "low" byte

(Logical Slot 0) or the "high" byte

(Logical Slot 1). Logical Slot 1 only applies for 2 slot addressing.

In this example there are two block transfer operations mapped to the scanner’s I/O image. One BT operation is mapped to Logical Rack 0,

Logical Group 4, Logical Slot 1. The other is mapped to Logical Rack 3,

Logical Group 4, Logical Slot 0.

Note that the logical address of you

RIO devices (i.e., adapter and intelligent I/O modules) determine where the block transfer gets mapped.

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RIO Block Transfer

7-109

Example 2

In this example, the remote adapter is configured for 2-slot addressing. It is assigned 1/4-logical rack or the scanner’s I/O image files starting at RIO Logical Rack 3, Logical Group 4. The remote adapter controls four analog modules that are configured for block transfer operations. Note that each module uses both the input and output byte of the logical slot to which it is assigned.

1747-SN RIO Scanner’s I/O Image Files

Logical

Rack 0

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 0

Group 1

Logical

Rack 3

Group 7

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Word 23

Word 24

Word 25

Word 26

Word 27

Word 28

Word 29

Word 30

Word 31

Word 0

Word 1

Word 2

Word 3

Word 4

Word 5

Word 6

Word 7

Word 8

Word 9

Input Image Output Image

# 2

# 4

# 1

# 3

# 2

# 4

# 1

# 3

Adapter

Mod.

I/O

Image

Modules’ "handshake" bytes map to these I/O image addresses.

These are all analog modules that are assigned block transfer operations.

Logical Slot 0

Logical Slot 1

Example 3

In this example, the remote adapter is using 2-slot addressing. It is assigned 1/4-logical rack of the scanner’s I/O image files starting at RIO Logical Rack 3, Logical Group 4. The remote adapter controls two analog devices, which are configured for block transfer operations and two discrete devices (8-point input and 8-point output). Note that each analog module uses both the input and output byte of the logical slot to which it is assigned, while the discrete modules use only the input or output byte.

1747-SN RIO Scanner’s I/O Image Files

Logical

Rack 0

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 0

Group 1

Word 0

Word 1

Word 2

Word 3

Word 4

Word 5

Word 6

Word 7

Word 8

Word 9

Input Image Output Image

Logical

Rack 3

Group 7

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Word 23

Word 24

Word 25

Word 26

Word 27

Word 28

Word 29

Word 30

Word 31 not used

# 4

# 1

# 3

# 2 not used

# 1

# 3

Adapter

Mod.

I/O

Image

Modules’ "handshake" bytes map to these I/O image addresses.

These are all analog modules that are assigned block transfer operations.

These are discrete modules.

Module #2 is an8-point output module and module #4 is an8point input module.

Logical Slot 0

Logical Slot 1

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RIO Block Transfer

Scanner’s Block

Transfer Buffer Layout

This section describes the scanner’s M0 (output/control) and

M1(input/status) block transfer buffers.

M0 File - Block Transfer Output/Control Buffers

There are 32 BT output/control buffers allocated in the M0 file. These buffers contain BTR/BTW control information and BTW output data.

The following explains the layout of BT buffer 1.

Important:

The general layout below of buffer 1 is the same for all

32 M0 BT buffers. The "e" in the examples refers to the physical chassis slot number in which the scanner resides. Remember that buffers start on 100 word boundaries.

M0:e.100 - Contains BTR/BTW control flags that control block transfers. Control flags are explained on the following page.

M0:e.101 - Used to configure BTR/BTW length information (0 to

64). Length is the number of BTR/BTW words read from or written to the end device. If length = 0, then the RIO device informs the SLC processor as to how much data to transfer. The M0/M1 BT buffers cannot overflow because they each reserve 64 words of data area.

Logical

Rack 0

Logical

Rack 3

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 0

Group 1

Group 7

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Word 23

Word 24

Word 25

Word 26

Word 27

Word 28

Word 29

Word 30

Word 31

M0:e.102 - Contains the logical address of the BTR/BTW operation in logical rack, group, and slot number format. The logical rack, group, and slot are combined into one word, which you enter in

decimal form.

M0:e.102 Logical Address Example

Word 0

Word 1

Word 2

Word 3

Word 4

Word 5

Word 6

Word 7

Word 8

Word 9

Input Image Output Image

The "Slot Number" (0 or 1) in M0:e.102 indicates the logical slot number within a logical group. 0 designates the least significant image byte and 1 designates the most significant image byte.

Which Slot Number To Use

When your adapter is configured for 2-slot addressing, 0 is the left slot and 1 is the right slot.

For both 1-slot and 1/2-slot addressing the slot number is always 0.

Logical Slot 0

Low Byte

Logical Slot 1

High Byte

Example M0:e.102 Configurations

Logical Rack 0, Group 0, Slot 0 = 0)Logical

Rack 0, Group 0, Slot 1 = 1

Logical Rack 2, Group 3, Slot 1 = 231

Logical Rack 0, Group 7, Slot 0 = 70

M0:e.103 through M0:e.109 - These words are reserved.

M0:e.110 through M0:e.173 - BTW data Words 0 through 63.

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M0 File BT Control Buffer Layout

Important:

The buffer layout below is the same for all 32 BT buffers. Buffer 1 = M0:e.100... buffer 32 = M0:e.3200.

BT Control Buffer Function

M0 Address where x = buffer # from 1 to

Control Flags - See Control Flag

Definitions table below

M0:e.x00

BT Length - 0 through 64 M0:e.x01

BT Address (logical rack, group, and slot) M0:e.x02

Reserved

BTW Data Locations 0 through 63

M0:e.x03 through M0:e. x09

M0:e.x10 through M0:e.x73

BT Control Flag Definitions

Definition

Control flags where x = buffer # from 1 to

M0:e.x00/0 through M0:e.x00/6 These bits are reserved.

Type of BT operation (1 = BTR and 0 =

BTW)

Block Transfer Timeout (TO) = 1 =

Cancel the BT operation.

These bits are reserved.

Block Transfer Enable (EN) = 1 =

Enable the BT operation.

M0:e.x00/7

M0:e.x00/8

M0:e.x00/9 through M0:e.x00/14

M0:e.x00/15

1. Bit 7 indicates whether the SLC control program is initiating a BTR or a BTW.

2. You set bit 8 (timeout bit - TO) = 1 to cancel a BT. You can cancel a BT operation (by timing out) once the Enabled Waiting (EW) bit sets and before the RIO scanner’s internal four second BT timer times out or the BT completes. Cancelling a BT causes an error (ER) bit to set and an error code to display in the M1 BT buffer. Note that the Timeout (TO) flag must be cleared before initiating a new

BT. (You can initiate a new BT by clearing the EN flag, waiting for the ER flag to clear, and then setting the EN bit.) The RIO scanner ignores a BT request if both TO and EN flags are set at the same time.

3. You set bit 15 = 1 to Enable (EN) a BT operation. You set this bit after you have entered all other control information i.e., bits 7 and 8 in the M0 BT buffer. You clear this bit after either the Done

(DN) or Error (ER) bits are set in the M1 Status file. See the M1 file BT Buffer Layout section for more details on the DN and ER bits.

M1 File - Block Transfer Input/Status Buffers

There are 32 BT status buffers allocated in the M1 file. These buffers indicate the status for all BTR and BTW operations and also contain

BTR input data. Below is the layout of BT buffer 1.

Important:

The layout below is the same for all 32 M1 file BT buffers.

M1:e.100 - Status flags that describe the status of the BTR and BTW operations. Status flags are described in detail on the following page.

M1:e.101 - Status of actual number of BTW words sent or the number of BTR words received.

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RIO Block Transfer

Logical

Rack 0

Logical

Rack 3

M1:e.102 - Contains the logical address you have selected in the

M0:e.102 file in rack, group, and slot number format. The logical rack, group, and slot are combined into one word.

M0:e.102 Logical Address Example

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 0

Group 1

Word 0

Word 1

Word 2

Word 3

Word 4

Word 5

Word 6

Word 7

Word 8

Word 9

Input Image Output Image

Group 7

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Word 23

Word 24

Word 25

Word 26

Word 27

Word 28

Word 29

Word 30

Word 31

The "Slot Number" (0 or 1) in M0:e.102 indicates the logical slot number within a logical group. 0 designates the least significant image byte and 1 designates the most significant image byte.

Which Slot Number To Use

When your adapter is configured for 2-slot addressing, 0 is the left slot and 1 is the right slot.

For both 1-slot and 1/2-slot addressing the slot number is always 0.

Logical Slot 0

Example M0:e.102 Configurations

Low Byte

Logical Slot 1

High Byte

The first

Logical Rack 0, Group 0, Slot 0 = 0

Logical Rack 0, Group 0, Slot 1 = 1

Logical Rack 2, Group 3, Slot 1 = 231

number

(reading from right to left )is

Logical Rack 0, Group 7, Slot 0 = 70

the "Slot

Number."

M1:103 - The BTR/BTW error code. Refer to the M1 File Error

Codes table on the following page.

M1:e.104 through M1:e.109 - These words are reserved.

M1:e.110 through M1:e.173 - BTR data Words 0 through 63.

M1 File - Input/Status BT Buffer Layout (M1:e.100... M1:e.3200)

M1 File - BTR/BTW Error Codes (M1:e.103 ... M1:e.3203)

BT Status Buffer Function

M1 Address where x = buffer # from 1 to 32

M0 Address for

BT buffer 1

Status Flags - Refer to the status flags table on the following page.

Actual Length Status- Number of words that were transferred during

BT.

Logical Address Status - logical rack, group, and slot

Block Transfer error code - Refer to the Error Codes table below.

M1:e.x00

M1:s.e.x01

M1:e.x02

M1:e.x03

M1:e.101

M1:e.102

M1:e.103

Reserved

BTR Data Locations 0 through 63

M1:e.x04 through

M1:e.x09

M1:e.x10 through

M1:e.x73

M1:e.104 through

M1:e.109

M1:e.110 through

M1:e.173

...M0 Address for BT buffer 32

...M1:e.3201

...M1:e.3202

...M1:e.3203

...M1:e.3204 through

M1:e.3209

...M1:e.3210 through

M1:e.3273

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- 10

- 11

- 12

- 0

- 6

- 7

- 8

Error Code

-9

Description

The BT completed successfully.

Illegal BT length requested.

BT communication error occurred when BT request was initiated.

Error in BT protocol.

BT timeout - either the SLC user program cancelled the BT or the scanner’s BT timer timed out. Note that a timeout error occurs if a

BT is attempted at a location that is not configured for BT operation

(e.g., requesting a BT for a location that is an output module).

No RIO channel configured.

Attempted a BT either to a nonconfigured BT Device (i.e., an invalid logical rack, group, or slot), or at a complementary device location where there is no corresponding primary image space allocated.

Attempted a BT to an inhibited device.

M1 File - BTR/BTW Status Flag Definitions (M1:e.100 ... M1:e.3200)

Status Flag

M1:e.100/0 through

M1:e.100/9

These bits are reserved.

Description

M1:e.100/10

M1:e.100/11

M1:e.100/12

M1:e.100/13

M1:e.100/14

M1:e.100/15

Block Transfer Enabled and Waiting for block transfer to start - (EW =

Enable Waiting)

This bit is reserved.

Block Transfer Error - (ER = Error)

Block Transfer Successful - (DN = Done)

Block Transfer Started - (ST = Started)

This bit is reserved.

1. When set to a -1" (with bit 14 set to a -0"), bit 10 indicates that a BT operation is pending. You can program a timer in your SLC control program to cancel a BT prior to bit 14 being set. Note that bit

10 must be set to -1" before your SLC user program can cancel the BT operation.

2. When set to a -1", bit 12 indicates that an error occurred while the BT was being processed.

M1:e.103 contains an error code that is useful in determining the cause of an error. Once this bit is set, the SLC user program can reset the Enable (EN) bit in the M0 BT buffer so that a new BT can occur.

3. When set to a -1", bit 13 indicates the successful completion of a BT operation. If the operation was a BTR, the BT data is available in the M1 BT buffer. Once this bit is set, the SLC user program can reset the Enable (EN) bit in the M0 BT buffer so that a new BT can occur.

4. When set to a -1", bit 14 indicates that a BT operation has started. Once the BT operation starts, an

RIO system 4 second timer begins counting down. You can program a timer in your SLC user program to cancel a Started (bit 14) BT.

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RIO Block Transfer

Detailed Operation of

RIO Block Transfer

You use the 1747-BSN Scanner M0 file BTR/BTW output control buffers to set up and control BT operations. Status information regarding the progress and completion of BTR/BTW operations displays in corresponding M1 file input status buffers.

This section describes step-by-step how the RIO scanner uses M0/M1 files to accomplish block transfer operations. The steps below are based on the following assumptions:

• The size of the M0 and M1 files has already been set to 3,300 words. (You set the M file sizes while in off-line programming mode.)

• No pending BT operation utilizing a particular M0 output/ control and M1 status/control buffer is in progress.

• Both the M0/M1 control/status buffers are completely empty.

Important:

Timing diagrams describing BT control and status flag operation follow this section.

1. You set up a BTR or BTW by filling in control information

(about block transfer length, logical rack, logical group, and logical slot address) in an M0 output/control buffer. If you want to set up a BTW, then you must place your write data in the

BTW data area of the M0 output control buffer. You set up M0 buffer information in an integer file and a COP instruction copies the information into the M0 output control file.

2. Your SLC control program initiates a BTR/BTW operation by filling in the BT control field (M0:e.100/7) of the M0 BT buffer.

This indicates whether a BTR or BTW is initiated (0 = BTW and

1 = BTR). Your SLC control program also sets the EN (Enable) flag (M0:e.100/15) which signals the RIO scanner that a new block transfer operation is to begin.

3. The scanner processes the BTR/BTW when it detects that the

SLC control program has set the EN flag. If the RIO scanner detects any problem at this point (such as invalid BT control field, or unconfigured device) the M1 input status buffer’s error code field fills in and the ER (Error) flag in the status field sets.

If no problems occur, the EW (Enable Waiting) flag and ST

(Start) flag set in the status field. (Note that the ST flag will not set if the scanner is already in the process of block transferring data to a location within the same logical rack. The ST flag sets only after any previous pending BTs to the same logical rack have been completed and the BT request has been scheduled on the RIO link.)

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Your SLC control program can monitor the block transfer by examining the M1 status flags. They indicate when the scanner has started processing (EW and ST flags) the BT and whether the BT operation completed successfully (DN flag) or failed (ER flag). Your SLC control program takes different actions based on these status flags.

4. If the BT completes successfully, the scanner fills in the M1 BT length status field. If it was a BTW operation, the BTR data area of the M1 BT buffer is not updated. If it was a BTR operation, the new BTR input data (based on length) is placed in the BTR data area of the M1 BT buffer and the unused buffer area clears.

The DN status flag then sets to indicate to the SLC control program that the BT operation completed successfully and that the M1 input status buffer has been completely updated.

5. If the BT fails, the length field and BTR data area are not updated (length remains cleared). The error code field indicates the problem type. The ER flag sets to indicate to the SLC control program that the BT operation was unsuccessful.

6. The SLC control program must indicate to the scanner when it is done processing the M1 input/status buffer (because DN or ER was set) so the corresponding M0 output/control buffer can be re-used for another BT operation. The SLC control program indicates that it is through processing when it clears the EN flag.

7. When the RIO scanner detects that the EN flag has been cleared by the SLC control program, it then clears the EW, ST and DN or

ER flags. This ensures that the status flags in the M1 input status buffer are not reflecting the results of the previous BT operation.

Note that the other M1 BT Status buffer fields, such as length, error code, and BTR data are not cleared when the scanner clears the status flags. These fields are only updated when the scanner has processed a BT operation as indicated by the DN or ER flag.

For example, if there was a problem with a BT operation, the error code will remain in the M1 BT buffer until the next BT operation causes it to be changed (cleared if DN is set or an error code if ER is set). Therefore, the SLC control program should precede the examination of the error code field with the ER flag.

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RIO Block Transfer

Control

Block Transfer Timing Diagrams

The following pages contain timing diagrams that illustrate the effects of different control flags on a BT operation.

Successful Block Transfer

M0 Control Information 4

M1 Status Information

Status

Successful Block Transfer Read/Write

This example illustrates a successful BT operation.

1. The SLC control program fills in the M0 BT output/control buffer and sets the enable (EN) flag.

2. The scanner detects that the EN flag is set, validates the control information, puts the BT request on the RIO link successfully, and since no other BTs are pending for the same logical rack, sets the enable waiting (EW) and start (ST) flag in M1 status field.

3. The scanner receives a BT reply (with no errors) from the RIO link device, fills in any requested BTR data, and sets the done

(DN) flag.

4. The SLC control program detects the DN flag, processes the BT data, and clears the enable (EN) flag.

5. The scanner detects that the SLC control program has completed processing (because the EN flag is clear) and clears the EW, ST and DN flags. At this point the SLC control program could initiate another BT operation in the same M0 BT buffer by setting the EN flag.

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Control

RIO Block Transfer

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Block Transfer Failure at Startup

M0 Control Information

M1 Status Information

Block Transfer Failure at Startup

In the above example, the scanner found invalid control information

(e.g., an improper logical address) in the M0 block transfer control buffer.

1. The SLC control program fills in the M0 BT buffer and sets the

EN flag.

2. The scanner detects that the EN flag is set, determines that there is some invalid information in the M0 control buffer, fills in the

M1 BT buffer status error code field, and sets the ER flag.

3. The SLC control program detects the ER flag, examines the M1

BT status buffer error code, and clears the EN flag after processing the error.

4. The scanner detects that the SLC control program has processed the error and clears the ER flag.

Note that in this example the EW and ST flags never set. Also, the

SLC control program must clear the EN flag in order to start a new

BT after the error has been corrected.

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RIO Block Transfer

Block Transfer Failure After Startup of Transmission Across RIO Link

M0 Control Information

4 Control Flag

M1 Status Information

Status Flag

Block Transfer Failure after Startup of Transmission Across the RIO

Link

This example illustrates control and status changes when a BT fails after it starts.

1. The SLC control program fills in the M0 BT output/control buffer and sets the EN flag.

2. The scanner detects the EN flag, validates the M0 information, puts the BT request on the RIO link successfully, and sets the

EW and ST flags in the M1 BT input status buffer.

3. The scanner receives a BT reply (with some error) from the RIO link device, fills in the M1 BT buffer’s error code field, and sets the ER flag.

4. The SLC control program detects the ER flag, examines the M1

BT buffer error code, and clears the EN flag after processing the error.

5. The scanner detects that the SLC control program has processed the reply in the M1 BT buffer and clears the EW, ST and ER flags.

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Control Flag

SLC Control Program Cancelling a Block Transfer Once Transmitted

Across RIO Link

M0 Control Information

M1 Status Information

Status Flag

SLC Control Program Canceling a BT Once Transmitted Across RIO

Link

This example illustrates an SLC control program cancelling a BT operation.

1. In this example, the SLC control program wants a BT timeout value less than the four second default value that the scanner uses. When the SLC control program detects that the ST flag has set, a timer in the SLC control program starts.

2. If the timer expires before the scanner returns a BT response

(DN or ER), then the program sets the TO flag.

3. The scanner fills in the error code field and sets the ER flag. The

SLC control program must still clear the EN flag to complete the

BT operation. Note that because of the asynchronous nature of cancelling a transmission to a device that has a BT in progress, the BT reply may indicate either a successful completion or an error.

4. The SLC control program clears the TO and EN flags. Note that if the SLC control program later attempts to initiate another BT and the TO flag is still set, the scanner ignores the BT request.

5. Finally, the EW, ST and ER bits are reset.

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RIO Block Transfer

Control Flag

SLC Control Program Cancelling a Block Transfer Prior To

Transmission Across RIO Link

M0 Control Information

M1 Status Information

Status Flag

SLC Control Program Canceling a BT Prior to Transmission Across RIO

Link

In this example, the SLC control program cancels a BT that has been pending (EW = 1, ST = 0) for a specific amount of time.

1. When the SLC control program detects that the EW has set, a timer in the SLC control program starts.

2. If the timer expires before the scanner begins transmitting across the RIO link (ST = 1), then the SLC control program sets the TO flag. Note that the cancellation will not occur until all previously scheduled BTs to the same logical rack have been completed

(i.e., when the ST bit would normally have been set).

3. The scanner fills in the error code field and sets the ER flag.

Also, the ER bit is not set until any previously pending BTs to that device have been completed. The SLC control program must clear the EN flag to complete the BT operation. Note that because of the asynchronous nature of cancelling a device that has a BT in progress, the BT reply may indicate either a successful completion or an error.

4. The SLC control program clears the TO and EN flags. Note that if the SLC control program later attempts to initiate another BT and the TO flag is still set, the scanner will ignore the BT request.

5. Finally, the EW, ST (if set) and ER bits are reset.

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Below are points to consider when implementing BT operations:

• The minimum amount of scanner image that can be assigned to a device on the RIO link is 1/4-logical rack in the G file configuration. This allows up to four separate devices per logical rack. Each device could have a maximum of four BTs configured to it. Thus, up to 16 BTRs and/or 16 BTWs could be assigned to each logical rack.

• If a BT device is a 1747-ASB RIO Adapter, then multiple SLC

500 modules (such as analog modules) could be scanned by the

1747-ASB and the data block transferred to the RIO scanner.

Since the RIO network handles one BT request per logical rack at a time, there will be a delay before all devices in the 1747-

ASB rack can be accessed. Therefore you should only perform

BTs as necessary (i.e., “on demand”).

• Inhibiting a device on the RIO network (via control words

M0:e.8...11) precludes that device from block transfer operations. Attempting to initiate a BT to an inhibited device results in an error reply. The scanner cancels a BT that is in progress if it detects that the device is inhibited. Because of the asynchronous nature of inhibiting a device that has a BT in progress, the BT reply may indicate either a successful completion or an error. In either case, the SLC control program must still clear the Enable flag.

• All M0 and M1 BT buffers are cleared (set to all zeros) after a power cycle and when the SLC processor goes from Program to

Run mode, Program to Test mode, or Test to Run mode.

When using complementary I/O, if you configure a complementary device to use more I/O image space than an associated primary device, then block transfers can only be performed to locations in the complementary device that have associated I/O image space in the primary device. For example, if a primary device is 1/2 logical rack and a complementary device is a full logical rack, block transfers can be performed only in the first 1/2 logical rack of the complementary device. Attempting block transfers in the last half of the complementary device results in a BT error (error - 11 - device not configured).

Bit Number Octal

Bit Number Decimal

Primary I/O Image

Logical

Rack 0

Word 0

Word 1

Word 2

Word 3

Word 4

Word 5

Word 6

Word 7

1/2 logical rack configured and usable

1/2 logical rack not configured

Bit Number Octal

Bit Number Decimal

Complementary I/O Image

Logical

Rack 8

Word 0

Word 1

Word 2

Word 3

Word 4

Word 5

Word 6

Word 7

1/2 logical rack configured and usable

1/2 logical rack configured, but not usable for BT since Words

4-7 are not configured for the primary device.

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RIO Block Transfer

Setting Up A Block

Transfer

Quick Reference to

Status and Control

Bits

Follow the steps below to set up your scanner and SLC control program for either BTWs or BTRs.

1. To use the BT functionality, you must increase the size of the M0 and M1 files. The size depends on the number of BT buffers your applications requires. Note that setting the buffers to maximum size (3300) will not affect system performance.

However, addressing M-files in your SLC control program does affect system performance.

2. Set the control flags in M0:e.x00. Where x = block transfer buffer number. See the tables below for read/write settings.

If You Want to Transfer Data:

To the scanner from the adapter

From the scanner to the adapter

Use:

BTR (Block Transfer Read)

BTW (Block Transfer Write)

If You Want to specify a:

BTR (Block Transfer Read)

BTW (Block Transfer Write)

Do this to the M0:e.x00/7 file:

Set the bit to 1 to specify a read operation

Set the bit to 0 to specify a write operation

3. Specify the length of the data you wish to block transfer in word

M0:e.x01. Note that maximum length is 64 words.

4. Specify the device’s logical rack, group, and slot in word

M0:e.x02.

5. Set up your SLC control program to set the EN bit.

The tables below provide a quick reference for block transfer status and control bits. In the tables, x = the block transfer file.

Status Bits

This Bit:

Enable Waiting EW -

M1:e.x00/10

Error ER - M1:e.x00/12

Done DN - M1:e.x00/13

Start ST - M1:e.x00/14

Is Set:

upon the scanner’s first detection of EN being set. The EW bit gets reset when the EN flag resets.

when the scanner detects that the block transfer failed. The

ER bit is reset when the EN flag resets.

at completion of the block transfer, if the data is valid. The

DN bit is reset when the EN flag resets.

when the scanner schedules the BT for the adapter. The data transfers may not start for some time. The ST bit is reset when the EN flag resets.

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Control Bits

This Bit:

Read-Write RW -

M0:e.x00/7

Timeout TO - M0:e.x00/8

Enable EN - M0:e.x00/

Is Set:

by your SLC control program. A 0 indicates a write operation; a 1 indicates a read operation.

if you leave the timeout bit reset, the scanner repeatedly tries to send a block transfer request to an unresponsive module for four seconds before setting the ER bit. If you set the TO bit through your SLC program the scanner attempts to cancel the

BT request.

by your SLC control program to initiate a BT request.

Block Transfer Read

Control Logic Example

The following pages contain generic BTR and BTW control logic examples.

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RIO Block Transfer

Block Transfer Read Control Logic Example

Rung 2:0

Configure the BTR operation type, length and rio address at power-up. Bit b3:100/7 must be set prior to run to indicate a BTR operation.

| |

| BIT CONTROL |

| S:1 +COP---------------+ |

|-+----] [-----+------------------------------------------+COPY FILE |

| 15 |Source #B3:100| |

| |Length 3| |

| +------------------+ |

Rung 2:1

Copy the BTR status area to a binary file which will be used throughout the program. This avoids addressing the M1 file multiple times during each program scan. Each time an instruction containing an M1 file bit, word or file is scanned by the processor, an immediate data transfer to the module occurs and will impact the overall processor scan time.

| SERVICE |

| THE BTR |

| STATUS/ |

| BTR |

| PENDING BTR STATUS |

| B3:5 +COP---------------+ |

|-+----] [-----+------------------------------------------+COPY FILE |

| 0 |Source #M1:1.100| |

| | | +------------------+ |

| | CHECK BTR | |

| | STATUS | |

| | UNTIL DN | |

| | OR ER BIT | |

| | IS OFF | |

| | B3:5 | |

| +----] [-----+ |

Rung 2:2

Unlatch the bit that continues to check the btr status. When a BTR is complete, the done bit is set. The ladder program must then unlatch the enable bit, then wait for the SN module to turn off the done bit before another BTR to the same M-file location can be initiate

This is one complete BTR cycle.

| | | CHECK BTR |

| | | STATUS |

| | VIRTUAL | UNTIL DN |

| | BTR DONE | OR ER BIT |

| | BIT | IS OFF |

| B3:0 B3:5 |

|----]/[-------------------------------------------------------------(U)--------

| 13 1

| | VIRTUAL |

| | BTR ERROR |

| | BIT |

| | B3:0 |

| +----]/[-----+

| 12

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Rung 2:3

When a BTR successfully completes, buffer the BT data and unlatch the BT enable bit. Also, unlatch the BTR pending bit and latch the bit that continues checking the BTR status until the SN module turns off the done bit.

| |

| VIRTUAL |

| BTR DONE |

| BIT BTR DATA |

| B3:0 +COP---------------+ |

|----] [------------------------------------------------+COPY FILE +-+-

| 13 | |Source #M1:1.110| | |

| | +------------------+ | |

| | SERVICE | |

| | THE BTR | |

| | STATUS/ | |

| | BTR | |

| | PENDING | |

| | B3:5 | |

| +----(U)-------------+ |

| | 0 | |

| | | |

| | VIRTUAL | |

| | BT ENABLE | |

| | BIT | |

| | B3:100 | |

| +----(U)-------------+ |

| | 15 | |

| | CHECK BTR | |

| | STATUS | |

| | UNTIL DN | |

| | OR ER BIT | |

| | IS OFF | |

| | B3:5 | |

| +----(L)-------------+ |

Rung 2:4

If a BTR error occurs, unlatch the enable bit and buffer the BT error code. Also, unlatch the BTR pending bit and latch the bit that continues checking the BTR status until the SN module turns off the error bit.

| |

| VIRTUAL |

| BTR ERROR BTR ERROR |

| BIT CODE |

| B3:0 +MOV---------------+ |

|----] [----------------------------------------------+-+MOVE +-+-|

| 12 | |Source B3:3| | |

| | | 0000000000000000| | |

| | | 0000000000000000| | |

| | +------------------+ | |

| | | |

| | SERVICE | |

| | THE BTR | |

| | STATUS/ | |

| | BTR | |

| | PENDING | |

| | B3:5 | |

| +----(U)-------------+ |

| | 0 | |

| | | |

| | VIRTUAL | |

| | BT ENABLE | |

| | BIT | |

| | B3:100 | |

| +----(U)-------------+ |

| | 15 | |

| | CHECK BTR | |

| | STATUS | |

| | UNTIL DN | |

| | OR ER BIT | |

| | IS OFF | |

| | B3:5 | |

| +----(L)-------------+ |

| 1 |

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RIO Block Transfer

Rung 2:5

When user logic initiates a new BTR, latch the enable bit, as long as a BTR is not in progress. Also, latch the BTR pending bit, so the BTR status file will be read by the ladder program.

| BTR |BIT |BIT |BIT PENDING |

| I:2.0 B3:100 B3:0 B3:0 B3:5 |

|----] [--------]/[--------]/[--------]/[-----------------------+----(L)-----+-

| 0 15 13 12 | 0 | |

| | | |

| | VIRTUAL | |

| | BT ENABLE | |

| | BIT | |

| | B3:100 | |

| +----(L)-----+ |

| 15 |

Rung 2:6

Move the virtual control word to the M0 file for the SN module whenever a transition of the BTR enable bit occurs.

| |

| VIRTUAL |

| BT ENABLE |

| BIT |

| B3:100 +MOV---------------+ |

|-+----] [-----+------------------------------------------+MOVE +-|

| | 15 | |Source B3:100| |

| | | | 0000000000000000| |

| | | | *| |

| | | +------------------+ |

| | | |

| | VIRTUAL | |

| | BTR DONE | |

| | BIT | |

| | B3:0 | |

| +----] [-----+ |

| | 13 | |

| | | |

| | VIRTUAL | |

| | BTR ERROR | |

| | BIT | |

| | B3:0 | |

| +----] [-----+ |

| 12 |

Rung 2:7

| |

|-------------------------------------+END+------------------------------------

| |

Block Transfer Write Control Logic Example

Rung 2:0

Configure the BTW length and RIO address at power-up. Also, be sure the block transfer operation bit is a "0" indicating a BTW. All these parameters must be entered prior to placing the processor in the run mode.

| |

| POWER±UP |

| BIT |

| S:1 +COP---------------+ |

|----] [--------------------------------------------------+COPY FILE +-

| 15 |Source #B3:100| |

| |Dest #M0:1.100| |

| |Length 3| |

| +------------------+ |

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Rung 2:1

Copy the BTW status area to a binary file which will be used throughout the program, only when a BTW is pending.

This avoids accessing the M1 file multiple times during each program scan. Each time an instruction containing an

M1 file bit, word or file is scanned by the processor, an immediate data transfer to bit, word or file is scanned by the processor, an immediate data transfer to the module occurs and therefore will impact the processor scan time.

| SERVICE |

| THE BTW |

| STATUS/ |

| BTW |

| PENDING BTW STATUS |

| B3:5 +COP---------------+ |

|-+----] [-----+------------------------------------------+COPY FILE +-|

| | 0 | |Source #M1:1.100| |

| | | +------------------+ |

| | | |

| | CHECK BTW | |

| | STATUS | |

| | UNTIL DONE | |

| | BIT IS OFF | |

| | B3:5 | |

| +----] [-----+ |

| 1 |

Rung 2:2

Unlatch the bit that continues to check the BTW status. when a BTW is complete, the done bit is set. The ladder program must then unlatch the enable bit. Then wait for the SN module to turn off the done bit before another BTW to the same M-file location can be initialized. This is one complete BTW cycle.

| | CHECK BTW |

| VIRTUAL | STATUS |

| BTW DONE | UNTIL DONE |

| BIT | BIT IS OFF |

| B3:0 B3:5 |

|-+----]/[-----+-------------------------------------------------------(U)-----|

| | 13 | 1 |

| | | |

| | VIRTUAL | |

| | BTW ERROR | |

| | BIT | |

| | B3:0 | |

| +----]/[-----+ |

| 12 |

Rung 2:3

When a BTW successfully completes, unlatch the BTW enable bit. Also, unlatch the BTW pending bit and latch the bit that continures checking the BTW status until the SN module turns off the done bit.

| SERVICE |

| THE BTW |

| VIRTUAL STATUS/ |

| BTW DONE BTW |

| BIT PENDING |

| B3:0 B3:5 |

|----] [--------------------------------------------------------+----(U)-----+-|

| 13 | 0 | |

| | | |

| | VIRTUAL | |

| | BTW ENABLE | |

| | BIT | |

| | B3:100 | |

| +----(U)-----+ |

| | 15 | |

| | | |

| | CHECK BTW | |

| | STATUS | |

| | UNTIL DONE | |

| | BIT IS OFF | |

| | B3:5 | |

| +----(L)-----+ |

| 1 |

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RIO Block Transfer

Rung 2:4

If a BTW errors, unlatch the enable bit, the BTW pending bit and buffer the BTW error code. Also, latch the bit that continues checking the BTW status until the SN module turns off the error bit.

| |

| VIRTUAL |

| BTW ERROR BUFFER BTW |

| BIT ERROR CODE |

| B3:0 +MOV---------------+ |

|----] [----------------------------------------------+-+MOVE +-+-|

| 12 | |Source B3:3| | |

| | | 0000000000000000| | |

| | | 0000000000000000| | |

| | +------------------+ | |

| | SERVICE | |

| | THE BTW | |

| | STATUS/ | |

| | BTW | |

| | PENDING | |

| | B3:5 | |

| +----(U)---------------+ |

| | 0 | |

| | | |

| | VIRTUAL | |

| | BTW ENABLE | |

| | BIT | |

| | B3:100 | |

| +----(U)---------------+ |

| | 15 | |

| | | |

| | CHECK BTW | |

| | STATUS | |

| | UNTIL DONE | |

| | BIT IS OFF | |

| | B3:5 | |

| +----(L)---------------+ |

When user logic initiates a new BTW, copy the data to the M0 file data area and latch the virtual BTW enable bit, provided that a BTW is not in progress. Also, latch the BTW pending bit, so the BT status file will be read by the ladder program.

| | | | |

| BTW |BIT |BIT |BIT BTW DATA |

| I:2.0 B3:100 B3:0 B3:0 +COP---------------+ |

|----] [--------]/[--------]/[--------]/[-------------+-+COPY FILE +-+-|

| 0 15 13 12 | |Source #N7:110| | |

| | +------------------+ | |

| | SERVICE | |

| | THE BTW | |

| | STATUS/ | |

| | BTW | |

| | PENDING | |

| | B3:5 | |

| +----(L)---------------+ |

| | 0 | |

| | | |

| | VIRTUAL | |

| | BTW ENABLE | |

| | BIT | |

| | B3:100 | |

| +----(L)---------------+ |

| 15 |

Publication 1747-6.22

RIO Block Transfer

7-129

Rung 2:6

Move the virtual control word to the M0 file for the SN module whenever a transition of the BTW eneble bit occurs.

| |

| VIRTUAL |

| BTW ENABLE |

| BIT |

| B3:100 +MOV---------------+ |

|-+----] [-----+------------------------------------------+MOVE +-|

| | 15 | |Source B3:100| |

| | | | 0000000000000000| |

| | | | *| |

| | | +------------------+ |

| | | |

| | VIRTUAL | |

| | BTW DONE | |

| | BIT | |

| | B3:0 | |

| +----] [-----+ |

| | 13 | |

| | | |

| | VIRTUAL | |

| | BTW ERROR | |

| | BIT | |

| | B3:0 | |

| +----] [-----+ |

| 12 |

|-------------------------------------+END+------------------------------------

| |

Directional Continuous Block Transfer Example

The following rungs demonstrate a directional continuous block transfer. As long as the BTR precondition bit is true, block transfer reads execute continuously. Use the same method for a BTW.

Publication 1747-6.22

7-130

RIO Block Transfer

Rung 2:0

Configure the BTR operation type, length and RIO address at power-up. Bit b3:100/7 must be set prior to going to ru to indicate a BTR operation.

| |

| POWER±UP BTR |

| BIT CONTROL |

| S:1 +COP---------------+ |

|----] [--------------------------------------------------+COPY FILE +-

| 15 |Source #B3:100| |

| |Dest #M0:1.100| |

| |Length 3| |

| +------------------+ |

Rung 2:1

Copy the BTR status area to a binary file which will be used throughout the program. This avoids addressing the

M1 file multiple times during each program scan. Each time an instruction containing an M1 file bit, word or file is scanned by the processor an immediate data transfer to the module occurs and therefore will impact the overall processor scan time.

| |

| BTR |

| PENDING BTR STATUS |

| B3 +COP---------------+ |

|-+----] [-----+------------------------------------------+COPY FILE +-

| | 80 | |Source #M1:1.100| |

| | | +±±±±±±±±±±±±±±±±±±+ |

| | | |

| | CHECK BTR | |

| | STATUS | |

| | B3 | |

| +----] [-----+ |

| 81 |

Rung 2:2

When the error or done bit is set indicating that the BTR completed either unsuccessfully or successfully, the enable bit must be unlatched by the ladder program. The 1747-SN scanner then unlatches the error/done bit to complete the block transfer hand-shake process at this time the "check BTR status" bit must be unlatched to avoid

| | unnecessary M-file accesses.

| VIRTUAL |

| BTR DONE CHECK BTR |

| BIT STATUS |

| B3 B3 |

|-+----]/[-----+-------------------------------------------------------(U)-----

| | 13 | 81 |

| | | |

| | VIRTUAL | |

| | BT ERROR | |

| | BIT | |

| | B3 | |

| +----]/[-----+ |

| 12 |

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RIO Block Transfer

7-131

Rung 2:3

When a BTR successfully completes, buffer the BTR data and unlatch the BTR enable bit. Also, unlatch the

BTR pending bit and latch the bit that continues checking the BTR status until the SN turns off the done bit.

| VIRTUAL

| BTR DONE

| BIT BTR DATA

| B3 +COP---------------+

|----] [----------------------------------------------+-+COPY FILE +-+

| 13 | |Source #M1:1.110| |

| | +------------------+ |

| | |

| | BTR |

| | PENDING |

| | B3 |

| +----(U)---------------+

| | 80 |

| | |

| | VIRTUAL |

| | BTR ENABLE |

| | BIT |

| | B3 |

| +----(U)---------------+

| | 1615 |

| | |

| | CHECK BTR |

| | STATUS |

| | B3 |

| +----(L)---------------+

| 81

Rung 2:4

When a BTR unsuccessfully completes, buffer the error code and unlatch the BTR enable bit and the BTR pending bit. Also, latch the check BTR status bit in order to continue reading the status information from the scanner until it turns the error bit off, completing the handshake process.

| VIRTUAL

| BT ERROR BTR ERROR

| BIT CODE

| B3 +MOV---------------+

|----] [----------------------------------------------+-+MOVE +-+

| 12 | |Source M1:1.103| |

| | | *| |

| | | 0| |

| | +------------------+ |

| | |

| | BTR |

| | PENDING |

| | B3 |

| +----(U)---------------+

| | 80 |

| | |

| | VIRTUAL |

| | BTR ENABLE |

| | BIT |

| | B3 |

| +----(U)---------------+

| | 1615 |

| | |

| | CHECK BTR |

| | STATUS |

| | B3 |

| +----(L)---------------+

| 81

Publication 1747-6.22

7-132

RIO Block Transfer

Rung 2:6

Block transfer reads execute continuously as long as the BTR precondition bit is true.

| | | | |

| BIT |BIT |BIT |BIT PENDING |

| B3 B3 B3 B3 B3 |

|----] [--------]/[--------]/[--------]/[-----------------------+----(L)-----+-|

| 83 1615 13 12 | 80 |

| | |

| | VIRTUAL |

| | BTR ENABLE |

| | BIT |

| | B3 |

| +----(L)-----+

| 1615

Rung 2:7

Move the virtual control word to the M0 file for the SN module while a BTR is in progress, and continue doing so until the enable, done and error bits are all turned off, completing the hand-shake process.

| VIRTUAL BTR

| BTR ENABLE CONTROL

| BIT WORD

| B3 +MOV---------------+

|-+----] [-----+------------------------------------------+MOVE +-

| | 1615 | |Source B3:100|

| | | | 0000000000000000|

| | | | *|

| | | +------------------+

| | |

| | VIRTUAL |

| | BTR DONE |

| | BIT |

| | B3 |

| +----] [-----+

| | 13 |

| | |

| | VIRTUAL |

| | BT ERROR |

| | BIT |

| | B3 |

| +----] [-----+

| 12

|-------------------------------------+END+------------------------------------

Publication 1747-6.22

RIO Block Transfer

7-133

Directional Repeating Block Transfer Example

The following example shows a directional repeating block transfer.

This means that block transfer reads are sent repeatedly, as fast as possible. Use the same method for a BTW.

Rung 2:0

Configure the BTR operation type, length and RIO address at power-up. Bit B3:100/7 must be set prior

| |

| POWER±UP BTR |

| BIT CONTROL |

| S:1 +COP---------------+ |

|----] [--------------------------------------------------+COPY FILE +-

| 15 |Source #B3:100| |

| |Dest #M0:1.100| |

| |Length 3| |

| +------------------+ |

Rung 2:1

| |

| BTR |

| PENDING BTR STATUS |

| B3 +COP---------------+ |

|-+----] [-----+------------------------------------------+COPY FILE +-

| | 80 | |Source #M1:1.100| |

| | | +------------------+ |

| | | |

| | CHECK BTR | |

| | STATUS | |

| | B3 | |

| +----] [-----+ |

| 81 |

Rung 2:2

Unlatch the bit that continues to check the BTR status. When a BTR is complete, the done or error bit is set. The ladder program must then unlatch the enable bit, then wait for the SN module to turn off the done/error bit before

| |

| VIRTUAL |

| BTR DONE CHECK BTR |

| BIT STATUS |

| B3 B3 |

|-+====]/[-----+-------------------------------------------------------(U)-----

| | 13 | 81

| | |

| | VIRTUAL |

| | BT ERROR |

| | BIT |

| | B3 |

| +----]/[-----+

| 12

Publication 1747-6.22

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RIO Block Transfer

Rung 2:3

When a BTR successfully completes, buffer the BTR data and unlatch the BTR enable bit. Also, unlatch the BTR pending bit and latch the bit that continues checking the BT status unil the SN turns off the done bit.

| |

| VIRTUAL |

| BTR DONE |

| BIT BTR DATA |

| B3 +COP---------------+ |

|----] [------------------------------------------------+COPY FILE +-+-

| 13 | |Source #M1:1.110| | |

| | +------------------+ | |

| | | |

| | BTR | |

| | PENDING | |

| | B3 | |

| +----(U)---------------+ |

| | 80 | |

| | | |

| | VIRTUAL | |

| | BTR ENABLE | |

| | BIT | |

| | B3 | |

| +----(U)---------------+ |

| | 1615 | |

| | | |

| | CHECK BTR | |

| | STATUS | |

| | B3 | |

| +----(L)---------------+ |

| 81 |

Rung 2:4

| |

| VIRTUAL |

| BT ERROR |

| BIT |

| B3 +MOV---------------+ |

|----] [------------------------------------------------+MOVE +-+-|

| 12 | |Source M1:1.103| | |

| | | *| | |

| | | 0| | |

| | +------------------+ | |

| | | |

| | BTR | |

| | PENDING | |

| | B3 | |

| +----(U)---------------+ |

| | 80 | |

| | | |

| | VIRTUAL | |

| | BTR ENABLE | |

| | BIT | |

| | B3 | |

| +----(U)---------------+ |

| | 1615 | |

| | | |

| | CHECK BTR | |

| | STATUS | |

| | B3 | |

| +----(L)---------------+ |

| 81 |

Publication 1747-6.22

RIO Block Transfer

7-135

Rung 2:5

Block transfer reads will repeat as fast as possible as long as these rungs are scanned.

| | | |

| VIRTUAL |VIRTUAL |VIRTUAL |

| BTR ENABLE|BTR DONE |BT ERROR BTR |

| BIT |BIT |BIT PENDING |

| B3 B3 B3 B3 |

|----]/[--------]/[--------]/[----------------------------------+----(L)-----+-

| 1615 13 12 | 80 | |

| | | |

| | VIRTUAL | |

| | BTR ENABLE | |

| | BIT | |

| | B3 | |

| +±±±±(L)±±±±±+ |

| 1615 |

Rung 2:6 doing so until the scanner turns the done/error bit off.

| |

| VIRTUAL |

| BTR ENABLE |

| BIT |

| B3 +MOV---------------+ |

|-+----] [-----+------------------------------------------+MOVE +-|

| | 1615 | |Source B3:100| |

| | | | 0000000000000000| |

| | | | *| |

| | | +------------------+ |

| | | |

| | VIRTUAL | |

| | BTR DONE | |

| | BIT | |

| | B3 | |

| +----] [-----+ |

| | 13 | |

| | | |

| | VIRTUAL | |

| | BT ERROR | |

| | BIT | |

| | B3 | |

| +----] [-----+ |

| 12 |

Rung 2:7

| |

|-------------------------------------+END+------------------------------------

| |

Publication 1747-6.22

7-136

RIO Block Transfer

Directional Non-Continuous Block Transfer Example

The following rungs demonstrate a directional non-continuous block transfer. The block transfer executes once for every false-to-true transition of the input. Please note that the input bit I:2.0/0 was chosen randomly for this example and can be any address in your program used to initiate a BTR. Also note that this same method may be used for a BTW.

Rung 2:0

Configure the BTR operation type, length and rio address at power-up. Bit B3:100/7 must be set prior to going to run to indicate a BTR operation.

| |

| POWER±UP BTR |

| BIT CONTROL |

| S:1 +COP---------------+ |

|----] [--------------------------------------------------+COPY FILE +-

| 15 |Source #B3:100| |

| |Dest #M0:1.100| |

| |Length 3| |

Rung 2:1

Copy the BTR status area to a binary file, which is used throughout the program. This avoids addressing the M1 file multiple times during each program scan. Each time an instruction containing an M1 file bit, word or file is scanned b the processor, an immediate data transfer to the module occurs and therefore will impact the overall processor scan time.

| |

| BTR |

| PENDING BTR STATUS |

| B3 +COP---------------+ |

|-+----] [-----+------------------------------------------+COPY FILE +-

| | 80 | |Source #M1:1.100| |

| | | +------------------+ |

| | | |

| | CHECK BTR | |

| | STATUS | |

| | B3 | |

| +----] [-----+ |

| 81 |

Rung 2:2

| |

| VIRTUAL |

| BTR DONE CHECK BTR |

| BIT STATUS |

| B3 B3 |

|-+----]/[-----+-------------------------------------------------------(U)-----|

| | 13 | 81 |

| | | |

| | VIRTUAL | |

| | BTR ERROR | |

| | BIT | |

| | B3 | |

| +----]/[-----+ |

| 12 |

Publication 1747-6.22

RIO Block Transfer

7-137

Rung 2:3

When BTR successfully completes, buffer the BTR data and unlatch the BTR enable bit. Also, unlatch the BTR pending bit and latch the bit that continues checking the BTR status until the SN turns off the done bit.

| |

| VIRTUAL |

| BTR DONE |

| BIT BTR DATA |

| B3 +COP---------------+ |

|----] [------------------------------------------------+COPY FILE +-+-|

| 13 | |Source #M1:1.110| | |

| | +------------------+ | |

| | | |

| | BTR | |

| | PENDING | |

| | B3 | |

| +----(U)---------------+ |

| | 80 | |

| | | |

| | VIRTUAL | |

| | BTR ENABLE | |

| | BIT | |

| | B3 | |

| +----(U)---------------+ |

| | 1615 | |

| | | |

| | CHECK BTR | |

| | STATUS | |

| | B3 | |

| +----(L)---------------+ |

| 81 |

Rung 2:4

| |

| VIRTUAL |

| BTR ERROR |

| BIT |

| B3 +MOV---------------+ |

|----] [------------------------------------------------+MOVE +-+-|

| 12 | |Source M1:1.103| | |

| | | *| | |

| | | 0| | |

| | +------------------+ | |

| | | |

| | BTR | |

| | PENDING | |

| | B3 | |

| +----(U)---------------+ |

| | 80 | |

| | | |

| | VIRTUAL | |

| | BTR ENABLE | |

| | BIT | |

| | B3 | |

| +----(U)---------------+ |

| | 1615 | |

| | | |

| | CHECK BTR | |

| | STATUS | |

| | B3 | |

| +----(L)---------------+ |

| 81 |

Publication 1747-6.22

7-138

RIO Block Transfer

Rung 2:5

Initiate a BTR for each false-to-true transition of the user input.

| USER LOGIC |

| TO |

| INITIATE A |

| BTR |

| I:2 B3 B3 |

|----] [------[OSR]-------------------------------------------------------(L)--|

| 0 82 83 |

Rung 2:6

When user logic initiates a new BTR, latch the enable bit as long as a BTR is not in progress. Also, latch the BTR pending bit so the BTR status file will be read by the ladder program.

| | | |

| VIRTUAL |VIRTUAL |VIRTUAL |

| BTR ENABLE|BTR DONE |BTR ERROR BTR |

| BIT |BIT |BIT PENDING |

| B3 B3 B3 B3 B3 |

|--] [-----]/[--------]/[--------]/[----------------------------+----(L)-------

| 83 1615 13 12 | 80 | |

| | | |

| | VIRTUAL | |

| | BTR ENABLE | |

| | BIT | |

| | B3 | |

| +----(L)-----+ |

| | 1615 | |

| | B3 | |

| +--(U)-------+ |

| 83 |

Rung 2:7

Move the virual control word to the M0 file for the SN module while a BTR is in progress, and continue doing so until

| |

| VIRTUAL BTR |

| BTR ENABLE CONTROL |

| BIT WORD |

| B3 +MOV---------------+ |

|-+----] [-----+------------------------------------------+MOVE +-|

| | 1615 | |Source B3:100| |

| | | | 0000000000000000| |

| | | | *| |

| | | +------------------+ |

| | | |

| | VIRTUAL | |

| | BTR DONE | |

| | BIT | |

| | B3 | |

| +----] [-----+ |

| | 13 | |

| | | |

| | VIRTUAL | |

| | BTR ERROR | |

| | BIT | |

| | B3 | |

| +----] [-----+ |

| 12 |

| |

|-------------------------------------+END+------------------------------------|

| |

Publication 1747-6.22

RIO Block Transfer

7-139

Bidirectional Continuous Block Transfer Example

The following rungs demonstrate a bidirectional continuous block transfer. The BTR and BTW each execute as fast as possible, continuously and independently of one another.

Rung 2:0

Configure the BT operation type, length and RIO address (R, G, S in decimal) at power-up. Bit N7:50/7 must

| | be set to a "1" to indicate a btr and bit N7:53/7 must be a local "0" to indicate a BTW operation.

| |

| POWER±UP BTR |

| BIT CONTROL |

| S:1 +COP---------------+ |

|----] [----------------------------------------------+-+COPY FILE +-+-|

| 15 | |Source #N7:50| | |

| | +------------------+ | |

| | | |

| | BTW | |

| | CONTROL | |

| | +COP---------------+ | |

| +-+COPY FILE +-+ |

| |Source #N7:53| |

| |Dest #M0:1.200| |

| |Length 3| |

| +------------------+ |

Rung 2:1

| |

| BTR |

| PENDING BTR STATUS |

| B3 +COP---------------+ |

|-+----] [-----+------------------------------------------+COPY FILE +-|

| | 0 | |Source #M1:1.100| |

| | | +==================+ |

| | | |

| | CHECK BTR | |

| | STATUS | |

| | B3 | |

| +----] [-----+ |

| 2 |

Rung 2:2

| |

| VIRTUAL |

| BTR DONE CHECK BTR |

| BIT STATUS |

| N7:60 B3 |

|-+----]/[-----+-------------------------------------------------------(U)-----|

| | 13 | 2 |

| | | |

| | VIRTUAL | |

| | BTR ERROR | |

| | BIT | |

| | N7:60 | |

| +----]/[-----+ |

| 12 |

Publication 1747-6.22

7-140

RIO Block Transfer

Rung 2:3

| |

| BTW BTW |

| PENDING STATUS |

| B3 +COP---------------+ |

|-+----] [-----+------------------------------------------+COPY FILE +-|

| | 1 | |Source #M1:1.200| |

| | | +------------------+ |

| | | |

| | CHECK BTW | |

| | STATUS | |

| | B3 | |

| +----] [-----+ |

| 3 |

Rung 2:4

Unlatch the bit that continues to check the BTW status. When a BTW is complete, the done or error bit is set. The ladder program must then unlatch the enable bit, then wait for the SN module to turn off the done/error bit before

| |

| VIRTUAL |

| BTW DONE CHECK BTW |

| BIT STATUS |

| N7:64 B3 |

|-+----]/[-----+-------------------------------------------------------(U)-----|

| | 13 | 3 |

| | | |

| | VIRTUAL | |

| | BTW ERROR | |

| | BIT | |

| | N7:64 | |

| +----]/[-----+ |

| 12 |

Publication 1747-6.22

RIO Block Transfer

7-141

When a BTR successfully completes, buffer the BTR data and unlatch both the BTR virual enable bit and the BTR

| |

| VIRTUAL |

| BTR DONE |

| BIT BTR DATA |

| N7:60 +COP---------------+ |

|----] [------------------------------------------------+COPY FILE +-+-|

| 13 | |Source #M1:1.110| | |

| | +------------------+ | |

| | | |

| | BTR | |

| | PENDING | |

| | B3 | |

| +----(U)---------------+ |

| | 0 | |

| | | |

| | VIRTUAL | |

| | BTR ENABLE | |

| | BIT | |

| | N7:50 | |

| +----(U)---------------+ |

| | 15 | |

| | | |

| | CHECK BTR | |

| | STATUS | |

| | B3 | |

| +----(L)---------------+ |

| 2 |

Rung 2:6

When a BTR unduccessfully completes, buffer the error code and unlatch the BTR enable bit and the BTR pending bit. Also, latch the check BTR status bit in order to continue reading the status information from the scanner until it

| | turns off the error bit, completing the handshake process.

| |

| VIRTUAL |

| BTR ERROR BTR ERROR |

| BIT CODE |

| N7:60 +MOV---------------+ |

|----] [----------------------------------------------+-+MOVE +-+-|

| 12 | |Source M1:1.103| | |

| | | *| | |

| | | 0| | |

| | +------------------+ | |

| | | |

| | BTR | |

| | PENDING | |

| | B3 | |

| +----(U)---------------+ |

| | 0 | |

| | | |

| | VIRTUAL | |

| | BTR ENABLE | |

| | BIT | |

| | N7:50 | |

| +----(U)===============+ |

| | 15 | |

| | | |

| | CHECK BTR | |

| | STATUS | |

| | B3 | |

| +----(L)---------------+ |

| |

Publication 1747-6.22

7-142

RIO Block Transfer

Rung 2:7

When a BTW successfully completes unlatch the BTW enable bit and the BTW pending bit to complete a BTW

| |

| VIRTUAL |

| BTW DONE BTW |

| BIT PENDING |

| N7:64 B3 |

|----] [========================================================+----(U)-----+-|

| 13 | 1 | |

| | | |

| | VIRTUAL | |

| | BTW ENABLE | |

| | BIT | |

| | N7:53 | |

| +----(U)=====+ |

| | 15 | |

| | | |

| | CHECK BTW | |

| | STATUS | |

| | B3 | |

| +----(L)-----+ |

| 3 |

Rung 2:8

When a BTW unsuccessfully completes, buffer the error code and unlatch the BTW enable bit and the BTW pending bit. Also, latch the check BTW status bit in order to continue reading the status information from the

| |

| VIRTUAL |

| BTW ERROR BTW ERROR |

| BIT CODE |

| N7:64 +MOV===============+ |

|----] [----------------------------------------------+-+MOVE +-+-|

| 12 | |Source M1:1.203| | |

| | | *| | |

| | | 0| | |

| | +------------------+ | |

| | | |

| | BTW | |

| | PENDING | |

| | B3 | |

| +----(U)---------------+ |

| | 1 | |

| | | |

| | VIRTUAL | |

| | BTW ENABLE | |

| | BIT | |

| | N7:53 | |

| +----(U)===============+ |

| | 15 | |

| | | |

| | CHECK BTW | |

| | STATUS | |

| | B3 | |

| +----(L)---------------+ |

| 3 |

Publication 1747-6.22

RIO Block Transfer

7-143

Rung 2:9

This rung executes block transfer reads continuously, as fast as possible.

| | | |

| VIRTUAL |VIRTUAL |VIRTUAL |

| BTR ENABLE|BTR DONE |BTR ERROR BTR |

| BIT |BIT |BIT PENDING |

| N7:50 N7:60 N7:60 B3 |

|====]/[========]/[========]/[==================================+----(L)-----+-|

| 15 13 12 | 0 | |

| | | |

| | VIRTUAL | |

| | BTR ENABLE | |

| | BIT | |

| | N7:50 | |

| +±±±±(L)±±±±±+ |

This rung executes block transfer writes continuously, as fast as possible.

| | | |

| VIRTUAL |VIRTUAL |VIRTUAL |

| BTW ENABLE|BTW DONE |BTW ERROR |

| BIT |BIT |BIT BTW DATA |

| N7:53 N7:64 N7:64 +COP===============+ |

|----]/[--------]/[--------]/[--------------------------+COPY FILE +-+-|

| 15 13 12 | |Source #N7:10| | |

| | +------------------+ | |

| | | |

| | VIRTUAL | |

| | BTW ENABLE | |

| | BIT | |

| | N7:53 | |

| +----(L)---------------+ |

| | 15 | |

| | | |

| | BTW | |

| | PENDING | |

| | B3 | |

| +----(L)---------------+ |

| 1 |

Rung 2:11

Move the virtual BTR control word to the M0 file for the SN module while a BTR is in progress, and continue doing so un

| |

| VIRTUAL BTR |

| BTR ENABLE CONTROL |

| BIT BITS |

| N7:50 +MOV---------------+ |

|-+----] [-----+------------------------------------------+MOVE +-|

| | 15 | |Source N7:50| |

| | | | 0| |

| | | | *| |

| | | +================+ |

| | | |

| | VIRTUAL | |

| | BTR DONE | |

| | BIT | |

| | N7:60 | |

| +====] [=====+ |

| | 13 | |

| | | |

| | VIRTUAL | |

| | BTR ERROR | |

| | | |

Publication 1747-6.22

7-144

RIO Block Transfer

Rung 2:12

Move the virtual BTW control word to the M0 file for the SN module while a BTW is in progress, and continue doing so

| |

| VIRTUAL BTW |

| BTW ENABLE CONTROL |

| BIT BITS |

| N7:53 +MO----------------+ |

|-+----] [-----+------------------------------------------+MOVE +-|

| | 15 | |Source N7:53| |

| | | | 0| |

| | | | *| |

| | | +------------------+ |

| | | |

| | VIRTUAL | |

| | BTW DONE | |

| | BIT | |

| | N7:64 | |

| +----] [-----+ |

| | 13 | |

| | | |

| | VIRTUAL | |

| | BTW ERROR | |

| | BIT | |

| | N7:64 | |

| +----] [-----+ |

| 12 |

|-------------------------------------+END+------------------------------------|

| |

Bidirectional Alternating Block Transfer

The following rungs demonstrate a bidirectional alternating block transfer. Using these rungs ensures the block transfer requests are executed in the order in which they are sent to the queue. This example also ensures that the block transfer read and block transfer write alternate. The XIO conditions prevent the BTR and BTW from queueing simultaneously. The block transfers continue as long as the

XIC precondition bit is true.

Rung 2:0

Configure the BT operation type, length, and RIO address (R, G, S in decimal) at power-up. N7:50/7 must be set to a

| |

| POWER±UP BTR |

| BIT CONTROL |

| S:1 +COP---------------+ |

|----] [----------------------------------------------+-+COPY FILE +-+-|

| 15 | |Source #N7:50| | |

| | +------------------+ | |

| | | |

| | BTW | |

| | CONTROL | |

| | +COP---------------+ | |

| +-+COPY FILE +-+ |

| |Source #N7:53| |

| |Dest #M0:1.200| |

| |Length 3| |

| +------------------+ |

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Rung 2:1

Copy the BTR status area to an integer file only when a BTR is in progress. This status data will then be used

| | throughout the program and limit sthe number of M-file accesses.

| |

| BTR |

| PENDING BTR STATUS |

| B3 +COP---------------+ |

|-+----] [-----+------------------------------------------+COPY FILE +-|

| | 0 | |Source #M1:1.100| |

| | | +------------------+ |

| | | |

| | CHECK BTR | |

| | STATUS | |

| | B3 | |

| +----] [-----+ |

| 2 |

Rung 2:2

| |

| VIRTUAL |

| BTR DONE CHECK BTR |

| BIT STATUS |

| N7:60 B3 |

|-+----]/[-----+-------------------------------------------------------(U)-----|

| | 13 | 2 |

| | | |

| | VIRTUAL | |

| | BTR ERROR | |

| | BIT | |

| | N7:60 | |

| +----]/[-----+ |

| 12 |

Rung 2:3

| |

| BTW BTW |

| PENDING STATUS |

| B3 +COP---------------+ |

|-+----] [-----+------------------------------------------+COPY FILE +-|

| | 1 | |Source #M1:1.200| |

| | | +------------------+ |

| | | |

| | CHECK BTW | |

| | STATUS | |

| | B3 | |

| +----] [-----+ |

| 3 |

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Rung 2:4

| |

| VIRTUAL |

| BTW DONE CHECK BTW |

| BIT STATUS |

| N7:64 B3 |

|-+----]/[-----+-------------------------------------------------------(U)-----|

| | 13 | 3 |

| | | |

| | VIRTUAL | |

| | BTW ERROR | |

| | BIT | |

| | N7:64 | |

| +----]/[-----+ |

| 12 |

Rung 2:5

When a BTR successfully completes buffer the BTR data and unlatch both the BTR virtual enable bit and the BTR

| |

| VIRTUAL |

| BTR DONE |

| BIT BTR DATA |

| N7:60 +COP---------------+ |

|----] [----------------------------------------------+-+COPY FILE +-+-|

| 13 | |Source #M1:1.110| | |

| | +------------------+ | |

| | | |

| | BTR | |

| | PENDING | |

| | B3 | |

| +----(U)---------------+ |

| | 0 | |

| | | |

| | VIRTUAL | |

| | BTR ENABLE | |

| | BIT | |

| | N7:50 | |

| +----(U)---------------+ |

| | 15 | |

| | | |

| | CHECK BTR | |

| | STATUS | |

| | B3 | |

| +----(L)---------------+ |

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Rung 2:6

When a BTR unsuccessfully completes, buffer the BTR error code and unlatch the BTR enable bit and the BTR pending bit. Also, latch the check BTR status bit in order to continue reading the status information from the

| |

| VIRTUAL |

| BTR ERROR BTR ERROR |

| BIT CODE |

| N7:60 +MOV---------------+ |

|----] [------------------------------------------------+MOVE +-+-|

| 12 | |Source M1:1.103| | |

| | | *| | |

| | | 0| | |

| | +------------------+ | |

| | | |

| | BTR | |

| | PENDING | |

| | B3 | |

| +----(U)---------------+ |

| | 0 | |

| | | |

| | VIRTUAL | |

| | BTR ENABLE | |

| | BIT | |

| | N7:50 | |

| +----(U)---------------+ |

| | 15 | |

| | | |

| | CHECK BTR | |

| | STATUS | |

| | B3 | |

| +----(L)---------------+ |

| 2 |

Rung 2:7

When a BTW successfully or unsuccessfully completes, unlatch the BTW enable bit and the BTW pending bit to complete a BTW sequence. Also, latch the bit that continues checking the BTW status until the BSN module turns

| |

| VIRTUAL |

| BTW DONE BTW |

| BIT PENDING |

| N7:64 B3 |

|-+----] [-----+--------------------------------------+----(U)---------------+-|

| | 13 | | 1 | |

| | | | | |

| | BIT | | BIT | |

| | N7:64 | | N7:53 | |

| +----] [-----+ +----(U)---------------+ |

| 12 | 15 | |

| | | |

| | CHECK BTW | |

| | STATUS | |

| | B3 | |

| +----(L)---------------+ |

| | 3 | |

| | | |

| | BTW ERROR | |

| | CODE | |

| | +MOV---------------+ | |

| +-+MOVE +-+ |

| |Source M1:1.203| |

| | *| |

| |Dest N7:22| |

| | 0| |

| +------------------+ |

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Rung 2:8

This rung and the newt rung toggles between executing a BTR and a BTW while the user supplied BT precondition bit

(B3:0/11 is used in this example) is true.

| | | | | |

| DITION BIT|BIT |BIT |BIT |BIT PENDING |

| B3 N7:50 N7:53 N7:60 N7:60 B3 |

|----] [--------]/[--------]/[--------]/[--------]/[------------+----(L)-----+-|

| 11 15 15 13 12 | 0 | |

| | | |

| | VIRTUAL | |

| | BTR ENABLE | |

| | BIT | |

| | N7:50 | |

| +----(L)-----+ |

| 15 |

Rung 2:9

| | | | | |

| DITION BIT|BIT |BIT |BIT |BIT BTW DATA |

| B3 N7:50 N7:53 N7:64 N7:64 +COP---------------+ |

|----] [--------]/[--------]/[--------]/[--------]/[|-+-+COPY FILE +-+-|

| 11 15 15 13 12 | |Source #N7:10| | |

| | +------------------+ | |

| | | |

| | VIRTUAL | |

| | BTW ENABLE | |

| | BIT | |

| | N7:53 | |

| +----(L)---------------+ |

| | 15 | |

| | | |

| | BTW | |

| | PENDING | |

| | B3 | |

| +----(L)---------------+ |

| 1 |

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Rung 2:10

Move the virtual BTR control word to the M0 file for the BSN module while a BTR is in progress, and continue

| |

| VIRTUAL BTR |

| BTR ENABLE CONTROL |

| BIT BITS |

| N7:50 +MOV---------------+ |

|-+----] [-----+------------------------------------------+MOVE +-|

| | 15 | |Source N7:50| |

| | | | 0| |

| | | | *| |

| | | +------------------+ |

| | | |

| | VIRTUAL | |

| | BTR DONE | |

| | BIT | |

| | N7:60 | |

| +----] [-----+ |

| | 13 | |

| | | |

| | VIRTUAL | |

| | BTR ERROR | |

| | BIT | |

| | N7:60 | |

| +----] [-----+ |

| 12 |

Rung 2:11

Move the virual BTW control word to the M0 file for te BSN module while a BTW is in progress, and continue

| |

| VIRTUAL BTW |

| BTW ENABLE CONTROL |

| BIT BITS |

| N7:53 +MOV---------------+ |

|-+----] [-----+------------------------------------------+MOVE +-|

| | 15 | |Source N7:53| |

| | | | 0| |

| | | | *| |

| | | +------------------+ |

| | | |

| | VIRTUAL | |

| | BTW DONE | |

| | BIT | |

| | N7:64 | |

| +----] [-----+ |

| | 13 | |

| | | |

| | VIRTUAL | |

| | BTW ERROR | |

| | BIT | |

| | N7:64 | |

| +----] [-----+ |

| 12 |

| |

|-------------------------------------+END+------------------------------------|

| |

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RIO Block Transfer

Bidirectional Alternating Repeating Block Transfer

The following rungs demonstrate a bidirectional alternating repeating block transfer. Using these rungs ensures the block transfer requests are executed in the order in which they are sent to the queue. This example also ensures that the BTR and BTW repeatedly alternate.

The XIO conditions prevent the BTR and BTW from queuing simultaneously. The BTs continue as long as the ladder rungs are scanned.

Rung 2:0

Configure the BT operation type, length and RIO address (R, G, S in decimal) at power-up. Bit N7:50/7 must be set to a

| |

"1" to indicate a BTR and N7:53/7 must be a logical "0" to indicate a BTW operation.

| |

| POWER±UP BTR |

| BIT CONTROL |

| S:1 +COP---------------+ |

|----] [----------------------------------------------+-+COPY FILE +-+-|

| 15 | |Source #N7:50| | |

| | +------------------+ | |

| | | |

| | BTW | |

| | OPERATION | |

| | +COP---------------+ | |

| +-+COPY FILE +-+ |

| |Source #N7:53| |

| |Dest #M0:1.200| |

| |Length 3| |

| +------------------+ |

Rung 2:1

| |

| BTR |

| PENDING BTR STATUS |

| B3 +COP---------------+ |

|-+----] [-----+------------------------------------------+COPY FILE +-|

| | 0 | |Source #M1:1.100| |

| | | +------------------+ |

| | | |

| | CHECK BTR | |

| | STATUS | |

| | B3 | |

| +----] [-----+ |

| 2 |

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7-151

Rung 2:2

Unlatch the bit that continues to check the BTR status. When a BTR is complete, the done or error bit is set. Th ladder program must then unlatch the enable bit, then wait for the BSN module to turn off the done/error bit befor

| | another BTR to the same M-file location can be initiated. This is one complete BTR cycle.

| VIRTUAL |

| BTR DONE CHECK BTR |

| BIT STATUS |

| N7:60 B3 |

|-+----]/[-----+-------------------------------------------------------(U)-----|

| | 13 | 2 |

| | | |

| | BTR ERROR | |

| | BIT | |

| | N7:60 | |

| +----]/[-----+ |

| 12 |

Rung 2:3

| |

| BTW BTW |

| PENDING STATUS |

| B3 +COP---------------+ |

|-+----] [-----+------------------------------------------+COPY FILE +-|

| | 1 | |Source #M1:1.200| |

| | | -+------------------+ |

| | | |

| | CHECK BTW | |

| | STATUS | |

| | B3 | |

| +----] [-----+ |

| 3 |

Rung 2:4

Unlatch the bit that continues to check the BTW status. When a BTW is complete, the done or error bit is set. T ladder program must then unlatch the enable bit, then wait for the BSN module to turn off the done/error bit befo

| |

| VIRTUAL |

| BTW DONE CHECK BTW |

| BIT STATUS |

| N7:64 B3 |

|-+----]/[-----+-------------------------------------------------------(U)-----|

| | 13 | 3 |

| | | |

| | VIRTUAL | |

| | BTW ERROR | |

| | BIT | |

| | N7:64 | |

| +----]/[-----+ |

| 12 |

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Rung 2:5

When a BTR successfully completes, buffer the BTR data and unlatch both the BTR virtual enable bit and the BTR

| |

| VIRTUAL |

| BTR DONE |

| BIT BTR DATA |

| N7:60 +COP---------------+ |

|----] [----------------------------------------------+-+COPY FILE +-+-|

| 13 | |Source #M1:1.110| | |

| | +------------------+ | |

| | | |

| | BTR | |

| | PENDING | |

| | B3 | |

| +----(U)---------------+ |

| | 0 | |

| | | |

| | VIRTUAL | |

| | BTR ENABLE | |

| | BIT | |

| | N7:50 | |

| +----(U)---------------+ |

| | 15 | |

| | | |

| | CHECK BTR | |

| | STATUS | |

| | B3 | |

| +----(L)---------------+ |

| 2 |

Rung 2:6

| | turns the error bit off, completing the handshake process.

| |

| BTR ERROR |

| BIT |

| N7:60 +MOV---------------+ |

|----] [----------------------------------------------+-+MOVE +-+-|

| 12 | |Source M1:1.103| | |

| | | *| | |

| | | 0| | |

| | +------------------+ | |

| | | |

| | BTR | |

| | PENDING | |

| | B3 | |

| +----(U)---------------+ |

| | 0 | |

| | | |

| | VIRTUAL | |

| | BTR ENABLE | |

| | BIT | |

| | N7:50 | |

| +----(U)---------------+ |

| | 15 | |

| | | |

| | CHECK BTR | |

| | STATUS | |

| | B3 | |

| +----(L)---------------+ |

| 2 |

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Rung 2:7

| | the done/error bit off. In addition, buffer the BTW error code in case an error ocurs.

| VIRTUAL |

| BTW DONE BTW |

| BIT PENDING |

| N7:64 B3 |

|-+----] [-----+--------------------------------------+----(U)---------------+-|

| | 13 | | 1 | |

| | | | | |

| | BIT | | BIT | |

| | N7:64 | | N7:53 | |

| +----] [-----+ +----(U)---------------+ |

| 12 | 15 | |

| | | |

| | CHECK BTW | |

| | STATUS | |

| | B3 | |

| +----(L)---------------+ |

| | 3 | |

| | | |

| | BTW ERROR | |

| | CODE | |

| | +MOV---------------+ | |

| +-+MOVE +-+ |

| |Source M1:1.203| |

| | *| |

| |Dest N7:22| |

| | 0| |

This rung and the next rung toggles between executing a BTR and a BTW.

| | | | |

| BIT |BIT |BIT |BIT PENDING |

| N7:50 N7:53 N7:60 N7:60 B3 |

|----]/[--------]/[--------]/[--------]/[-----------------------+----(L)-----+-|

| 15 15 13 12 | 0 | |

| | | |

| +++ +++|

| | | |

| | VIRTUAL | |

| | BTR ENABLE | |

| | BIT | |

| | N7:50 | |

| +----(L)-----+ |

| 15 |

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Rung 2:9

| | | | |

| BIT |BIT |BIT |BIT BTW DATA |

| N7:50 N7:53 N7:64 N7:64 +COP--------------+ |

|----]/[--------]/[--------]/[--------]/[-------------+-+COPY FILE +-+-|

| 15 15 13 12 | |Source #N7:10| | |

| | +------------------+ | |

| | | |

| | VIRTUAL | |

| | BTW ENABLE | |

| | BIT | |

| | N7:53 | |

| +----(L)---------------+ |

| | 15 | |

| | | |

| | BTW | |

| | PENDING | |

| | B3 | |

| +----(L)---------------+ |

| 1 |

Rung 2:10

Move the virtual BTR control word to the M0 file for the BSN module while a BTR is in progress, and continue

| |

| VIRTUAL BTR |

| BTR ENABLE CONTROL |

| BIT WORD |

| N7:50 +MOV---------------+ |

|-+----] [-----+------------------------------------------+MOVE +-|

| | 15 | |Source N7:50| |

| | | | 0| |

| | | | *| |

| | | +------------------+ |

| | | |

| | VIRTUAL | |

| | BTR DONE | |

| | BIT | |

| | N7:60 | |

| +----] [-----+ |

| | 13 | |

| | | |

| | BTR ERROR | |

| | BIT | |

| | N7:60 | |

| +----] [-----+ |

| 12 |

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Rung 2:11

Move the virtual BTW control word to the M0 file for the BSN module while a BTR is in progress, and continue doing so until the enable, done and erroer bits are all turned off, completing the handshake

| | process.

| |

| VIRTUAL BTW |

| BTW ENABLE CONTROL |

| BIT WORD |

| N7:53 +MOV---------------+ |

|-+----] [-----+------------------------------------------+MOVE +-|

| | 15 | |Source N7:53| |

| | | | 0| |

| | | | *| |

| | | +------------------+ |

| | | |

| | VIRTUAL | |

| | BTW DONE | |

| | BIT | |

| | N7:64 | |

| +----] [-----+ |

| | 13 | |

| | | |

| | VIRTUAL | |

| | BTW ERROR | |

| | BIT | |

| | N7:64 | |

| +----] [-----+ |

Rung

| |

|-------------------------------------+END+------------------------------------|

| |

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Chapter

Switchover Considerations

When planning programs for the SLC 500 backup system, you must first consider that the program scans of the two processors are not synchronized. This means that the program in the primary processor is not executing the exact same instruction at the same time as the program in the secondary processor. In addition, you must consider:

• timing

• divergence

• I/O forces

• Data Highway Plus switching

• remote I/O switching

• special sections of the data table

• data integrity

This chapter describes the switchover considerations listed above, as well as switchover diagnostic. It also describes how to detect a possible fault in the secondary module in order to avoid switchover problems in the backup system.

Timing Requirements

Switchover from one processor to another takes less than 50 ms.

Note:

Total switchover time is a factor of the 1747-BSN module delay and one program scan of the secondary processor. The time required for one program scan is added because the secondary processor technically has not assumed control until it has completed one scan of its program and remote I/O after a switchover.

When a failure occurs in the primary system, the remote outputs remain in the state set by the primary processor prior to switchover. while the secondary processor assumes control of the process.

Important:

You must program the backup system to account for the following time requirements:

• input signal update time

• time-out on remote I/O link

• data table transfer time over the HSSL

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Switchover Considerations

Input Signal Update Time

It is possible for the secondary processor to read different input conditions immediately after the switchover. To avoid a sudden change in the outputs during switchover, all of the input signals must be present for an amount of time equal to the sum of the following:

• program scan

• I/O scan

• input module delay

• 1747-BSN switchover time

If these conditions are not met, outputs may be assigned different states in the two processors. This can cause a sudden change of operation when switchover occurs.

Time-out on Remote I/O Link

The remote I/O chassis are updated one at a time. The total remote

I/O update is 10 ms per chassis (typical) at 57.6K baud.

To keep the I/O chassis from faulting and losing control of the I/O, the switchover in the remote I/O link is accomplished in less than 50 ms. (The remote I/O link switchover starts when the remote I/O relays in the primary 1747-BSN module open and ends when the remote I/O relays in the secondary 1747-BSN module close.)

This switchover time is less than the 100 ms for the remote I/O adapter watchdog timeout. This permits continuous control of the I/O from the backup system processors.

Data Table Transfer Time on HSSL

Data table transfer time refers to the amount of time it takes to transfer critical data from the primary system to the secondary system. This time is dependent on the amount of data to be sent between the two systems, the number of remote I/O chassis, and the number of remote I/O block transfers that are being executed.

The 1747-BSN module is capable of transferring up to 100K Word per second (10 msec per K Word). This data rate is 2M bits/second.

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Divergence

Forcing I/O

Switchover Considerations

8-159

The synchronization of program execution in both processors limits divergence between the two systems by ensuring that the resulting output data in both processors is always identical.

Because the program scans of the processors are not synchronized, it is possible that the two separate systems read the same input at different times. Eventually, different input values are read, thus different decisions are made and the internal states of the two systems diverge. If the two systems diverge, the secondary system generates a

“bump” when it takes control over the process.The “bump” time is a function of how fast the inputs of the machine or the process are changing, as well the amount of data to send between the primary and secondary units.

One possible method to avoid or reduce the bump is the “loosely synchronized backup” approach. This method requires special user programming techniques. With this approach, primary and the secondary SLC 5/0x execute the same program and are synchronized at a waiting point once per program scan.

To limit divergence, we recommend that the primary and secondary processors execute the same programs.

Backup communication functions provided by the SLC 500 backup system do not transfer the force tables from the primary to the secondary processors. Therefore, if the SLC 500 backup system has forces set in the primary processor, the forces do not transfer to the secondary processor. For this situation, if a switchover occurs, the secondary processor becomes active, but the forces set in the original primary processor are not carried over.

ATTENTION: Set the forces in the secondary processor first. Then set the forces in the primary processor. Likewise, when removing forces, remove forces in the secondary processor before removing the forces in the primary processor. If a switchover occurs and forces were not set in the secondary processor first, the secondary processor does not recognize the forcedon input or output.

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Switchover Considerations

Data Highway Plus

Switching

The user can aggregate a 1747-BSN with the communication channel configured as DH+ network to the system. In this situation, both primary and secondary processors must be set to the same node address. During normal operation, the other equipment in the DH+ network recognize the primary processor in its real node address and the secondary processor in the node address which follows.

When a switchover occurs, the new primary SLC 5/04 assumes its real node address in the DH+ network and the new secondary processor assumes the next node address.

The DH+ smart switch is designed to provide remote programming capability for the secondary processor with the following limitations:

• The secondary SLC 5/04 can be accessed only by one station in the primary link each time. If more than one station tries to access the secondary SLC 5/04 at the same time, the communication performance with this node is degraded significantly.

• The secondary SLC 5/04 only communicates with the secondary

1747-BSN. If a third device is connected to this link, it will not work properly.

• The secondary SLC 5/04 only answers to commands. It cannot start a MSG instruction.

• The primary SLC 5/04 cannot send messages through DH+ to the secondary SLC 5/04.

The secondary processor can be programmed through an access-point address which corresponds to the processor node address plus one

(n+1). The secondary processor becomes part of the link only after a switchover. If the real node address is 5, the primary is the node 5 and the secondary is node 6. If the real node address is 77, the primary is node 77 and the secondary is node 0.

It is possible that the primary processor could have possession of the token during a switchover from the primary to the secondary processor. In this case, the token could be lost even though passage of the token from one station to the next is done as quickly as possible.

If the token is lost, all the stations on the link have an internal watchdog timeout (250 ms) and the nodes assume the token is lost.

The other stations on the link initiate a token recovery procedure which includes:

• recreating the active node table

• rebuilding the link, including the new primary processor

• ensuring that one node gains control of the link

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If the new primary is:

Polling the link

Listening to the link

During this time, while the stations reconstruct the link, communication is interrupted. The length of the interruption depends on the number of stations involved in the link and the number of messages received and/or transmitted. This time is typically less than

50 ms per station.

However, while the link is rebuilding, messages can collide, increasing the amount of time needed to reconstruct the link. As a result, on a typical DH+ link with 6 - 10 stations, the impact on the link due to switchover could be the loss of communication for as much as 1 - 3 seconds.

DH+ switching occurs whenever there is a transfer of control from the primary to the secondary processor. The switchover could result from a power failure or because of other system failures. The table below shows what can happen to the link if the token is lost.

Important:

Note that when a transfer of control from the primary to the secondary processor occurs, the processor that is now primary has the node address of n on the DH+ link.

The processor that is now secondary has the node address of n +1.

the following could occur

Message packet from another station disrupted

Reply packet disrupted

Token pass packet disrupted

New primary processor takes the token

causing this result

The source station turns on error bit in its MSG instruction You provide programming at the source station to regain synchronization with the receiving station. You can do this by monitoring the message instruction error bit as a condition for retransmitting the message.

Same as above

The DH+ link times out and must rebuild. (250ms watchdog timeout)

+ (50 ms x number of stations on the link).

The new primary processor has nothing in its active node table. The

DH+ link times out and must rebuild. (250 ms watchdog timeout) +

(50 ms x number of stations on the link).

New primary processor receives a message from another station

The link continues working normally.

Important:

In the recommended configuration, set both SLC 500 processors to the same station address. The backup modules permit only one of the two processors to be connected to the DH+ at a time. In this configuration, remote PLC processors and operator stations communicate to the processor that currently has primary status. Note that the secondary processor can also be accessed through the primary SLC 500 processor node address plus one (n+1).

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Switchover Considerations

Remote I/O Switching

The communications protocol for the remote I/O link is a masterslave half-duplex type. This means that the master station (processor) sends a command message addressed to a slave (remote I/O adapter), and the slave responds with a reply message addressed to the master.

This is also called two-way alternating communication.

When the communication channel is configured as RIO, the primary

1747-BSN emulates a Series B 1747-SN module with all the features that it provides to the user. Additionally, the secondary 1747-BSN

“spies” on the RIO link to acquire all the input data and use it to emulate the 1747-SN functionality to the secondary SLC 5/0x.

In the secondary system, the 1747-BSN simulates the entire scanner operation to the secondary SLC 5/04 with the following characteristics:

• Real discrete input data is acquired by the secondary BSN from the RIO network and transferred to the secondary SLC 5/04 through the input (I) file.

• Real BTR input data is acquired by the secondary BSN from the

RIO network and transferred to the secondary SLC 5/04 through the M1 file. All the timing necessary for doing a BTR command in the SLC 5/04 is simulated by the secondary BSN.

• The discrete output data sent by the secondary SLC 5/04 through the output (O) file is stored in the output image table for using in case of a switchover.

• The BTW output data sent by the secondary SLC 5/04 through the M0 file is stored into the secondary BSN and all the timing for the BTW operation is simulated by the secondary BSN.

• In case of RIO communication errors seen by the BSN in the primary system (remote rack errors, BTR or BTW errors, etc.), the secondary BSN simulates the same errors for the secondary

SLC 5/04. This simulation is done in order to assure that the secondary SLC 5/04 knows the real status of the remote devices.

• If a switchover occurs, all the input and output data inside the

BSN is ready for the operation as the new primary scanner.

When the backup system is operating properly, the relays of the primary 1747-BSN are closed and the relays of the secondary

1747-BSN are open. Should a failure occur in the primary system, the relays of the primary 1747-BSN module open and the relays in the secondary 1747-BSN module close.

Important:

The smart-switch interface communicates with the secondary processor only when the 1747-BSN module belongs to the secondary system. When the module is primary, the smart switch only monitors the remote I/O link to obtain input/output data.

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The smart switch interface also includes a carrier-detect circuit to monitor the activity of the remote I/O link. The purpose of this circuit is to detect an idle remote I/O link before the secondary relays are closed. This guarantees that the former primary system was really disconnected from the link and the remote adapters have completed their response to the last poll from the primary scanner.

In addition, in the event of an HSSL break, the carrier-detect circuit prevents the secondary system from taking control of the link along with the primary system. The figure below shows the block diagram of the remote I/O switch.

1747-BSN

HSSL link to primary

1747-BSN

Copy of remote

I/O data including block transfers

Remote I/O link

Smart-switch interface

Secondary processor

I/O scanner/adaptor

Carrier-defect circuit

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Switchover Considerations

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Chapter Objectives

Getting Started

Chapter

Programming Techniques

Read this chapter to familiarize yourself with techniques used to program your SLC 500 backup system.

In this chapter we describe:

• how to get started with a program to transfer data table values

• two methods you can use to program the SLC 500 backup system to transfer data table values

• the behavior of specific instructions when used in your application program, and give you suggestions for dealing with these instructions.

The 1747-BSN modules control switchover and transfer remote I/O data without additional programming. However, if you want to transfer data table values from the primary to the secondary processor, you must provide a ladder program. The following figure shows the minimum ladder programming you must provide to transfer 2 Kwords of the data table between the two 1747-BSN modules, and to provide 1747-BSN module status. This program constantly transfers data as fast as possible. 2K words is the maximum per BSN module on the HSSL. With no local I/O, a 5/02 or later processor supports up to 8 BSN modules for a maximum of 16K words of retentive data transfer from primary processor to secondary processor. Refer to the following section, Data Transfer Schemes, for alternative approaches. You need to put this program in both processors.

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Programming Techniques

Program File 2

0000

Copy the System Status Word (SSW) and the Module Status Word (MSW) from the BSN module to internal storage words in the SLC processor every program scan. Bits 6 and

7 of the SSW word indicate whether this processor is Primary or Secondary at any given time. Bits 6 and 14 of the MSW word indicate whether the local or remote system is in the Primary or secondary Mode respectively. Virtual SSW and MSW words/bits are used to minimize M-file transfers, thereby minimizes their effects on the program scan time.

Copy File

Source #M1:1.3400

Dest

Length

#B3:1

0001

Virtual SSW Bit: when = 1, indicates the local system is in the Secondary

Virtual MSW Bit: when = 1, indicates

Mode

B3:1 the Local System is in the Primary Mode

B3:2

Virtual MSW Bit: when = 1, indicates the Remote System is in the Primary Mode

B3:2

7 6 14

Jump To Subroutine

SBR File Number U:3

0002

Virtual SSW Bit: when = 1, the Local

Virtual MSW Bit: when = 1, indicates

System is in the

Primary Mode

B3:1 the Local System is in the Primary Mode

B3:2 the Remote System is in the Primary Mode

B3:2

Jump To Subroutine

6 6 14 SBR File Number U:4

0003

END

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Program File 3

0000

The following rungs are meant to be executed only when this processor/BSN is in the Backup Mode. When it is acting as the Bac kup Processor, this rung copies the DTSW

(Data Table Status Word) to an internal storage word within the SLC processor, B3:3 in this example.

Virtual & Actual

DTSW Words

Move

Source M1:1.3410

Dest B3:3

0000000000000000<

0001

Virtual DTSW Bit for

Data Block #1

B3:3

Copy File

Source #M1:1.3500

Dest

Length

#N12:0

128

0002

Virtual DTHW Bit for

Data Block #1

B3:4

Virtual DTSW Bit for

Data Block #2

B3:3

Copy File

Source #M1:1.3628

Dest #N12:128

Length 128

0003

Virtual DTHW Bit for

Data Block #2

B3:4

This rung copies the "new" Data Block #3 data from the secondary BSN to a file within the secondary processor. When the COPy is complete, the DTHW (Data Table handshake Word) bit for Data Block #3 (B3:4/2 = M0:1.3411/2) must be set to inform the secondary BSN that the secondary processor has received the latest Data Block and is now ready for the next block of data via Data Block #3.

Virtual DTSW Bit for

Data Block #3

B3:3

Copy File

Source #M1:1.3756

Dest

Length

#N13:0

128

0004

Virtual DTHW Bit for

Data Block #3

B3:4

This rung copies the "new" Data Block #4 data from the secondary BSN to a file within the secondary processor. When the COPy is complete, the DTHW (Data Table handshake Word) bit for Data Block #4 (B3:4/3 = M0:1.3411/3) must be set to inform the secondary BSN that the secondary processor has received the latest Data Block and is now ready for the next block of data via Data Block #4.

Virtual DTSW Bit for

Data Block #4

B3:3

Copy File

Source #M1:1.3884

Dest #N13:128

Length 128

Virtual DTHW Bit for

Data Block #4

B3:4

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Programming Techniques

0005

This rung copies the "new" Data Block #5 data from the secondary BSN to a file within the secondary processor. When the COPy is complete, the DTHW (Data Table handshake Word) bit for Data Block #5 (B3:4/4 = M0:1.3411/4) must be set to inform the secondary BSN that the secondary processor has received the latest Data Block and is now ready for the next block of data via Data Block #5.

Virtual DTSW Bit for

Data Block #5

B3:3

Copy File

Source #M1:1.4012

Dest

Length

#N14:0

128

0006

Virtual DTHW Bit for

Data Block #5

B3:4

This rung copies the "new" Data Block #6 data from the secondary BSN to a file within the secondary processor. When the COPy is complete, the DTHW (Data Table handshake Word) bit for Data Block #6 (B3:4/5 = M0:1.3411/5) must be set to inform the secondary BSN that the secondary processor has received the latest Data Block and is now ready for the next block of data via Data Block #6.

Virtual DTSW Bit for

Data Block #6

B3:3

Copy File

Source #M1:1.4140

Dest

Length

#N14:128

128

0007

Virtual DTHW Bit for

Data Block #6

B3:4

This rung copies the "new" Data Block #7 data from the secondary BSN to a file within the secondary processor. When the COPy is complete, the DTHW (Data Table handshake Word) bit for Data Block #7 (B3:4/6 = M0:1.3411/6) must be set to inform the secondary BSN that the secondary processor has received the latest Data Block and is now ready for the next block of data via Data Block #7.

Virtual DTSW Bit for

Data Block #7

B3:3

Copy File

Source #M1:1.4268

Dest

Length

#N15:0

128

0008

Virtual DTHW Bit for

Data Block #7

B3:4

This rung copies the "new" Data Block #8 data from the secondary BSN to a file within the secondary processor. When the COPy is complete, the DTHW (Data Table handshake Word) bit for Data Block #8 (B3:4/7 = M0:1.3411/7) must be set to inform the secondary BSN that the secondary processor has received the latest Data Block and is now ready for the next block of data via Data Block #8.

Virtual DTSW Bit for

Data Block #8

B3:3

Copy File

Source #M1:1.4396

Dest #N15:128

Length 128

Virtual DTHW Bit for

Data Block #8

B3:4

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0009

This rung copies the "new" Data Block #9 data from the secondary BSN to a file within the secondary processor. When the COPy is complete, the DTHW (Data Table handshake Word) bit for Data Block #9 (B3:4/8 = M0:1.3411/8) must be set to inform the secondary BSN that the secondary processor has received the latest Data Block and is now ready for the next block of data via Data Block #9.

Virtual DTSW Bit for

Data Block #9

B3:3

Copy File

Source #M1:1.4524

Dest

Length

#N16:0

128

0010

Virtual DTHW Bit for

Data Block #9

B3:4

This rung copies the "new" Data Block #10 data from the secondary BSN to a file within the secondary processor. When the COPy is complete, the DTHW (Data Table handshake Word) bit for Data Block #10 (B3:4/9 = M0:1.3411/9) must be set to inform the secondary BSN that the secondary processor has received the latest Data Block and is now ready for the next block of data via Data Block #10.

Virtual DTSW Bit for

Data Block #10

B3:3

Copy File

Source #M1:1.4652

Dest

Length

#N16:128

128

0011

Virtual DTHW Bit for

Data Block #10

B3:4

This rung copies the "new" Data Block #11 data from the secondary BSN to a file within the secondary processor. When the COPy is complete, the DTHW (Data Table handshake Word) bit for Data Block #11 (B3:4/10 = M0:1.3411/10) must be set to inform the secondary BSN that the secondary processor has received the latest Data Block and is now ready for the next block of data via Data Block #11.

Virtual DTSW Bit for

Data Block #11

B3:3

Copy File

Source #M1:1.4780

Dest

Length

#N17:0

128

0012

Virtual DTHW Bit for

Data Block #11

B3:4

This rung copies the "new" Data Block #12 data from the secondary BSN to a file within the secondary processor. When the COPy is complete, the DTHW (Data Table handshake Word) bit for Data Block #12 (B3:4/11 = M0:1.3411/11) must be set to inform the secondary BSN that the secondary processor has received the latest Data Block and is now ready for the next block of data via Data Block #12.

Virtual DTSW Bit for

Data Block #12

B3:3

Copy File

Source #M1:1.4908

Dest #N17:128

Length 128

Virtual DTHW Bit for

Data Block #12

B3:4

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Programming Techniques

0013

This rung copies the "new" Data Block #13 data from the secondary BSN to a file within the secondary processor. When the COPy is complete, the DTHW (Data Table handshake Word) bit for Data Block #13 (B3:4/12 = M0:1.3411/12) must be set to inform the secondary BSN that the secondary processor has received the latest Data Block and is now ready for the next block of data via Data Block #13.

Virtual DTSW Bit for

Data Block #13

B3:3

Copy File

Source #M1:1.5036

Dest

Length

#N18:0

128

0014

Virtual DTHW Bit for

Data Block #13

B3:4

This rung copies the "new" Data Block #14 data from the secondary BSN to a file within the secondary processor. When the COPy is complete, the DTHW (Data Table handshake Word) bit for Data Block #14 (B3:4/13 = M0:1.3411/13) must be set to inform the secondary BSN that the secondary processor has received the latest Data Block and is now ready for the next block of data via Data Block #14.

Virtual DTSW Bit for

Data Block #14

B3:3

Copy File

Source #M1:1.5164

Dest

Length

#N18:128

128

0015

Virtual DTHW Bit for

Data Block #14

B3:4

This rung copies the "new" Data Block #15 data from the secondary BSN to a file within the secondary processor. When the COPy is complete, the DTHW (Data Table handshake Word) bit for Data Block #15 (B3:4/14 = M0:1.3411/14) must be set to inform the secondary BSN that the secondary processor has received the latest Data Block and is now ready for the next block of data via Data Block #15.

Virtual DTSW Bit for

Data Block #15

B3:3

Copy File

Source #M1:1.5292

Dest

Length

#N19:0

128

0016

Virtual DTHW Bit for

Data Block #15

B3:4

This rung copies the "new" Data Block #16 data from the secondary BSN to a file within the secondary processor. When the COPy is complete, the DTHW (Data Table handshake Word) bit for Data Block #16 (B3:4/15 = M0:1.3411/15) must be set to inform the secondary BSN that the secondary processor has received the latest Data Block and is now ready for the next block of data via Data Block #16.

Virtual DTSW Bit for

Data Block #16

B3:3

Copy File

Source #M1:1.5420

Dest

Length

#N19:128

128

Virtual DTHW Bit for

Data Block #16

B3:4

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Programming Techniques

9-171

0017

Virtual & Actual

DTHW Words

Move

Source B3:4

0000000000000000<

Dest M0:1.3411

0018 END

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Programming Techniques

Program File 4

0000

The following rungs are meant to be executed only when this processor/BSN is in the Primary Mode. When it is acting as the Primary Processor, this rung copies the DTCW and DTSW words to internal storage words within the SLC processor, B3:5 and B3:6 respectively, for this example.

Virtual & Actual

DTCW Words

Move

Source

Dest

M0:1.3410

B3:5

0000000000000000<

Virtual & Actual

DTSW Words

Move

Source

Dest

M1:1.3410

B3:6

0000000000000000<

0001

This rung monitors the DTCW and DTSW bits for Data Block #1. When a transfer of data using Data Block #1 is not in progress, copy up to 128 words to the appropriate

M-file location for Data Block #1 in the BSN module.

Virtual DTCW Bit for

Data Block #1

B3:5

Virtual DTSW Bit for

Data Block #1

B3:6

0 0

Copy File

Source

Dest

#N13:0

#M0:1.3500

Length 128

0002

0003

Virtual DTCW Bit for

Data Block #1

B3:7

Unlatch the virtual DTCW bit for Data Block #1 when the comparable virtual DTSW bit is set by the BSN module to indicate that it has received the last data via data Block

#1. when B3:7/0 has been unlatched, the BSN module is ready for the next data transfer via Data Block #1.

Virtual DTSW Bit for

Data Block #1

B3:6

Virtual DTCW Bit for

Data Block #1

B3:7

0 0

This rung monitors the DTCW and DTSW bits for Data Block #2. When a transfer of data using Data Block #2 is not in progress, copy up to 128 words to the appropriate

M-file location for Data Block #2 in the BSN module.

Virtual DTCW Bit for

Data Block #2

B3:5

Virtual DTSW Bit for

Data Block #2

B3:6

1 1

Copy File

Source

Dest

#N13:128

#M0:1.3628

Length 128

0004

Virtual DTCW Bit for

Data Block #2

B3:7

Unlatch the virtual DTCW bit for Data Block #2 when the comparable virtual DTSW bit is set by the BSN module to indicate that it has received the last data via data Block

#2. when B3:7/1 has been unlatched, the BSN module is ready for the next data transfer via Data Block #2.

Virtual DTSW Bit for

Data Block #2

B3:6

Virtual DTCW Bit for

Data Block #2

B3:7

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0005

This rung monitors the DTCW and DTSW bits for Data Block #3. When a transfer of data using Data Block #3 is not in progress, co py up to 128 words to the appropriate

M-file location for Data Block #3 in the BSN module.

B3:5 B3:6

2 2

Copy File

Source

Dest

#N14:0

#M0:1.3756

Length 128

0006

0007

B3:7

Unlatch the virtual DTCW bit for Data Block #3 when the comparable virtual DTSW bit is set by the BSN module to indicate that it has received the last data via data Block

#3. when B3:7/2 has been unlatched, the BSN module is ready for the next data transfer via Data Block #3.

B3:6 B3:7

2 2

This rung monitors the DTCW and DTSW bits for Data Block #4. When a transfer of data using Data Block #4 is not in progress, copy up to 128 words to the appropriate

M-file location for Data Block #4 in the BSN module.

B3:5 B3:6

Copy File

3 3 Source

Dest

Length

#N14:128

#M0:1.3884

128

0008

0009

B3:7

Unlatch the virtual DTCW bit for Data Block #4 when the comparable virtual DTSW bit is set by the BSN module to indicate that it has received the last data via data Block

#4. when B3:7/3 has been unlatched, the BSN module is ready for the next data transfer via Data Block #4.

B3:6

B3:7

This rung monitors the DTCW and DTSW bits for Data Block #5. When a transfer of data using Data Block #5 is not in progress, copy up to 128 words to the appropriate

M-file location for Data Block #5 in the BSN module.

B3:5 B3:6

4 4

Copy File

Source

Dest

#N15:0

#M0:1.4012

Length 128

0010

0011

B3:7

Unlatch the virtual DTCW bit for Data Block #5 when the comparable virtual DTSW bit is set by the BSN module to indicate that it has received the last data via data Block

#5. when B3:7/4 has been unlatched, the BSN module is ready for the next data transfer via Data Block #5.

B3:6 B3:7

4 4

This rung monitors the DTCW and DTSW bits for Data Block #6. When a transfer of data using Data Block #6 is not in progress, copy up to 128 words to the appropriate

M-file location for Data Block #6 in the BSN module.

B3:5 B3:6

5 5

Copy File

Source

Dest

#N15:128

#M0:1.4140

Length 128

0012

B3:7

Unlatch the virtual DTCW bit for Data Block #6 when the comparable virtual DTSW bit is set by the BSN module to indicate that it has received the last data via data Block

#6. when B3:7/5 has been unlatched, the BSN module is ready for the next data transfer via Data Block #6.

B3:6 B3:7

5 5

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Programming Techniques

0013

This rung monitors the DTCW and DTSW bits for Data Block #7. When a transfer of data using Data Block #7 is not in progress, copy up to 128 words to the appropriate

M-file location for Data Block #7 in the BSN module.

B3:5 B3:6

6 6

Copy File

Source

Dest

#N16:0

#M0:1.4268

Length 128

0014

0015

B3:7

Unlatch the virtual DTCW bit for Data Block #7 when the comparable virtual DTSW bit is set by the BSN module to indicate that it has received the last data via data Block

#7. when B3:7/6 has been unlatched, the BSN module is ready for the next data transfer via Data Block #7.

B3:6 B3:7

6 6

This rung monitors the DTCW and DTSW bits for Data Block #8. When a transfer of data using Data Block #8 is not in progress, copy up to 128 words to the appropriate

M-file location for Data Block #8 in the BSN module.

B3:5 B3:6

7 7

Copy File

Source

Dest

#N16:128

#M0:1.4396

Length 128

0016

0017

B3:7

Unlatch the virtual DTCW bit for Data Block #8 when the comparable virtual DTSW bit is set by the BSN module to indicate that it has received the last data via data Block

#8. when B3:7/7 has been unlatched, the BSN module is ready for the next data transfer via Data Block #8.

B3:6 B3:11

7 7

This rung monitors the DTCW and DTSW bits for Data Block #9. When a transfer of data using Data Block #9 is not in progress, copy up to 128 words to the appropriate

M-file location for Data Block #9 in the BSN module.

B3:5 B3:6

8 8

Copy File

Source

Dest

#N17:0

#M0:1.4524

Length 128

0018

0019

B3:7

Unlatch the virtual DTCW bit for Data Block #9 when the comparable virtual DTSW bit is set by the BSN module to indicate that it has received the last data via data Block

#9. when B3:7/8 has been unlatched, the BSN module is ready for the next data transfer via Data Block #9.

B3:6 B3:7

8 8

This rung monitors the DTCW and DTSW bits for Data Block #10. When a transfer of data using Data Block #10 is not in progress, copy up to 128 words to the appropriate

M-file location for Data Block #10 in the BSN module.

B3:5 B3:6

9 9

Copy File

Source

Dest

#N17:128

#M0:1.4652

Length 128

0020

B3:7

Unlatch the virtual DTCW bit for Data Block #10 when the comparable virtual DTSW bit is set by the BSN module to indicate that it has received the last data via data Block

#10. when B3:7/9 has been unlatched, the BSN module is ready for the next data transfer via Data Block #10.

B3:6 B3:7

9 9

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0021

This rung monitors the DTCW and DTSW bits for Data Block #11. When a transfer of data using Data Block #11 is not in progress, copy up to 128 words to the appropriate

M-file location for Data Block #11 in the BSN module.

B3:5 B3:6

10 10

Copy File

Source

Dest

#N18:0

#M0:1.4780

Length 128

0022

0023

B3:7

Unlatch the virtual DTCW bit for Data Block #11 when the comparable virtual DTSW bit is set by the BSN module to indicate that it has received the last data via data Block

#11. when B3:7/10 has been unlatched, the BSN module is ready for the next data transfer via Data Block #11.

B3:6 B3:7

10 10

This rung monitors the DTCW and DTSW bits for Data Block #12. When a transfer of data using Data Block #12 is not in progress, copy up to 128 words to the appropriate

M-file location for Data Block #12 in the BSN module.

B3:5 B3:6

11 11

Copy File

Source

Dest

#N18:128

#M0:1.4908

Length 128

0024

0025

B3:7

Unlatch the virtual DTCW bit for Data Block #12 when the comparable virtual DTSW bit is set by the BSN module to indicate that it has received the last data via data Block

#12. when B3:7/11 has been unlatched, the BSN module is ready for the next data transfer via Data Block #12.

B3:6 B3:7

11 11

This rung monitors the DTCW and DTSW bits for Data Block #13. When a transfer of data using Data Block #13 is not in progress, copy up to 128 words to the appropriate

M-file location for Data Block #13 in the BSN module.

B3:5 B3:6

12 12

Copy File

Source

Dest

#N19:0

#M0:1.5036

Length 128

0026

0027

B3:7

Unlatch the virtual DTCW bit for Data Block #13 when the comparable virtual DTSW bit is set by the BSN module to indicate that it has received the last data via data Block

#13. when B3:7/12 has been unlatched, the BSN module is ready for the next data transfer via Data Block #13.

B3:6

B3:7

This rung monitors the DTCW and DTSW bits for Data Block #14. When a transfer of data using Data Block #14 is not in progress, copy up to 128 words to the appropriate

M-file location for Data Block #14 in the BSN module.

B3:5 B3:6

Copy File

13 13 Source

Dest

Length

#N19:128

#M0:1.5164

128

0028

B3:7

Unlatch the virtual DTCW bit for Data Block #14 when the comparable virtual DTSW bit is set by the BSN module to indicate that it has received the last data via data Block

#14. when B3:7/13 has been unlatched, the BSN module is ready for the next data transfer via Data Block #14.

B3:6 B3:7

13 13

Publication 1747-6.22

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Programming Techniques

0029

This rung monitors the DTCW and DTSW bits for Data Block #15. When a transfer of data using Data Block #15 is not in progress, copy up to 128 words to the appropriate

M-file location for Data Block #15 in the BSN module.

B3:5 B3:6

14 14

Copy File

Source #N20:0

Dest

Length

#M0:1.5292

128

0030

0031

B3:7

Unlatch the virtual DTCW bit for Data Block #15 when the comparable virtual DTSW bit is set by the BSN module to indicate that it has received the last data via data Block

#15. when B3:714 has been unlatched, the BSN module is ready for the next data transfer via Data Block #15.

B3:6 B3:7

14 14

This rung monitors the DTCW and DTSW bits for Data Block #16. When a transfer of data using Data Block #16 is not in progress, copy up to 128 words to the appropriate

M-file location for Data Block #16 in the BSN module.

B3:5 B3:6

15 15

Copy File

Source

Dest

#N20:128

#M0:1.5420

Length 128

0032

0033

B3:7

Unlatch the virtual DTCW bit for Data Block #16 when the comparable virtual DTSW bit is set by the BSN module to indicate that it has received the last data via data Block

#16. when B3:7/15 has been unlatched, the BSN module is ready for the next data transfer via Data Block #16.

B3:6 B3:7

15 15

Virtual & Actual

DTCW Word

Move

Source B3:7

0000000000000000<

Dest M0:1.3410

0034 END

Publication 1747-6.22

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Data Transfer Schemes

This manual provides two possible methods for transferring data from a primary to a secondary processor

The first programming alternative transfers a data block per program scan. With this method, the application program defines the order that is used for transferring the data blocks. This programming scheme results in a lower overall data transfer throughput and has a minimal impact in the program scan time.

The second programming alternative transfers each data block at its maximum possible throughput. This method is shown in the ladder program example earlier in this chapter. With this method, the application program tries to make all the possible data transfers in each program scan, according to the DTSW bits.

Data Transfer Method 1

With this alternative, the primary SLC 5/0x uses a counter to select the 1747-BSN module to which the data block is sent. The primary

SLC 5/0x also uses a second counter to select which block is sent to the BSN module. If the system has only one 1747-BSN, only one counter is used. The following procedure is used in the primary SLC

5/0x for sending the data blocks:

1. Read all the DTSWs from the respective 1747-BSN modules.

2. Clear all DTCW bits corresponding to the data blocks that are marked as already transferred to secondary system in the

DTSWs. Send the data blocks to their respective 1747-BSN modules.

3. Look at the counters and DTSWs to check whether the next data block that is sent is able to receive new data from the SLC 5/0x:

• If the next data block is not able to receive new data, increment the data block counter and check whether it is time to select the next 1747-BSN module.

• If the next data block is able to receive new data, increment the module counter, restart the data block counter and repeat step 3.

(Repeat this step until all possible data blocks are scanned.)

4. Copy the data block from the SLC 5/0x to the 1747-BSN module indicated by the module counter.

5. Advise the 1747-BSN module that the data block is ready through the DTCW (set the bit corresponding to the data block in this word).

6. Increment the data block counter and check whether it is time to select the next 1747-BSN module. If it is time to select the next module, increment the module counter and restart the data block counter.

7. Start step 1 in the next program scan.

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Programming Techniques

To receive the data blocks, the secondary SLC 5/0x application program uses the following procedure:

1. Read all the DTSWs from the respective 1747-BSN modules.

2. Clear all DTHW bits corresponding to the data blocks that were previously read and that no longer have a data ready bit set for them in the DTSWs. Send all the DTHWs to their respective

1747-BSN modules.

3. Look at the counters and DTSWs to check whether the next data block that is received is ready in the 1747-BSN module

• If the next data block is not ready, increment the data block counter and check whether it is time to select the next 1747-

BSN module.

• If the next data block is ready, increment the module counter, restart the data block counter and repeat step 3. (Repeat this step until all possible data blocks are scanned.)

4. Copy the data block from the 1747-BSN module to the

SLC 5/0x.

5. Advise the 1747-BSN module that the data block was already read through the DTHW (set the bit corresponding to the data block in this word).

7. Start step 1 in the next program scan.

The worst scenario with this transfer method is a system that has eight

1747-BSN modules in which each one is transferring 16 data blocks.

The total number of data blocks is 128 and the backup system spends

128 program scans to transfer all the data blocks.

Data Transfer Method 2

With method 2, the application program in the SLC 5/0x considers each data block independent from the other data blocks. This is shown in the ladder program example earlier in this chapter for one set of BSN modules. Reproduce this logic for additional sets of BSN modules, being sure to update the slot number in the M-file addresses for each set. The following procedure is used in the primary SLC 5/0x for sending the data blocks:

1. Read all the DTSWs from the respective 1747-BSN modules.

2. Clear all DTCW bits corresponding to the data blocks that are marked as already transferred to secondary system in the

DTSWs. Send the data blocks to their respective 1747-BSN modules.

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3. For each data block, do the following:

• Check whether the block is free to receive new data from the

SLC 5/0x.

• Copy the data block from the SLC 5/0x to the 1747-BSN module.

• Advise the 1747-BSN module that the data block is ready through the DTCW (set the bit corresponding to the data block in this word).

4. Start step 1 in the next program scan.

To receive the data blocks, the secondary SLC 5/0x application program uses the procedure below:

1. Read all the DTSWs from the respective 1747-BSN modules.

2. Clear all DTHW bits corresponding to the data blocks that were previously read and that no longer have a data ready bit set for them in the DTSWs. Send all the DTHWs to their respective

1747-BSN modules. For each data block, do the following:

• Check whether the data block is ready in the 1747-BSN module.

• Copy the data block from the 1747-BSN to the SLC 5/0x.

• Advise the 1747-BSN module that the data block was already read through the DTHW (set the bit corresponding to the data block in this word).

3. Start step 1 in the next program scan.

The worst scenario with this transfer method is a system with eight

1747-BSN modules in which each one is transferring 16 data blocks.

The total number of data blocks is 128. In each program scan, the system transfers all 128 data blocks. Total transfer time is approximately 700 msec.

Other transfer methods

Data transfer methods 1 and 2 were designed to be used as sample methods. In a real application, the user would develop other methods of transferring data. Theses alternatives would optimize the data transfer throughput without causing an excessive loss of time due to the M-file transfers.

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Programming Techniques

Accounting for

Instructions That

Could Cause Problems

During Switchover

Some instructions may operate unpredictably when a switchover occurs if you fail to observe certain programming considerations. For example, you must consider transferring the control element and data elements for instructions that are also being executed in the secondary processor. You also must consider transferring data files which contain more than one word.

The following instructions are discussed in this section:

• timer

• counter

• logical, arithmetic, compare and move

• diagnostic, sequencing, file arithmetic and logic, file search and compare, file

• copy and fill

• FIFO and bit displacement

• block transfer

• message

In the remainder of this chapter, we describe the behavior of these instructions in the SLC 500 backup system.

Important:

The primary and secondary systems do not necessarily execute the same instructions at the same time (the systems’ program scans are not synchronized). Note also that the SLC 500 processor executes block transfers to the program scan asynchronously. Therefore, the processor interrupts the program scan asynchronously to access block transfer write (BTW) and block transfer read (BTR) files.

Timer Instructions

The SLC 500 processors maintain timers by keeping a copy of a hardware timer in a portion of the three-word structure (timer byte) used by each timer.

Control byte Timer byte

Preset value

Accumulated value

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The hardware timer of the primary processor is completely asynchronous to the hardware timer of the secondary processor. If the whole three-word timer structure, including the timer-byte, is transferred from the primary to the secondary processor during a switchover, then the timer could encounter a large positive increment in the timer accumulated value. The worst-case increment may be as much as 2.55 seconds.

Follow the guidelines below to help avoid this type of increment in the timer accumulated value:

• do not send the first word of the timer control structure

• transfer only the accumulated value. (Transfer the preset value also, if you need to change it.)

Even though both processors are executing the same programs, your program should transfer the timer accumulated value from the primary processor to the secondary processor at least once after you:

• start the backup system

• switch the secondary SLC 500 from PROGRAM to RUN mode

• restart a repaired system

This allows the accumulated value in the secondary processor to track the accumulated value in the primary processor.

Counter Instructions

Counter instructions are similar in structure to timer instructions.

However, when a switchover occurs, a counter that occurs once in a program could increment or decrement twice in one program scan.

This problem arises when the following sequence of events occur:

1. The primary system executes a counter up/down instruction conditioned by a rung transition of not-true to true. This increments/decrements the counter accumulated value.

2. The 1747-BSN modules transfer this data into the counter file of the backup processor before the secondary’s input image table is updated with the input transition information.

3. The backup processor updates its input image table.

4. The processor in the secondary system (which was at a different point in its program scan) executes the counter instruction again, thus incrementing/decrementing the counter again.

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Programming Techniques

As with the timer instruction, your program should transfer the counter accumulated value from the primary to the secondary processor at least once after you:

• start the backup system

• switch the secondary SLC 500 from PROGRAM to RUN mode

• restart a repaired system

This allows the accumulated value in the secondary processor to track the accumulated value in the primary processor.

Diagnostic, Sequencing, File Arithmetic and Logic, File Search and Compare, File Copy and Fill Instructions

The type of data you are transferring, as well as how you transfer the data to the secondary processor, determines the behavior of the following file instructions:

• File Arithmetic and Logic instructions (FAL)

• File Search and Compare (FSC)

• File Copy (COP)

• File Fill (FLL)

• Diagnostic (FBC and DDT)

You should place the instruction’s control element data file within the same 62 words of data. If this is not done, the 1747-BSN module could transfer the control values responsible for control of the file at a different point than when it transfers the file. A time lag between when the file is updated and when the associated control element is updated in the secondary processor. As a result, the following may occur during switchover:

• file operation that was running may be off by one word

• a word could be operated on by the file twice

• a word could not even be operated at all.

FIFO and Bit Displacement Instructions

The type of data you are transferring, as well as how you transfer the data to the secondary processor, determines the behavior of the FIFO and Bit Displacement instructions.

If you are transferring only selected areas of the data files which do not include data for FIFO and bit instructions, the instructions are executed normally.

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However, if you are transferring all of the data table files over the

HSSL, you may encounter problems. For example, if you are shifting four bits of BCD data through several words bit by bit, the data table contains invalid data until each shift is complete. Should the 1747-

BSN module transfer one or more of these values to the backup system and the primary system fails, the data table of the backup system contains intermediate values for an indefinite amount of time.

The result is illegal BCD values.

Block Transfer Instructions

It is impossible to guarantee that both processors are executing a given BTW or BTR at the same time. This is because the remote I/O scans are not synchronized and the block transfer data is not transferred instantaneously by both SLC 500 processors. The BTR files in the secondary processor always reflect information contained in the primary processor, except with a time delay.

To avoid the possibility of block transfer data changing during the scan of the program, you can buffer data at the beginning of the ladder program to ensure continuity.

Another potential problem with block transfer instructions is that during switchover, the secondary scanner may skip one or more remote adapters. This may happen because the “new” primary scanner (previously the secondary) was in a different place in its remote I/O chassis scan.

Message Instructions

In your backup system, the secondary processor is disconnected from the Data Highway Plus link. Therefore, it cannot execute message instructions. When programming, you must ensure that when a switchover occurs, that any messages which were running in the primary processor are subsequently enabled in the secondary processor. You can do this by conditioning message instruction rungs in both the primary and secondary processors using the primary/ secondary bit of the 1747-BSN status word. If necessary, you can pass the results of a message addressed to the primary processor over the

HSSL to the secondary processor.

PRI/SEC

Message

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Programming Techniques

Summary of

Programming

Considerations

PID Control Files

When using PID instructions, you can send all or part of these control files, based on how you back up your PID instructions and the total amount of data to be sent by the BSN modules. Keep in mind that the control files contain such things as your setpoint, gains, and words that are used by the PID instruction for internal storage and should not be manipulated unnecessarily.

When developing a program for the SLC 500 backup system, you must always consider the following:

• non-synchronous I/O scans

• execution times of block transfer instructions

• time for transfer of data from the primary to the secondary processor

• the need to reduce the quantity of data to be transferred, and gathering all related data into a single block

• synchronization of discrete I/O data with regard to program scans even though remote I/O scans are performed asynchronously

• the need to disable message instructions in the secondary processor using the primary/secondary bit

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Appendix

Specifications

Backup Scanner

Operating

Specifications

This appendix provides and system specifications, as well as throughput information, for the Backup Scanner Module. Topics include:

• scanner operating specifications

• network specifications

• throughput introduction

• calculating throughput

Backplane Current Consumption

Operating Temperature

Storage Temperature

Humidity

Noise Immunity

Agency Certification

(when product or packaging is marked)

800 mA at 5V

+32°F to +140°F (0°C to +60°C)

-40°F to +185°F (-40C to +85°C)

5 to 95% without condensation

NEMA Standard ICS 2-230

UL listed

C-UL listed - Class I, Division 2, Groups A, B, C,

D Temp. Code T3C

CE compliant for all applicable directives

Network Specifications

Baud Rate Determination of Maximum Cable Length and Terminating Resistor Size

Using

Extended Node

Capability

Not Using

Extended Node

Capability

Baud Rate

57.6K baud

115.2K baud

230.4K baud

57.6K baud

115.2K baud

230.4K baud

Max. Cable Distance

(Belden™ 9463)

3048 m (10,000 ft.)

1524 m (5,000 ft.)

762 m (2,500 ft.)

3048 m (10,000 ft.)

1524 m (5,000 ft.)

762 m (2,500 ft.)

Resistor Size

Ω

1/2 Watt

Gray-Red-Black-Gold

150

Ω

1/2 Watt

Brown-Green-Brown-

Gold

Ω

1/2 Watt

Gray-Red-Black-Gold

DIP Switch Position for Baud Rate Selection

Position 1

OFF

Position 2

OFF

Baud Rate

57.6K

115.2K

230.4K

Disabled

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Specifications

Throughput

Introduction

RIO throughput is defined as the time between when an input event occurs at an I/O module in an RIO chassis to when an output event occurs at an I/O module within the same RIO chassis. There are three types of throughput concerning the 1747-BSN Backup Scanner

Module and its RIO network:

• discrete throughput (time from discretely mapped input to discretely mapped output) without block transfers (BTs) present

• discrete throughput (time from discretely mapped input to discretely mapped output) with BTs present

• BT throughput (time from when a BT is enabled to when the BT successfully completes)

RIO Network Throughput Components

The following components affect RIO network throughput:

• the total SLC processor scan time

• the total RIO link scan time

• adapter(s) backplane scan time(s)

• the backup scanner’s output delay time

• the backup scanner’s input delay time

• input module delay times

• output module delay times

Processor Scan

Scanner Scan

Scanner

Processor

ASB Module

I/O Module

ASB Backplane Scan

I/O Module

RIO Scan

SLC Local

Chassis

Outputs to Modules

Inputs to Modules

When the SLC control program detects that the remote input has been turned on (via the scanner input image), it activates the remote output device (via the scanner output image). Throughput is then defined as the time between when the remote input device is activated to when the remote output turns on.

Remote Chassis

Inputs to Modules

Remote Expansion

Chassis

Outputs from Modules

Output Device

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Calculating

Throughput

Specifications

A-187

The 1747-BSN Backup Scanner’s throughput is determined by using the formulas provided in this section.

Discrete I/O Throughput without Block Transfers (T

dm-nbt)

Present

The information in this section is used to calculate the discrete throughput of the 1747-BSN Backup Scanner if there are no BTs occurring on the RIO link to any chassis.

If BTs are present on the RIO link you must use the Discrete I/O

Throughput with Block Transfers (T dm-bt

) Present section to determine your throughput.

The formula to calculate the maximum backup scanner discrete I/O throughput without BTs present is:

T dm-nbt

= 2T ps +

RIO +

T adp +

SNo +

SNi +

T id +

T od

T dm-nbt

= The maximum discrete throughput without BTs in milliseconds (ms)

To calculate T dm-nbt

throughput, substitute values for the variables in the formula above. Locate these values in the following documents

T ps

RIO

Variable

T adp

SNo

SNi

T id

T od

Variable Description

The total processor scan time

(ms)

Location of Variable

The total RIO scan time (ms)

The adapter throughput delay.

For a 1747-ASB, this is two ASB backplane scan times.

The backup scanner module output delay time (ms)

The backup scanner module input delay time (ms)

The input module delay time

(ms)

The output module delay time

(ms)

APS reference manual see the section RIO Scan Time

Calculation (T

RIO) on page B-4 adapter user manual see the section Backup Scanner

Output Delay Time (T

SNo

) on page B-11

5 ms (constant value for all formulas in this appendix)

I/O product data and I/O instruction sheets

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Specifications

RIO Scan Time Calculation (T

RIO

)

The RIO scan time is calculated by identifying the baud rate and image size of each logical device on the RIO link. Locate the corresponding time value in the following table. If you are using multiple logical devices, add the time values together to determine the total RIO scan time (T

RIO

RIO

= T adapter 1 +

T adapter 2 +

T adapter 3

Adapter

Size

1/4 logical rack

1/2 logical rack

3/4 logical rack

Full logical rack

RIO Scan Times for Adapters

Baud Rate

57.6K

115.2K

230.4K

6.0 ms

6.5 ms

7.5 ms

9.5 ms

3.5 ms

4.0 ms

4.5 ms

5.5 ms

2.5 ms

2.75 ms

3.0 ms

3.5 ms

Example Discrete I/O Throughput without Block Transfers

Present

An SLC 5/03 is controlling an RIO link running at 115.2K baud that has the following adapters:

• One 1747-ASB module is configured as a 1/2 logical rack starting at logical rack 0.

I/O chassis slot 1 contains 1746-IB16, 16 point input module

I/O chassis slot 2 contains 1746-OB16, 16 point output module

• Two adapters are each configured as full logical racks (logical racks 1 and 2).

• Three adapters are each configured as 1/4 logical racks (logical rack 3).

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You need to calculate your T dm-nbt

: the RIO throughput time from when the input closes on the 1746-IN16 until the output on the

1746-OB16 is on.

1. Use the throughput formula to calculate the maximum throughput.

T dm-nbt

= 2T ps +

RIO +

T adp +

SNo +

SNi +

T id +

T od

T ps

= 25.0 ms

RIO

= The total RIO scan time (ms)

SNo

= See value in the table on page B-13, TSNo without M0

File

Writes

(Normal Mode).

SNi

= 5.0 ms

T id

= 10.0 ms, which is from I/O module instruction sheets

T od

= 1.0 ms, which is from I/O module instruction sheets

T dm-nbt

= 2(25.0)

RIO

+ 8.0 + T

SNo

+ 5.0 + 10.0 + 1.0

2. Calculate the total RIO scan time (T

RIO).

Locate the baud rate

(115.2K) and adapter size, which is found in the table on page B-

4. Multiply the RIO scan times listed under the 115.2K heading by the number of each different type of rack that you have. Add those numbers together:

RIO

= T adapter 1 +

T adapter 2 +

T adapter 3

RIO

= 1(4.0 ms) + 2(5.5 ms) + 3(3.5 ms

)

RIO

= 25.5 ms

3. Find T

SNo

on page B-13 in the table T

SNo without M0 File

Writes (Normal Mode). For this example T upd

> T hold

, and there are 4 logical racks configured. Therefore:

SNo

= 7.0 ms

4. Substitute all the values for variables in the throughput formula and solve for throughput:

T dm-nbt

= 2T ps +

RIO +

2T bp +

SNo +

SNi +

T id +

T od

T dm-nbt

= 2(25.0)+ 2(25.5) + 8.0 + 7.0 + 5.0 + 10.0 + 1.0

T dm-nbt

= 132.0 ms = maximum throughpu t

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Specifications

Discrete I/O Throughput with Block Transfers (T

dm-bt

) Present

The information in this section is used to calculate the discrete throughput of the 1747-BSN Backup Scanner if there are BTs occurring on the RIO link to any chassis.

If BTs are not present on the RIO link, you must use the Discrete I/O

Throughput without Block Transfers (Tdm-nbt) Present section to determine your throughput. See page B-3.

The formula to calculate discrete I/O throughput with BTs present is:

T dm-bt

= 2T ps +

RIO +

2T btx +

T adp +

SNo-bt +

SNi +

T id +

T od

T dm-bt

= The maximum discrete throughput with BTs in milliseconds (ms)

To calculate T dm-bt throughput, substitute values for the variables in the formula above. Locate these values in the following documents:

Variable

T ps

RIO

T btx

T adp

SNo-bt

SNi

T id

T od

Variable Description

The total processor scan time

(ms)

The total RIO scan time (ms)

Additional time due to sending any BT data on the RIO link.

The adapter throughput delay.

For a 1747-ASB, this is two

ASB backplane scan times.

Backup scanner output delay time with BTs present

The backup scanner module input delay time (ms)

The input module delay time

(ms)

The output module delay time

(ms)

Location of Variable

APS reference manual see the section RIO Scan Time

Calculation (T

RIO) on page B-4 see the section Determining

T btx on page B-7 adapter user manual see the section Determining

SNo-bt on page B-7

5 ms (constant value for all formulas in this appendix)

I/O product data and I/O instruction sheets

Determining T

SNo-bt

Use the following table to find T

SNo-bt for your particular configuration.

Important:

The times shown are, to the best of our knowledge, the maximum delay times of the backup scanner. However, in instances that throughput is an important consideration, test the application thoroughly first to ensure proper operation. Note that in most situations the average throughput is much better than the calculated maximum throughput.

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1 Logical Rack

2 Logical Racks

3 Logical Racks

4 Logical Racks

All Baud Rates

16.0

19.0

22.0

25.0

19.0

23.0

26.0

28.0

57.6K baud

24.0

27.0

30.0

34.0

115.2K baud

32.0

36.0

39.0

42.0

230.4K baud

Determining T btx

Before determining (T btx), you need to establish the maximum BT write or read length that is to be processed by each logical rack on the

RIO link. RIO scan time is increased each time an BT is sent to any logical device on the RIO network. The scan time increase depends on the number of words sent in the BT and the selected baud rate.

RIO link protocol allows for a maximum of one BT to be sent to each logical rack on the RIO link during any single RIO scan. Therefore, if multiple BTs are sent to devices within the same logical rack, only the longest BT to that logical rack needs to be considered to determine your maximum throughput. The RIO scan time increase

(T ri) for each logical rack is:

Baud Rate

57.6K baud

115.2K baud

230.4K baud

RIO Scan Time Increase (T ri)

0.300 x BT length + 5.0 ms

0.150 x BT length + 3.5 ms

0.075 x BT length + 2.0 ms

The total increase in the RIO scan time (T btx) is equal to:

T btx

= sum of Tri for all logical racks

Example Discrete I/O Throughput with Block Transfers Present

An SLC 5/03 is using a backup scanner to control a 115.2K baud RIO link that has 3 adapters and 4 logical devices.

Adapter #1 (1747-ASB module):

• starting logical rack 0, logical group 0

• 12 logical groups (1 1/2 logical racks)

• one 8 word and two 4 word BT write/read modules in logical rack 0

• one 2 word BT write/read module in logical rack 1

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Specifications

Adapter #2 (1771-ASB module):

• starting logical rack 2, logical group 0

• 2 logical groups (1/4 logical rack)

• one 64 word BT write/read module

Adapter #3 (1771-ASB module):

• starting logical rack 2, logical group 2

• 2 logical groups (1/4 logical rack)

• one 32 word BT write/read module

1. Use the throughput formula to calculate the maximum throughput of the 1747-ASB module.

T dm-bt

= 2T ps

+ 2T

RIO

+ 2T btx

+ T adp

+ T

SNo-bt

+ T

SNi

+ T id

+ T od

T ps

= 25.0 ms, which is from the APS reference manual (assume for example)

RIO

= The total RIO scan time (ms)

T btx

= Additional time due to sending any BT data on the RIO link

T adp

= Two 1747-ASB module backplane scan times (calculated from ASB

manual) = 2(4.5) = 9.0 ms

SNo-bt

22.0 ms from the table on page B-13, TSNo with

Block Transfers

(Normal Mode). There are 3 logical racks configured.

SNi

= 5.0 ms

T id

= 10.0 ms, which is from I/O module instruction sheets

T od

= 1.0 ms, which is from I/O module instruction sheets

T dm-bt

= 2(25.0) + 2T

RIO

+ 2T btx

+ 9.0 + 22.0 + 5.0 + 10.0 + 1.0

2. Calculate the total RIO scan time (T

RIO

). Locate the baud rate

(115.2K) and adapter size which is found in the table on page B-

4. Multiply the RIO scan times listed under the 115.2K heading by the number of each different type of rack that you have. Add those number together.

RIO

= Tadapter1 + Tadapter2 + Tadapter3

RIO

= 1(5.5) + 1(4.0) + 2(3.5)

RIO

= 16.5 ms

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3. Calculate the maximum T ri time for each logical rack. Do this by determining the largest BT that occurs to any device within a logical rack and calculating the transfer time using the table on page B-7. Then add together the T ri times for each logical rack to obtain T btx

T ri for rack 0 = 0.150(8) + 3.5 = 4.7 ms (maximum BT to rack 0 is 8 words)

T ri for rack 1 = 0.150(2) + 3.5 = 3.8 ms (maximum BT to rack 1 is 2 words)

T ri for rack 2 = 0.150(64) + 3.5 = 13.1 ms (maximum BT to rack

2 is 64 words)

T btx

= Tri0 + Tri1 + Tri2 = 4.7 + 3.8 + 13.1 = 21.6 ms

4. Substitute all the values for variables in the throughput formula and solve for throughput.

T dm-bt

= 2(25.0) + 2(16.5) + 2(21.6) + 9.0 + 22.0 + 5.0 + 10.0 +

1.0

T dm-bt

= 173.2 ms = maximum throughput

Block Transfer Throughput

Block transfer throughput is the time from when the BT is enabled via the EN bit, until the DN bit is processed. The following BT timing explanations are based on the directional continuous BT example shown on page, where a BT is re-triggered automatically upon each completion.

BT throughput is always slower than discrete data transfer.

Completing a BT is dependent on the time involved for the:

• SLC control program to enable the BT via an M0 file write

• backup scanner to detect that a BT has been requested

• BT to be waiting in the queue due to another BT already being processed on the same logical rack

• backup scanner to schedule a pending bit

• adapter to acknowledge the request

• backup scanner to initiate the BT and transfer the data

• SLC control program to detect that the BT has completed (DN flag set)

1. This is dependent on the SLC processor you are using.

2. Refer to the equations that follow.

3. The RIO network allows only one BT per logical rack (not logical device) per RIO scan. Therefore, if multiple BTs are performed on devices within the same logical rack, BTs have to wait in the queue until any previously scheduled BTs for the same logical rack are completed.

4. This is dependent on the RIO adapter.

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A-194

Specifications

The time to free up the BT buffer (by clearing the EN flag so another

BT can be performed) depends on the:

• instruction time of the M0 file write which clears the EN flag

• time for the backup scanner to detect that the EN flag has been cleared

• time for SLC control program to detect that the DN flag has been cleared

The formula to calculate BT throughput is:

M0 +

SNo-bt

(number of BTs + 1) + T btwait +

RIO +

T adp-bt +

T ps btx +

The equation for freeing up the BT buffer is:

M0 +

No-bt

(number of BTs) + T ps

Substitute values for the variables in the formulas above. Locate these values in the following documents:

Variable

SNo-bt btwait

Variable Description

Time to perform M0 file write to enable BT

Backup Scanner Output Delay time with BTs present. There must be an output delay time added for each BT buffer that is being used since the backup scanner processes only one BT enable or disable every T

SNo-bt

(to minimize the impact on discrete I/O throughput).

Equals the sum of the throughput times for all BTs scheduled to the same logical rack

(time waiting is queue), + T

SNo-bt

(time to schedule pending BT). If multiple BTs are not being performed to the same logical rack, this value equals zero.

Location of Variable

appendix B see the section

Determining T

SNo-bt page B-7 calculated on

RIO

RIO scan time without BTs see the section RIO Scan

Time Calculation (T

RIO) page B-4 on

T btx adp-bt ps

Amount that the RIO scan time can be increased due to BTs. This includes the time for the backup scanner to initiate the

BT and transfer the data.

Time for the adapter to acknowledge the BT request. For the 1747-ASB, the manual defines this as no more than one (ASB) backplane scan time and two RIO scans.

However, the two RIO scans are already included in the above equation so only the

ASB scan time needs to be added.

One processor scan time may occur before the SLC control program detects that the DN flag has been set or cleared see the section

Determining T btx

B-7 on page adapter user manual

APS reference manual

1. When calculating BT throughput, one T

SNo-bt

is also required to handle the BT response

1. This is dependent on the SLC processor you are using.

2. Refer to the equations that follow.

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Specifications

A-195

Backup Scanner Output Delay Time (T

SNo

) Tables

The tables provided in this section show the maximum backup scanner output delay time (T

SNo

) for specific applications. T

SNo

is dependent on the following:

• processor scan time, or time between immediate outputs (if no

BTs are present)

• number of logical racks configured

• whether normal or complementary I/O mode is selected

• RIO baud rate (if complementary I/O is selected)

SNo

Variable

T upd

T hold

Variable Description

The maximum scanner output delay time

The time between SLC processor output scan updates or immediate output updates

A constant time threshold that is dependent on your configuration. Refer to the table on page B-12.

SNo increases if the interval between Tupd decreases to the time threshold (Thold). If Tupd is less than Thold, then the larger TSNo number must be used. Otherwise, either number may be used.

Important:

The times shown in this section are, to the best of our knowledge, the maximum delay times of the backup scanner. However, in instances that throughput is an important consideration, test the application thoroughly first to ensure proper operation. Note that in most situations the average throughput is much better than the calculated maximum throughput.

Determining the Number of Logical Racks Configured

The number of logical racks configured is determined by the number of racks that contain configured devices. For example, if there are four 1/4 rack devices in logical rack 0 and one full rack device in logical rack 3, there would be two logical racks configured. Note that the number of logical devices on the RIO network affects only T

RIO, and only affects TSNo when additional logical racks are used.

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Specifications

When complementary mode is selected, the number of configured racks is also determined by the number of primary or complementary racks configured, but not by both. (The maximum number of configured racks is 4.) That is, if there is a primary rack configured with a corresponding complementary rack, that is considered one logical rack. If there is a primary rack configured without a complementary rack (or vice versa), that also is considered one logical rack.

SNo

without M0 File Writes

Number of Logical

Racks Configured

1 Logical Rack

2 Logical Racks

3 Logical Racks

4 Logical Racks

Normal Mode

All Baud Rates

SNo

if Tupd

Thold

5.0

7.0

9.0

11.0

Thold

5.0

7.0

9.0

11.0

SNo

if Tupd

Thold

2.5

4.0

5.5

7.0

Publication 1747-6.22

Appendix

M0-M1 Files and G Files

This appendix contains important information about M0-M1 files and

G files. The information is general in nature and supplements specific information contained in earlier chapters of this manual.

Topics include:

• M0-M1 Files

• G Files

M0 and M1 files are data files that reside in specialty I/O modules only. There is no image for these files in the processor memory. The application of these files depends on the function of the particular specialty I/O module. With respect to the SLC processor (SLC 5/02 or later), the M0 file is a module output file (a write only file) and the

M1 file is a module input file (a read only file). The opposite is true for specialty I/O modules, where the M0 file is a read only file, and the M1 file is a write only file.

M0-M1 Files

M0 and M1 files can be addressed in your ladder program and they can also be acted upon by the specialty I/O module - independent of the processor scan. It is important that you keep the following in mind in creating and applying your ladder logic:

Important:

During the processor scan, the ladder program can address M0 and M1 data with bit, word, or file instructions. Each time an M0-M1 file address is encountered in the program, an immediate data transfer to or from the specialty I/O module occurs. The impact these immediate data transfers have on processor scan time is described in appendix D of the SLC 500 and

MicroLogix 1000 Instruction Set Reference Manual,

Publication 1747-6.15.

Configuring M0-M1 Files

READ

CONFIG

ONLINE

CONFIG

M0 and M1 files are configured as part of the I/O configuration procedure for the processor file. After you have assigned the specialty

I/O module to a slot (the procedure is the same as assigning other modules), the following functions appear at the bottom of the screen:

MODIFY

RACKS

MODIFY

SLOT

DELETE

SLOT

UNDEL

SLOT

EXIT

SPIO

CONFIG

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B-198

M0-M1 Files and G Files

Complete the following steps to configure the M0 and M1 files:

1. Press

[F9]

, Specialty I/O Configuration. The following functions appear:

ISR

NUMBER

MODIFY

G FILE

ADVNCD

SETUP

G FILE

SIZE

2. Press

[F5]

, Advanced Setup. The following functions appear:

INPUT

SIZE

OUTPUT

SIZE

SCANNED

INPUT

SCANNED

OUTPUT

M0 FILE

SIZE

M1 FILE

SIZE

3. Press

[F5]

, then enter the number of M0 file words required (the required number is listed in the user manual for the specific specialty I/O module).

4. Press

[F6]

, then enter the number of M1 file words required (the required number is listed in the user manual for the specific specialty I/O module).

The specialty I/O module may require that you also configure the G file and specify an ISR (interrupt subroutine) number. These tasks are accomplished with function keys F1, F3, and F7 shown in step 1 above. G files are discussed later in this appendix.

Addressing M0-M1 Files

The addressing format for M0 and M1 files is below:

Mf:e.s/b

Where

M = module f = file type (0 or 1) e = slot (1-30) s = word (0 to max. supplied by module b = bit (0-15)

Using M0-M1 Data File Addresses

M0 and M1 data file addresses can be used in all instructions except the OSR instruction and the instruction parameters noted below:

Instruction

BSL, BSR

SQO, SQC, SQL

LFL, LFU

FFL, FFU

Parameter (uses file indicator #)

File (bit array)

File (sequencer file)

LIFO (stack)

FIFO (stack)

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M0-M1 Files and G Files

B-199

Monitoring Bit Addresses

For SLC 5/02 processors, the M0/M1 Monitoring option is always disabled. (This processor does not allow you to monitor the actual state of each addressed M0/M1 address.) For SLC 5/03 and SLC 5/04 processors, you can choose to disable or enable the monitoring option by selecting

[F6]

, System Config, from the main menu.

M0/M1 Monitoring Option Disabled

When you monitor a ladder program in the Run or Test mode with the

M0/M1 Monitoring option disabled, the following bit instructions, addressed to an M0 or M1 file, are indicated as false regardless of their actual true/false logical state.

Mf:e.s

] [

Mf:e.s

]/[

Mf:e.s

( )

Mf:e.s

(L)

Mf:e.s

(U)

f = file (0 or 1)

When you are monitoring the ladder program in the Run or Test mod, the HHT display does not show these instructions as being true when the processor evaluates them as true.

If you need to show the state of the M0 or M1 addressed bit, you can transfer the state to an internal processor bit. This is illustrated below, where an internal processor bit is used to indicate the true/false state of a rung.

] [

EQU

EQUAL

Source A N7:12

M0:3.0

( )

Source B N7:3

This rung will not show its true rung state because the EQU instruction is always shown as true and the M0 instruction is always shown as false.

] [

EQU

EQUAL

Source A

Source B

N7:12

N7:3

( )

M0:3.0

( )

OTE instruction B3/2 has been added to the rung. This instruction shows the true or false state of the rung.

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B-200

M0-M1 Files and G Files

M0/M1 Monitoring Option Enabled

Important:

This option is not supported by the SLC 5/02 processor.

The SLC 5/03 and SLC 5/04 processors allows you to monitor the actual state of each addressed M0/M1 address (or data table). The highlighting appears normal when compared to the other processor data files. The processor’s performance will be degraded to the degree of M0/M1 referenced screen data. For example, if your screen has only one M0/M1 element, degradation is minimal. If your screen has 69 M0/M1 elements, degradation is significant.

Transferring Data Between Processor Files and M0 or

M1 Files

The processor does not contain an image of the M0 or M1 file. As a result, you must edit and monitor M0 and M1 file data via instructions in your ladder program. For example, you can copy a block of data from a processor data file to an M0 or M1 data file or vice versa using the COP instruction in your ladder program.

The COP instructions below copy data from a processor bit file and integer file to an M0 file. For the example, assume the data is configuration information affecting the operation of the specialty I/O module.

First scan bit. It makes this rung true only for the first scan after entering Run mode.

S:1

] [

COP

COPY FILE

Source

Dest

Length

#B3:0

#M0:1.0

COP

COPY FILE

Source

Dest

Length

#N7:0

#M0:1.16

The COP instruction below copies data from an M1 data file to an integer file. This technique is used to monitor the contents of an M0 or M1 data file indirectly, in a processor data file.

COP

COPY FILE

Source

Dest

Length

#M1:4.3

#N10:0

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M0-M1 Files and G Files

B-201

Access Time

During the program scan, the processor must access the specialty I/O card to read/write M0 or M1 data. This access time must be added to the execution time of each instruction referencing M0 or M1 data.

For the SLC 5/03 and SLC 5/04 processors, the instruction types vary in their execution times.

The following table shows approximate access times per instruction or word of data for the SLC 5/02, SLC 5/03, and SLC 5/04 processors.

Processor Instruction Type

SLC 5/02 Series B All types

SLC 5/02 Series C All types

SLC 5/03 (All

Series)

XIC or XIO

OTU, OTE, or OTL

COP to M file

COP from M file

FLL

MVM to M file any source or Destination M file address

SLC 5/04 OS400 XIC or XIO

OTU, OTE, or OTL

COP to M file

COP from M file

FLL

MVM to M file any source or Destination M file address

Access Time per Bit

Instruction or Word of Data

850

694

µ s s

1930

1160

782

925

894

730

743

879

µ s s s s s s s s

1. Except the OSR instruction and the instruction parameters noted on page C-2.

Multi-Word Instruction

1580

950

Access Time per

s plus 670 s plus 400 µ

µ s per word s per word

772

µ s plus 23

µ s per word

760

µ s plus 22

µ s per word

753

µ s plus 30

µ s per word

735 µ s plus 23 µ s per word

722 µ s plus 22 µ s per word

716 µ s plus 30 µ s per word

SLC 5/02 Processor Example

M0:2.1

] [

M1:3.1

]/[

M0:2.1

( )

If you are using a SLC 5/02 Series B processor, add 1930 µs to the program scan time for each bit instruction addressed to an M0 or M1 data file. If you are using a SLC 5/03 Series C processor, add 1160

µs.

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M0-M1 Files and G Files

COP

COPY FILE

Source

Dest

Length

#B3:0

#M0:1.0

If you are using a SLC 5/02 Series B processor, add 1580 µs plus 670

µs per word of data addressed to the M0 or M1 file. As shown above,

34 words are copied from #B3:0 to M0:1.0. Therefore, this adds

24360 µs to the scan time of the COP instruction. If you are using a

SLC 5/02 Series C processor, add 950 µs plus 400 µs per word. This adds 14550 µs to the scan time of the COP instruction.

SLC 5/03 Processor Example

COP

COPY FILE

Source

Dest

Length

#B3:0

#M0:1.0

The SLC 5/03 processor access times depend on the instruction type.

Consult the table on B-5 for the correct access times to add. As an example, if you use a COP to M file instruction like the one shown above, add 772 µs plus 23 µs per word. This adds 1554 µs to the SLC

5/03 processor scan time due to the COP instruction.

SLC 5/04 Processor Example

COP

COPY FILE

Source

Dest

Length

#B3:0

#M0:1.0

The SLC 5/04 processor access times depend on the instruction type.

Consult the table on B-5 for the correct access times to add. As an example, if you use a COP to M file instruction like the one shown above, add 735 µs plus 23 µs per word. This adds 1517 µs to the SLC

5/04 processor scan time due to the COP instruction.

Minimizing the Scan Time

You can keep the processor scan time to a minimum by economizing on the use of instructions addressing the M0 or M1 files. For example, XIC instruction M0:2.1/1 is used in rungs 1 and 2 of the figure below, adding approximately 2 ms to the scan time if you are using a SLC 5/02 Series B processor.

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M0-M1 Files and G Files

B-203

M0:2.1

] [

M0:2.1

] [

( )

XIC instructions in rungs 1 and 2 are addressed to the M0 data file. Each of these instructions adds approximately 1 ms to the scan time (SLC 5/02

Series B Processor).

In the equivalent rungs of the figure below, XIC instruction M0:2.1/1 is used only in rung 1, reducing the SLC 5/02 scan time by approximately 1 ms.

M0:2.1

] [

( )

These rungs provide equivalent operation to those of figure A by substituting XlC instruction B3/10 for XlC instruction M0:2.1/1 in rung 2.

Scan time is reduced by approximately 1ms (Series B processor).

The following figure illustrates another economizing technique. The

COP instruction addresses an M1 file, adding approximately 4.29 ms to the scan time if you are using a SLC 5/02 Series B processor. Scan time economy is realized by making this rung true only periodically, as determined by clock bit S:4/8. (Clock bits are discussed in appendix B of the SLC 500 and MicroLogix 1000 Instruction Set

Reference Manual, Publication 1747-6.15.) A rung such as this might be used when you want to monitor the contents of the M1 file, but monitoring need not be on a continuous basis.

S:4/8 causes the #M1:4.3 file to update the #N10:0 file every 2.56 seconds.

S:4

] [

B11

[OSR]

COP

COPY FILE

Source

Dest

Length

#M1:4.3

#N10:0

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M0-M1 Files and G Files

Capturing M0-M1 File Data

The first two ladder diagrams in the last section illustrate a technique allowing you to capture and use M0 or M1 data as it exists at a particular time. In the first figure, bit M0:2.1/1 could change state between rungs 1 and 2. This could interfere with the logic applied in rung 2. The second figure avoids the problem. If rung 1 is true, bit

B3/10 captures this information and places it in rung 2.

In the second example of the last section, a COP instruction is used to monitor the contents of an M1 file. When the instruction goes true, the 6 words of data in file #M1:4.3 is captured as it exists at that time and placed in file #N10.0.

Specialty I/O Modules with Retentive Memory

Certain specialty I/O modules retain the status of M0-M1 data after power is removed. See your specialty I/O module user’s manual. This means that an OTE instruction having an M0 or M1 address remains on if it is on when power is removed. A “hold-in” rung as shown below will not function as it would if the OTE instruction were nonretentive on power loss. If the rung is true at the time power is removed, the OTE instruction latches instead of dropping out. When power is again applied, the rung will be evaluated as true instead of false.

] [

M0:2.1

] [

M0:2.1

( )

ATTENTION: When used with a speciality I/O module having retentive outputs, this rung can cause unexpected start-up on powerup.

You can achieve non-retentive operation by unlatching the retentive output with the first pass bit at powerup:

S:1

] [

M0:2.1

] [

M0:2.1

(U)

M0:2.1

( )

This rung is true for the first scan after powerup to unlatch M0:2.1/1.

Publication 1747-6.22

G Files

M0-M1 Files and G Files

B-205

Some specialty I/O modules use G (configuration) files (indicated in the specific specialty I/O module user’s manual). These files can be thought of as the software equivalent of DIP switches.

The content of G files is accessed and edited offline under the I/O

Configuration function. You cannot access G files under the Monitor

File function. Data you enter into the G file is passed on to the specialty I/O module when you download the processor file and enter the REM Run or any one of the REM Test modes.

READ

CONFIG

Configuring G Files

The G file is configured as part of the I/O configuration procedure for the processor file. After you have assigned the specialty I/O module to a slot (the procedure is the same as assigning other modules except that you must specify the ID code of the specialty I/O module), the following functions appear at the bottom of the screen:

ONLINE

CONFIG

MODIFY

RACKS

MODIFY

SLOT

DELETE

SLOT

UNDEL

SLOT

EXIT

SPIO

CONFIG

This is the starting point for configuring the G file and other parameters of the specialty I/O module. Complete the following steps to create and monitor the G file:

1. Press

[F9]

, Specialty I/O Configuration. A screen similar to the following is displayed:

I/O CONFIGURATION FOR:EXAMPLE

RACK 1

RACK 2

RACK 3

1746-A4 4-SLOT Backplane

SPECIAL CONFIG FOR SLOT:

SLOT

Module's ID Code:

Maximum Input Words:

Maximum Output Words:

Scanned Input Words:

Scanned Output Words:

M0 Length:

M1 Length:

`G' File Size:

ISR Number:

ESC exits

Press a function key

ISR

NUMBER

MODIFY

G FILE

ADVNCD

SETUP

12705

G FILE

SIZE

2. Press

[F7]

, G File Size, then specify the number of words required for the specialty I/O module.

3. Press

[F3]

, Modify G File. The content of the G file appears in the display area. Data is shown in the default form, decimal:

Publication 1747-6.22

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M0-M1 Files and G Files address 0 1 2 3 4 5 6 7 8 9

G1:0 xxxx 0 0 0 0 0 0 0 0 0

G1:10 0 0 0 0 0 0

The function keys appearing below the data table indicate the three data formats available to you - binary data, decimal data, and hex/bcd data:

BINARY

DATA

DECIMAL

DATA

HEX/BCD

DATA

The following figure illustrates the three G file data formats that you can select. Word addresses begin with the file identifier G and the slot number you have assigned to the specialty I/O module. In this case, the slot number is 1. Sixteen words have been created

(addresses G1:0 through G1:15).

16-word G file, I/O slot 1, decimal format

address 0 1 2 3 4 5 6 7 8 9

G1:0 xxxx 0 0 0 0 0 0 0 0 0

G1:10 0 0 0 0 0 0

16-word G file, I/O slot 1, hex/bcd format

address 0 1 2 3 4 5 6 7 8 9

G1:0 xxxx 0000 0000 0000 0000 0000 0000 0000 0000 0000

G1:10 0000 0000 0000 0000 0000 0000

16-word G file, I/O slot 1, binary format

address 15 data 0

G1:0 xxxx xxxx xxxx xxxx

G1:1 0000 0000 0000 0000

G1:2 0000 0000 0000 0000

G1:3 0000 0000 0000 0000

G1:4 0000 0000 0000 0000

G1:5 0000 0000 0000 0000

G1:6 0000 0000 0000 0000

G1:7 0000 0000 0000 0000

G1:8 0000 0000 0000 0000

G1:9 0000 0000 0000 0000

G1:10 0000 0000 0000 0000

G1:11 0000 0000 0000 0000

G1:12 0000 0000 0000 0000

G1:13 0000 0000 0000 0000

G1:14 0000 0000 0000 0000

G1:15 0000 0000 0000 0000

Editing G File Data

Data in the G file must be edited according to your application and the requirements of the specialty I/O module. You edit the data offline under the I/O configuration function only. With the decimal and hex/bcd formats, you edit data at the word level:

• G1:1 = 234 (decimal format)

G1:1 = 00EA (hex/bcd format)

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M0-M1 Files and G Files

B-207

With the binary format, you edit data at the bit level:

• G1/19 = 1

Important:

Word 0 of the G file is configured automatically by the processor according to the particular specialty I/O module.

Word 0 cannot be edited.

Publication 1747-6.22

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M0-M1 Files and G Files

Publication 1747-6.22

Appendix

RIO Configuration Worksheet

This appendix provides a worksheet to help you configure your RIO devices.

Directions

We recommend that you use a photocopy of the worksheet so you retain a blank worksheet for future applications.

SLC Processor Input Image

Bit Number-Decimal

Logical

Rack 0

Logical

Rack 1

Logical

Rack 2

Logical

Rack 3

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 24

Group 25

Group 26

Group 27

Group 28

Group 29

Group 30

Group 31

High Byte

8 7

Low Byte

I:e.19

I:e.20

I:e.21

I:e.22

I:e.23

I:e.24

I:e.25

I:e.0

I:e.9

I:e.10

I:e.11

I:e.12

I:e.13

I:e.14

I:e.15

I:e.1

I:e.2

I:e.3

I:e.4

I:e.5

I:e.6

I:e.7

I:e.8

I:e.16

I:e.17

I:e.18

I:e.26

I:e.27

I:e.28

I:e.29

I:e.30

I:e.31

Logical

Rack 0

Logical

Rack 1

Logical

Rack 2

Logical

Rack 3

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 24

Group 25

Group 26

Group 27

Group 28

Group 29

Group 30

Group 31

SLC Processor Output Image

High Byte

8 7

Low Byte

O:e.18

O:e.19

O:e.20

O:e.21

O:e.22

O:e.23

O:e.24

O:e.25

O:e.0

O:e.1

O:e.2

O:e.3

O:e.4

O:e.5

O:e.6

O:e.7

O:e.8

O:e.9

O:e.10

O:e.11

O:e.12

O:e.13

O:e.14

O:e.15

O:e.16

O:e.17

O:e.26

O:e.27

O:e.28

O:e.29

O:e.30

O:e.31

Publication 1747-6.22

C-210

SLC Processor Input Image

Bit Number-Decimal

Logical

Rack 0

Logical

Rack 1

Logical

Rack 2

Logical

Rack 3

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 24

Group 25

Group 26

Group 27

Group 28

Group 29

Group 30

Group 31

High Byte

Low Byte

8 7 0

I:e.24

I:e.25

I:e.26

I:e.27

I:e.28

I:e.29

I:e.30

I:e.15

I:e.16

I:e.17

I:e.18

I:e.19

I:e.20

I:e.21

I:e.22

I:e.23

I:e.31

I:e.7

I:e.8

I:e.9

I:e.10

I:e.11

I:e.12

I:e.13

I:e.14

I:e.0

I:e.1

I:e.2

I:e.3

I:e.4

I:e.5

I:e.6

SLC Processor Output Image

Bit Number-Decimal

Logical

Rack 0

Logical

Rack 1

Logical

Rack 2

Logical

Rack 3

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 24

Group 25

Group 26

Group 27

Group 28

Group 29

Group 30

Group 31

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

Group 0

Group 1

Group 2

Group 3

Group 4

Group 5

Group 6

Group 7

High Byte

Low Byte

7 0

O:e.17

O:e.18

O:e.19

O:e.20

O:e.21

O:e.22

O:e.23

O:e.24

O:e.9

O:e.10

O:e.11

O:e.12

O:e.13

O:e.14

O:e.15

O:e.16

O:e.0

O:e.1

O:e.2

O:e.3

O:e.4

O:e.5

O:e.6

O:e.7

O:e.8

O:e.25

O:e.26

O:e.27

O:e.28

O:e.29

O:e.30

O:e.31

Publication 1747-6.22

Glossary

The following terms are used throughout this manual. Refer to the Allen-Bradley

Industrial Automation Glossary, Publication Number AG-7.1, for a complete guide to Allen-Bradley technical terms.

Adapter

−

Any physical device that is a slave on the RIO link.

Adapter Image

−

That portion of the scanner image assigned to an individual adapter.

ASB Module

−

The Catalog Number 1747-ASB, 1771-ASB, or 1794-ASB

Remote I/O Adapter Module. The ASB module is an adapter.

ASB Module Chassis

−

The chassis directly controlled by the ASB module. This includes the remote chassis and (if installed) two remote expansion chassis when using the 1747-ASB.

Block Transfer (BT)

−

See RIO Block Transfer.

Block Transfer Read (BTR)

−

A form of block transfer that occurs when a remote device transfers data to the SLC processor.

Block Transfer Write (BTW)

−

A form of block transfer that occurs when the

SLC processor transfers data to a remote device.

Complementary I/O

−

Functionality that allows you to maximize I/O usage by pairing up I/O data from a primary and complementary chassis.

Discrete I/O

−

An input or output device that has corresponding bit locations in the scanner’s input or output file.

Discrete I/O Module

−

An I/O module used to sense or control two–state (ON/

OFF) devices.

Data Transfer Control Word (DTCW)

−

This word is M0:s.3410 (where s=slot number of the BSN) and is used by the primary processor to initiate data transfers to the primary BSN. Eventually the primary processor initiates data transfers to the secondary BSN over the HSSL, and then to the secondary processor.

Data Transfer Handshake Word (DTHW)

−

This word is M0:S.3411 (where s=slot number of BSN) and is used by the secondary processor to inform the secondary BSN that it has received the latest data block and is ready for the next data block.

Data Transfer Status Word (DTSW)

−

This word is M1:s.3410 (where s=slot number of BSN and is used in both the primary and secondary systems to affect the transfer of data on the HSSL.

212

Glossary

Extended Node Capability

−

Functionality that allows you to use an

82 Ohm termination resistor at both ends of the RIO link for all baud rates. This functionality also allows for up to 32 adapters to be connected to the RIO link.

G file

−

The SLC file used to configure the scanner. You enter configuration information into this file during SLC processor programming. This file is loaded to the scanner by the SLC processor upon entering run mode.

High-Speed Serial Link (HSSL)

−

2 Mbit/second link between primary and secondary BSN modules to provide the secondary SLC processor with input, block transfer, and user retentive data. Network status and control information are also transferred between BSN modules on this link.

Inhibit

−

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

Input file

−

The scanner’s input image file that is updated during the

SLC processor input scan.

Local Expansion Chassis

−

A chassis that is connected to a local

SLC chassis using a 1747-C9 (91.4 cm [36 in.]) or 1747-C7 (15.2 cm

[6 in.]) cable.

Local SLC Chassis

−

The chassis that contains the SLC processor and scanner.

Logical Device

−

Any portion of a logical rack that is assigned to a single adapter. Adapters may appear as more than one 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.

Logical Rack

−

A fixed section of the scanner image comprised of eight input image words and eight output image words.

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.

M files

−

The SLC M0 and M1 data files that reside in the scanner. M files contain RIO network status (M1) and control (M0) information.

The contents of these files can be directly accessed by your application program. Also, the M files are used to control and monitor

RIO block transfer operations.

Publication 1747-6.22

Glossary

213

Module Status Word (MSW)

−

This word is M1:s.3401 (where s=slot number of the BSN) and is used to monitor the status of the

1747-BSN itself and its counterpart in the remote system.

Output file

−

The scanner’s output file that is updated during the

SLC processor output scan.

Remote Chassis

−

The chassis containing an ASB module and connected to the local SLC chassis via the RIO link.

Remote Expansion Chassis

−

A chassis that is connected to a remote chassis using a 1747-C9 (91.4 cm [36 in.]) or 1747–C7

(15.2 cm [6 in.]) cable.

Reset, Adapter Decide

−

Commands sent by the scanner to a logical device during an RIO discrete transfer. These commands instruct the logical device to reset all of its discrete outputs if hold last state is not selected, or to hold all of its discrete outputs in their last state if hold last state is selected.

Reset, Adapter Reset

−

Commands sent by the scanner to a logical device during an RIO discrete transfer. These commands instruct the logical device to reset all of its discrete outputs, regardless of the hold last state selection.

RIO Block Transfer

−

The exchange of up to 64 words of data between the scanner and a remote device. RIO block transfers only occur if you program them in your processor control program.

RIO Discrete Transfer

−

The exchange of image data between the scanner and adapter. RIO discrete transfers occur continuously whenever the scanner and adapter are communicating on the RIO link.

RIO Link

−

An Allen-Bradley communication system supporting high-speed serial transfer of Remote I/O (RIO) control information.

This link consists of one master and one or more slaves.

RIO Link Device

−

Refers to any Allen-Bradley or licensed third party product that connects to the RIO link as an adapter or slave device.

Scanner

−

The Catalog Number 1747-SN, Remote I/O Scanner, which is the master on the RIO network.

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 processor image.

Publication 1747-6.22

214

Glossary

SLC Chassis

−

A physical SLC rack that houses SLC processors and

1746 and 1747 I/O modules.

SLC Processor

−

The processor that controls the SLC chassis in which the scanner is installed.

Slot

−

The physical location in any SLC chassis used to insert I/O modules.

Specialty I/O Module

−

An I/O module other than a discrete I/O module (e.g., an analog module).

System Status Word (SSW)

−

This word is M1:s.3400 (where s=slot number of BSN and is used to monitor the status of the entire backup system.

Publication 1747-6.22

Index

Numerics

1/2-slot addressing

, 1-13,

5-28

1-slot addressing

, 1-12, 5-28

2-slot addressing

, 1-11, 5-28,

7-7

Access-point address

, 4-4

Active device status

, 5-22

Adapter

, G-1

Adapter image

, 1-3, G-1

Advanced Setup menu

, 2-3

Agency certification

, A-1

ASB module

, G-1

ASB module chassis

, G-1

Asynchronized data transfer

4-6

Automatic transfer

, 4-1

Backplane communication

4-2

Backplane current consumption

, A-1

Backplane power requirements

, 1-3

Baud rate

, 3-1

Baud rate selection

, A-1

Baud rate settings

, 1-18, 3-2

Bit displacement instructions

9-18

Block transfer

, 1-8, 1-16, 4-2,

5-11, 7-1, G-1 block transfer throughput

, A-9

Block transfer buffer layout

7-3

Block transfer buffers

, 7-5,

7-8

Block transfer failure

, 7-16

Block transfer instructions

9-19

Block transfer modules

, 1-14

Block transfer read

, 7-1, 7-2,

7-3, G-1

Block transfer write

, 7-1, 7-2,

7-4, G-1

capturing M0-M1 file data

B-7

Carrier detect circuit

, 8-7

Code ID number

, 5-29

Communications attempted status bit

, 5-20

Compare instructions

, 9-18

Compatible devices

, 1-9

Complementary chassis

, 1-10

Complementary device

, 5-8

Complementary I/O

, 1-9, 1-

11, 1-12, 1-13, 1-16, 5-5,

G-1

Complementary mode

, 5-3

Configuration DIP switch

2-2, 3-1

Configuring complementary

I/O

, 1-10

Control buffer layout

, 7-9

Control file

, 5-10

Control flag definitions

, 7-9

Counter instructions

, 9-17

Data block counters

, 6-14

Data Highway Plus switching

8-1, 8-4, 8-5

Data table transfer time

, 8-2

Data transfer

, 1-22

Data transfer control word

4-6, 6-5, 6-6, G-1

Data transfer handshake word

4-6, 6-6, 6-8, G-1

Data transfer status word

, 4-6,

Publication 1747-6.22

I-ccxvi

Index

6-5, 6-7, G-1 definitions

, G-1

Device fault status

, 5-14, 5-23

Device inhibit

, 5-13

Device reset

, 5-13

Device reset words

, 5-17

DH+ communication

, 6-4

DH+ smart switch

, 8-4

Diagnostic instructions

, 9-18

Dip switch settings

, 1-18

Discrete I/O

, G-1

Discrete I/O module

, G-1 discrete I/O throughput with block transfers present example

, A-7 discrete I/O throughput without block transfers present example

, A-4

Discrete I/O transfer

, 1-4

Enabled device fault status bit

5-19

Extended node capability

, 1-9,

3-6, A-1, G-2

FIFO instructions

, 9-18

File Arithmetic instructions

9-18

File Copy instructions

, 9-18

File Search instructions

, 9-18

G file

, 5-2, 5-5, 5-7, 5-9,

5-21, G-2 editing G file data

, B-10

High byte

, 5-2, 7-6

High-speed serial link

, 1-1,

1-22, 4-1, 6-2, 6-4, G-2

Hold last state

, 5-16

HSSL wiring

, 3-5

I/O image data

, 1-3

Inhibit

, G-2

Input file

, G-2

Input image data

, 5-1

Input image file

, 1-5

Input signal update time

, 8-2

Input/status buffers

, 7-9

Internal watchdog timeout

8-4

Local expansion chassis

, G-2

Local serial link

, 1-1

Local SLC chassis

, G-2

Local status link

, 1-22, 6-2,

6-4

Local status link wiring

, 3-5

Logic instructions

, 9-18

Logical device

, 1-4, G-2

Logical device address

, 5-3,

5-26

Logical group

, 1-3, G-2

Logical groups

, 5-1, 5-2, 5-5

Logical image size

, 5-3

Logical rack

, G-2

Logical racks

, 1-3, 5-1, 5-2,

5-5, 5-9

Logical slot

, G-2

Logical specifications

, 1-9

Logical words

, 5-1, 5-2

Loosely synchronized backup

8-3

Low byte

, 5-2, 7-6

M files

, G-2

M0 and M1 data files capturing M0-M1 file data

, B-7

Publication 1747-6.22

Index I-ccxvii minimizing the scan time

B-6 specialty I/O modules with retentive memory

, B-8

M0 file

, 6-5, 7-5

M0 files

, 5-10

M1 file

, 6-5, 7-3

M1 files

, 5-10

Message instructions

, 9-19

Module address switch

, 1-19,

3-2

Module status word

, 4-5, 6-4,

6-9, 6-13, G-3

Noise immunity

, A-1

Operating temperature

, A-1

Output delay time

, A-11

Output file

, G-3

Output image file

, 1-5

Physical specifications

, 1-9

PID instructions

, 9-20

Primary chassis

, 1-10

Primary device

, 5-7

Primary mode

, 5-3, 6-4, 6-5

Primary module

, 1-1

Primary system

, 1-22, 6-2,

6-5, 6-6

Processor fault

, 6-2, 6-5

Receiver program

, 4-5

Remote chassis

, G-3

Remote expansion chassis

G-3

Remote I/O link

, 6-2

Remote I/O switching

, 8-1

Remote output reset

, 5-13

Remote output reset words

5-17

Remote programming

, 4-4

Reserve current capacity

, 3-3

Reset, adapter decide

, G-3

Reset, adapter reset

, G-3

Retentive memory

, B-8

RIO block transfer

, 7-1, G-3

RIO communication

, 6-5

RIO discrete transfer

, G-3

RIO link

, G-3

RIO link device

, G-3

RIO link wiring

, 3-5

RIO scan time throughput

, A-4

RIO/DH+ Communication

Channel

, 4-2

Scanner

, G-3 scanner output delay time with block transfer,

A-6 without block transfer, A-11

Scanner asynchronous operation

, 1-5

Scanner image

, G-3

Secondary mode

, 6-4, 6-5

Secondary module

, 1-1

Secondary system

, 1-22, 6-3,

6-5, 6-6

Sequencing instructions

, 9-18

SLC chassis

, G-4

SLC processor

, G-4

Specialty I/O Configuration menu

, 2-3

Specialty I/O module

, G-4

Starting group address

, 5-14

Status file

, 5-10

Status flag definitions

, 7-11

Publication 1747-6.22

I-ccxviii

Index

Status LEDs

, 1-17, 3-6

Storage temperature

, A-1

Switch assemblies status word

6-12

Switchover diagnostic

, 6-3

System status word

, 4-5, 6-2,

6-9, G-4

Terminal wiring

, 3-4 terms

, G-1 throughput

, A-2 calculating throughput

A-3 block transfer, A-9 with block transfers present, A-6,

A-10 without block transfers present,

A-3 introduction

, A-2

Timer byte

, 9-17

Timer instructions

, 9-16

Timing diagrams

, 7-14

Total switchover time

, 8-1

Transmitter program

, 4-5

Publication 1747-6.22

Index I-ccxix

Publication 1747-6.22

Publication 1747-6.22 — October 1999

Key Features

Provides redundancy for Remote I/O (RIO), RS232 channel switchover, and DH+
Supports complementary I/O for increased I/O capacity
Offers high-speed serial link (HSSL) for data transfer between primary and secondary processors
Includes local serial link (LSL) for communication between multiple BSN modules
Features extended node capability for connecting up to 32 physical devices on an RIO link

Frequently asked questions

What is the purpose of the 1747-BSN Backup Scanner Module?

The 1747-BSN Backup Scanner Module provides redundancy for Remote I/O (RIO), RS232 channel switchover, and DH+ communications. It also provides a High Speed Serial Link (HSSL) for transferring data between primary and secondary processors.

How does the 1747-BSN Backup Scanner Module work?

The 1747-BSN Backup Scanner Module operates by continuously scanning the adapters on the RIO link. It also provides a backup system that automatically takes over control in the event of a fault in the primary system.

What are the benefits of using the 1747-BSN Backup Scanner Module?

Using the 1747-BSN Backup Scanner Module enhances system reliability and uptime by providing redundancy for critical components. It also simplifies system configuration and management by providing a centralized point of control for remote I/O.

What are the compatibility requirements for the 1747-BSN Backup Scanner Module?

The 1747-BSN Backup Scanner Module is compatible with Allen-Bradley SLC 500 processors and other compatible devices, such as 1746 I/O chassis and PanelView operator terminals.