Rockwell Automation DAG6.5.8 User Manual

SCADA System

Application Guide

Important User Information

Solid state equipment has operational characteristics differing from those of electromechanical equipment. Safety Guidelines for the Application, Installation and Maintenance of Solid State Controls (Publication SGI-1.1

available from your local Rockwell Automation http://www.ab.com/manuals/gi) describes some important differences between solid state equipment and hard-wired electromechanical devices. Because of this difference, and also because of the wide variety of uses for solid state equipment, all persons responsible for applying this equipment must satisfy themselves that each intended application of this equipment is acceptable.

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

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

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

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

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

sales office or online at

WARNING

IMPORTANT

ATTENTION

SHOCK HAZARD

BURN HAZARD

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

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

Identifies information about practices or circumstances that can lead to personal injury or death, property damage, or economic loss. Attentions help you:

• identify a hazard

• avoid a hazard

• recognize the consequence

Labels may be located on or inside the drive to alert people that dangerous voltage may be present.

Labels may be located on or inside the drive to alert people that surfaces may be dangerous temperatures.

Summary of Changes

The information below summarizes the changes to this manual since the last printing.

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

For information on See

Removing Configuring Classic PLC-5 Processors with 1785-KE Modules chapter

Add in additional publications Preface Designing communication for DF1 Radio Modem 1-17 through 1-19 Modbus RTU 3-46 through 3-57 Data Logging 3-58 through 3-69 Conditions that will erase the data retrieval file 3-69 DF1 Radio Modem 4-7 through 4-8 Configuring a Radio Modem station 4-27 through 4-32 Rockwell Automation modems 8-3 through 8-4 Configuring modems for PLC-5, SLC, and Logix processors 10-3 Configuring modems for MicroLogix 1100/1200/1500

controllers Communicating over the telephone line 10-4 through 10-8 Remotely programming Allen-Bradley processors over a

telemetry network DF1 Radio Modem B-7 Third party suppliers Appendix C

10-4

Chapter 11

1 Publication AG-UM008C-EN-P - February 2005

2 Summary of Changes

Publication AG-UM008C-EN-P - February 2005

Designing Communication

Preface

What SCADA Information Is Available?. . . . . . . . . . . . . . . . 1-1

Audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Contents of this Manual. . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Terms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Address Conventions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Related Publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Chapter 1

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

Choosing a Polling Mode for DF1 Half-Duplex Master . . . . 1-2

Message-Based Polling Mode . . . . . . . . . . . . . . . . . . . . 1-2

Standard Polling Mode . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

About Polled Report-by-Exception . . . . . . . . . . . . . . . . 1-4

About Slave-to-Slave Messaging . . . . . . . . . . . . . . . . . . 1-5

Addressing Tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Communication Scheme Design Using Standard-Mode . . . . 1-8

Designing a Polling Scheme . . . . . . . . . . . . . . . . . . . . 1-11

Planning for Timing Issues . . . . . . . . . . . . . . . . . . . . . 1-13

Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . 1-13

Communication Scheme Design Using

Message-Based Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15

Designing Communication

for DF1 Full-Duplex Protocol. . . . . . . . . . . . . . . . . . . . . . . 1-16

Designing Communication for DF1 Radio Modem Protocol. 1-17

Determining When to Use DF1 Radio Modem Protocol . 1-17

What to Do Next? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-19

Chapter 2

Configuring Enhanced PLC-5 Processors

1 Publication AG-UM008C-EN-P - February 2005

Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Installing the Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Configuring a DF1 Half-Duplex Standard Mode

Master Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Define the Communication Driver Characteristics . . . . . 2-5

Displaying System (Master) Channel Status . . . . . . . . . . 2-7

Create Station Lists. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Monitor Active Stations . . . . . . . . . . . . . . . . . . . . . . . . 2-10

Configuring a DF1 Half-Duplex Message-based

Mode Master Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11

Configuring the Processor as a Slave Station. . . . . . . . . . . . 2-15

Displaying Slave System Channel Status . . . . . . . . . . . . 2-18

2 Table of Contents

Configuring MicroLogix 1100/1200/1500 Controllers

Configuring the Processor as a Station on a

Point-to-Point Link . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20

Displaying Point-to-Point System Channel Status . . . . . . 2-22

Messaging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23

Master Station to Slave Station . . . . . . . . . . . . . . . . . . . 2-23

Polled Report-by-Exception . . . . . . . . . . . . . . . . . . . . . 2-23

Processor-to-Processor . . . . . . . . . . . . . . . . . . . . . . . . . 2-24

Considerations When Configuring MSG Control Blocks . 2-25

Example MSG Control Blocks. . . . . . . . . . . . . . . . . . . . 2-26

Chapter 3

Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Installing the Controller. . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

MicroLogix 1200/1500 Channel 0 Cable Pinouts - User

Supplied Optical Isolator . . . . . . . . . . . . . . . . . . . . . . . 3-3

MicroLogix 1200/1500 Channel 0 Cable Pinouts -

Allen-Bradley Supplied Optical Isolator. . . . . . . . . . . . . 3-4

MicroLogix 1500 LRP Channel 1 Cable Pinouts . . . . . . . 3-5

Using Modems that Support DF1 Communication Protocols 3-6

Dial-up Phone Modems . . . . . . . . . . . . . . . . . . . . . . . . 3-6

Leased-Line Modems . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

Radio Modems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

Line Drivers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

Modem Control Line Operation . . . . . . . . . . . . . . . . . . . . . 3-8

DF1 Full-Duplex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8

DF1 Half-Duplex Slave. . . . . . . . . . . . . . . . . . . . . . . . . 3-8

DF1 Half Duplex Master. . . . . . . . . . . . . . . . . . . . . . . . 3-9

DF1 Radio Modem. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

Configuring DF1 Half-Duplex Channel 0 Parameters. . . . . . 3-11

RTS Send Delay and RTS Off Delay . . . . . . . . . . . . . . . 3-11

Configuring a Standard-Mode DF1 Half-Duplex

Master Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12

Minimum DF1 Half-Duplex Master Channel 0

ACK Timeout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14

Determining Minimum Master ACK Timeout . . . . . . . . . 3-15

DF1 Half-Duplex Master Channel Status . . . . . . . . . . . . 3-17

Monitor Active Stations. . . . . . . . . . . . . . . . . . . . . . . . . 3-18

Configuring a Message-based Mode DF1

Half-Duplex Master Station . . . . . . . . . . . . . . . . . . . . . . . . 3-19

Configuring a Slave Station . . . . . . . . . . . . . . . . . . . . . . . . 3-22

Configuring Poll Timeout . . . . . . . . . . . . . . . . . . . . . . . . . 3-25

DF1 Half-Duplex Slave Channel Status . . . . . . . . . . . . . 3-25

Configuring a Radio Modem Station. . . . . . . . . . . . . . . . . . 3-27

DF1 Radio Modem Channel Status . . . . . . . . . . . . . . . . 3-30

Configuring the Store & Forward Table. . . . . . . . . . . . . 3-31

Publication AG-UM008C-EN-P - February 2005

Table of Contents 3

Configuring a Station on a Point-to-Point Link . . . . . . . . . . 3-33

DF1 Full-Duplex Channel Status . . . . . . . . . . . . . . . . . . 3-35

DF1 Messaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-36

Master Station to Slave Station . . . . . . . . . . . . . . . . . . . 3-36

Polled Report-by-Exception . . . . . . . . . . . . . . . . . . . . . 3-36

Processor-to-Processor . . . . . . . . . . . . . . . . . . . . . . . . . 3-37

Considerations When Configuring MSG

Control Blocks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37

Example MSG Control Blocks . . . . . . . . . . . . . . . . . . . . . . 3-42

Modbus RTU Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-46

Modbus RTU Master. . . . . . . . . . . . . . . . . . . . . . . . . . . 3-46

Modbus RTU Slave. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-47

Modbus RTU Master Configuration . . . . . . . . . . . . . . . . 3-48

Modbus RTU Master Configuration . . . . . . . . . . . . . . . . 3-49

Modbus RTU Slave Configuration . . . . . . . . . . . . . . . . . 3-50

Modbus Slave Memory Map . . . . . . . . . . . . . . . . . . . . . 3-51

Modbus Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-53

Modbus Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . 3-54

Configuring a Modbus Message . . . . . . . . . . . . . . . . . . 3-56

Data Logging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-58

Queues and Records . . . . . . . . . . . . . . . . . . . . . . . . . . 3-58

Example Queue 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-59

Example Queue 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-60

Configuring Data Log Queues . . . . . . . . . . . . . . . . . . . 3-62

DLG - Data Log Instruction. . . . . . . . . . . . . . . . . . . . . . 3-64

Data Log Status File . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-64

Retrieving (Reading) Records . . . . . . . . . . . . . . . . . . . . 3-66

Accessing the Retrieval File . . . . . . . . . . . . . . . . . . . . . 3-67

Retrieval Tools. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-67

Information for Creating Your Own Application . . . . . . 3-68

Conditions that Will Erase the Data Retrieval File . . . . . . . . 3-69

Configuring SLC 5/03, 5/04, and 5/05 Processors

Chapter 4

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

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

Installing the Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

Using Modems that Support DF1 Communication Protocols 4-3

Dial-up Phone Modems . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Leased-Line Modems . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Radio Modems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Line Drivers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Modem Control Line Operation . . . . . . . . . . . . . . . . . . . . . 4-5

DF1 Full-Duplex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

DF1 Half-Duplex Slave. . . . . . . . . . . . . . . . . . . . . . . . . 4-6

DF1 Half Duplex Master. . . . . . . . . . . . . . . . . . . . . . . . 4-6

DF1 Radio Modem. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7

Publication AG-UM008C-EN-P - February 2005

4 Table of Contents

Configuring DF1 Half-Duplex Channel 0 Parameters. . . . . . 4-8

RTS Send Delay and RTS Off Delay . . . . . . . . . . . . . . . 4-8

Configuring a Standard-Mode DF1 Half-Duplex

Master Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10

Minimum DF1 Half-Duplex Master Channel 0

ACK Timeout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13

Determining Minimum Master ACK Timeout . . . . . . . . . 4-14

DF1 Half-Duplex Master Channel Status . . . . . . . . . . . . 4-16

Monitor Active Stations. . . . . . . . . . . . . . . . . . . . . . . . . 4-17

Configuring a Message-based Mode DF1 Half-Duplex

Master Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18

Configuring a Slave Station . . . . . . . . . . . . . . . . . . . . . . . . 4-22

Configuring Channel 0 Poll Timeout . . . . . . . . . . . . . . . . . 4-25

DF1 Half-Duplex Slave Channel Status . . . . . . . . . . . . . 4-25

Configuring a Radio Modem Station. . . . . . . . . . . . . . . . . . 4-27

DF1 Radio Modem Channel Status . . . . . . . . . . . . . . . . 4-30

Configuring the Store & Forward Table. . . . . . . . . . . . . 4-31

Configuring a Station on a Point-to-Point Link . . . . . . . . . . 4-33

DF1 Full-Duplex Channel Status . . . . . . . . . . . . . . . . . . 4-35

Messaging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-37

Master Station to Slave Station . . . . . . . . . . . . . . . . . . . 4-37

Polled Report-by-Exception . . . . . . . . . . . . . . . . . . . . . 4-37

Processor-to-Processor . . . . . . . . . . . . . . . . . . . . . . . . . 4-38

Considerations When Configuring MSG

Control Blocks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-38

Example MSG Control Blocks . . . . . . . . . . . . . . . . . . . . . . 4-43

Configuring SLC 500 Processors with 1747-KE Interface Modules

Publication AG-UM008C-EN-P - February 2005

Chapter 5

Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

Installing the Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

Installing the 1747-KE

Interface Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

Configuring the Processor . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

Configuring the 1747-KE

Interface Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

Prepare to Configure the Driver . . . . . . . . . . . . . . . . . . 5-4

Configure the DF1 Protocol Driver . . . . . . . . . . . . . . . . 5-7

Save the Configuration. . . . . . . . . . . . . . . . . . . . . . . . . 5-10

Messaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11

Polled Report-by-Exception . . . . . . . . . . . . . . . . . . . . . 5-11

Processor-to-Processor . . . . . . . . . . . . . . . . . . . . . . . . . 5-12

Considerations When Configuring MSG Control Blocks . 5-12

Example MSG Control Blocks. . . . . . . . . . . . . . . . . . . . 5-13

Configuring MicroLogix 1000 Controllers

Table of Contents 5

Chapter 6

Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2

Installing the Controller. . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3

Isolated Connections . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4

Automatic Protocol Switching . . . . . . . . . . . . . . . . . . . . . . 6-4

Using Modems that Support DF1 Communication Protocols 6-5

Dial-up Phone Modems . . . . . . . . . . . . . . . . . . . . . . . . 6-6

Leased-Line Modems . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6

Radio Modems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6

Line Drivers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7

Modem Control Line Operation . . . . . . . . . . . . . . . . . . . . . 6-7

DF1 Full-Duplex Operation . . . . . . . . . . . . . . . . . . . . . 6-7

DF1 Half-Duplex Slave Operation. . . . . . . . . . . . . . . . . 6-7

DF1 Slave on a Multi-drop Link . . . . . . . . . . . . . . . . . . 6-8

Ownership Timeout. . . . . . . . . . . . . . . . . . . . . . . . . . . 6-9

Configuring a Slave Station . . . . . . . . . . . . . . . . . . . . . . . . 6-10

Configuring RTS Send Delay and RTS Off Delay. . . . . . . . . 6-11

Configuring Poll Timeout . . . . . . . . . . . . . . . . . . . . . . . . . 6-12

Configuring a Point-to-Point Station . . . . . . . . . . . . . . . . . . 6-13

Messaging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-14

Polled Report-by-Exception . . . . . . . . . . . . . . . . . . . . . 6-15

Processor-to-Processor . . . . . . . . . . . . . . . . . . . . . . . . . 6-15

Considerations When Configuring MSG Control Blocks . 6-16

Configuring MSG Block Message Timeout. . . . . . . . . . . 6-17

Example MSG Control Blocks. . . . . . . . . . . . . . . . . . . . 6-18

Configuring Logix Controllers

Chapter 7

Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

Installing the Controller. . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

Using Modems that Support DF1 Communication Protocols 7-3

Dial-up Phone Modems . . . . . . . . . . . . . . . . . . . . . . . . 7-4

Leased-Line Modems . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4

Radio Modems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4

Line Drivers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5

Configuring the Controller to Use the Serial Port . . . . . . . . 7-5

Modem Control Line Operation . . . . . . . . . . . . . . . . . . . . . 7-7

No Handshake Selected . . . . . . . . . . . . . . . . . . . . . . . . 7-7

Full-Duplex Selected . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7

Half-Duplex Selected with Continuous Checked . . . . . . 7-7

Half-Duplex Selected with Continuous Carrier

Unchecked . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7

Configuration Considerations for RTS Send and Off Delays. 7-8

Publication AG-UM008C-EN-P - February 2005

6 Table of Contents

Configuring a Standard-Mode DF1 Half-Duplex

Master Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8

Configuring a Master Station for Standard Polling Mode . . . 7-9

Minimum DF1 Half-Duplex Master ACK Timeout . . . . . 7-11

Determining Minimum Master Serial Port ACK Timeout . 7-12

DF1 Half-Duplex Master Diagnostic Counter . . . . . . . . . . . 7-13

Create Polling List(s) . . . . . . . . . . . . . . . . . . . . . . . . . . 7-15

Monitor Active Stations. . . . . . . . . . . . . . . . . . . . . . . . . 7-16

Configuring a Message-Based Mode DF1 Half-Duplex

Master Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-16

Configuring a Master Station for Message-based

Polling Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-17

Configuring the Controller as a Slave Station . . . . . . . . . . . 7-19

Configuring Slave Poll Timeout . . . . . . . . . . . . . . . . . . . . . 7-20

DF1 Half-Duplex Slave Diagnostic Counters. . . . . . . . . . . . 7-20

Configuring the Controller as a Station on a

Point-to-Point Link . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-22

DF1 Point-to-Point Diagnostic Counters . . . . . . . . . . . . . . . 7-24

Accessing DF1 Diagnostic Counters . . . . . . . . . . . . . . . . . . 7-25

Messaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-28

Master Station to Slave Station . . . . . . . . . . . . . . . . . . . 7-28

Polled Report-by-Exception . . . . . . . . . . . . . . . . . . . . . 7-28

Controller-to-Controller . . . . . . . . . . . . . . . . . . . . . . . . 7-29

Considerations When Configuring MSG Control Blocks . 7-30

Example MSG Control Blocks . . . . . . . . . . . . . . . . . . . . . . 7-31

Logix Controller Error Codes for PLC and SLC Messages . . . 7-38

Configuring Modems

Publication AG-UM008C-EN-P - February 2005

Chapter 8

Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1

Installing a Modem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1

Configuration Tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2

Telephone Modem Configurations . . . . . . . . . . . . . . . . . . . 8-2

Rockwell Automation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

DATA-LINC Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5

DLM4300. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5

LLM1000-2 and LLM1000-4 . . . . . . . . . . . . . . . . . . . . . . 8-6

DLM4000. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-9

DLM4100-SLC and DLM4100-PLC . . . . . . . . . . . . . . . . . 8-10

Miille Applied Research Company, Inc. (MARC) . . . . . . . . . 8-11

MARC Model 166-101. . . . . . . . . . . . . . . . . . . . . . . . . . 8-12

MARC Model 137-001. . . . . . . . . . . . . . . . . . . . . . . . . . 8-14

MARC Model 148-001. . . . . . . . . . . . . . . . . . . . . . . . . . 8-16

MARC Model 166-100. . . . . . . . . . . . . . . . . . . . . . . . . . 8-18

MARC Model 166-010. . . . . . . . . . . . . . . . . . . . . . . . . . 8-20

Radio Modem Configurations. . . . . . . . . . . . . . . . . . . . . . . 8-21

Configuring RSLinx Classic Software for DF1 Half-Duplex Communications

Table of Contents 7

DATA-LINC Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-23

SRM6000/6100/6200E. . . . . . . . . . . . . . . . . . . . . . . . . . 8-23

SRM6000/6100/6200E-SLC . . . . . . . . . . . . . . . . . . . . . . 8-25

SRM6000/6100/6200E-PLC . . . . . . . . . . . . . . . . . . . . . . 8-27

Electronic Systems

Technology (ESTeem) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-29

Microwave Data Systems (MDS). . . . . . . . . . . . . . . . . . . . . 8-35

MDS Model 2100 and 4100 Master Stations . . . . . . . . . . 8-36

MDS Model 2310 and 4310 Remote Stations . . . . . . . . . 8-37

MDS Model 9810 Spread Spectrum . . . . . . . . . . . . . . . . 8-38

Power Line Modem

Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-39

DATA-LINC Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-39

LCM100 Line Carrier Modem . . . . . . . . . . . . . . . . . . . . 8-39

Chapter 9

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

Configuring RSLinx Classic Version 2.x as a Master Station . 9-1 Configuring RSLinx Classic Version 2.x as a Slave Station . . 9-10

Using Dial-up Telephone Communication

Remotely Program Allen-Bradley Processors Over a Telemetry Network

Chapter 10

Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2

Setting up the System . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3

Configure the Processor . . . . . . . . . . . . . . . . . . . . . . . . 10-3

Configure the Modems for the PLC-5, SLC, and Logix

Processors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3

Configure the Modems for MicroLogix 1100/1200/1500

Controllers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4

Communicating Over the Telephone Line . . . . . . . . . . . . . 10-4

Initiate Modem Dialing. . . . . . . . . . . . . . . . . . . . . . . . . 10-5

Verify Connection to the Remote Modem . . . . . . . . . . . 10-6

Transfer Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-7

Disconnect the Telephone Link . . . . . . . . . . . . . . . . . . 10-7

Peer-to-Peer Communication . . . . . . . . . . . . . . . . . . . . . . . 10-8

Report-by-Exception and/or

Master Station-Initiated Communication . . . . . . . . . . . . . . . 10-9

Chapter 11

Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1

Remote Programming via RSLinx® Gateway™ . . . . . . . . . . 11-2

Remote Programming via SLC 5/05 Ethernet to

DF1 Passthru . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4

Remote Programming via Logix EtherNet/IP to DF1 Bridge. 11-7

Publication AG-UM008C-EN-P - February 2005

8 Table of Contents

Modem Cable Reference

Basic DF1 Protocol Troubleshooting

Appendix A

Appendix Objective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

Enhanced PLC-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2

1747-KE Interface Module . . . . . . . . . . . . . . . . . . . . . . . . . A-3

ASCII Terminal to 1747-KE module . . . . . . . . . . . . . . . . . . A-4

SLC 5/03, 5/04, or 5/05, Logix, and MicroLogix 1500

Channel 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5

1785-KE Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-6

MicroLogix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-7

Appendix B

Appendix Objectives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

General Tips. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

Communication Troubleshooting . . . . . . . . . . . . . . . . . . . . B-1

DF1 Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-3

DF1 Half-Duplex Protocol . . . . . . . . . . . . . . . . . . . . . . . . . B-4

DF1 Full-Duplex Protocol . . . . . . . . . . . . . . . . . . . . . . . . . B-6

DF1 Radio Modem Protocol. . . . . . . . . . . . . . . . . . . . . . . . B-7

Third-Party Supplier Contact Information

Worksheets

Appendix C

Appendix Objectives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1

Contact List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1

Appendix D

Appendix Objective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1

When You’re Finished. . . . . . . . . . . . . . . . . . . . . . . . . . . . D-2

How to Use the Worksheets . . . . . . . . . . . . . . . . . . . . . . . D-3

Worksheet 1.1 SCADA System Schematic . . . . . . . . . . . . . . D-4

Worksheet 2.1 Enhanced PLC-5 DF1 Half-Duplex Master

Station Configuration Using Standard Communication. . . . . D-5

Worksheet 2.2 Enhanced PLC-5 DF1 Half-Duplex Master Station Configuration Using Message-based Communication D-6 Worksheet 2.3 Enhanced PLC-5 DF1 Half-Duplex Slave

Station Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-7

Worksheet 2.4 Enhanced PLC-5 DF1 Full-Duplex

Point-to-Point Configuration . . . . . . . . . . . . . . . . . . . . . . . D-8

Worksheet 3.1 MicroLogix 1100/1200/1500 DF1 Half-Duplex Master Station Configuration Using Standard

Communication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-9

Worksheet 3.2 MicroLogix 1100/1200/1500 DF1 Half-Duplex Master Station Configuration Using Message-based

Communication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-10

Worksheet 3.3 MicroLogix 1100/1200/1500 DF1 Half-Duplex

Slave Station Configuration . . . . . . . . . . . . . . . . . . . . . . . D-11

Publication AG-UM008C-EN-P - February 2005

Table of Contents 9

Worksheet 3.4 MicroLogix 1100/1200/1500 DF1

Full-Duplex Point-to-Point Configuration . . . . . . . . . . . . . D-12

Worksheet 3.5 MicroLogix 1100/1200/1500 Radio Modem

Slave Station Configuration . . . . . . . . . . . . . . . . . . . . . . . D-13

Worksheet 4.1 SLC 5/03, 5/04, and 5/05 DF1 Half-Duplex Master Station Configuration Using Standard

Communication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-14

Worksheet 4.2 SLC 5/03, 5/04, and 5/05 DF1 Half-Duplex Master Station Configuration Using Message-based

Communication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-15

Worksheet 4.3 SLC 5/03, 5/04, and 5/05 DF1 Half-Duplex

Slave Station Configuration . . . . . . . . . . . . . . . . . . . . . . . D-16

Worksheet 4.4 SLC 5/03, 5/04, and 5/05 DF1 Full-Duplex

Point-to-Point Configuration . . . . . . . . . . . . . . . . . . . . . . D-17

Worksheet 4.5 SLC 5/03, 5/04, and 5/05 DF1 Radio

Modem Station Configuration . . . . . . . . . . . . . . . . . . . . . D-18

Worksheet 5.1 SLC 500 Processor with 1747-KE Module

DF1 Half-Duplex Slave Station Configuration . . . . . . . . . . D-19

Worksheet 5.2 SLC 500 Processor with 1747-KE Module

Point-to-Point Configuration . . . . . . . . . . . . . . . . . . . . . . D-20

Worksheet 6.1 MicroLogix 1000 DF1 Half-Duplex Slave

Station Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . D-21

Worksheet 7.1 Logix DF1 Half-Duplex Master Station

Configuration Using Standard Communication . . . . . . . . . D-22

Worksheet 7.2 Logix DF1 Half-Duplex Master Station

Configuration Using Message-based Communication . . . . D-23

Worksheet 7.3 Logix DF1 Half-Duplex Slave Station

Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-24

Worksheet 7.4 Logix DF1 Full-Duplex Point-to-Point

Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-25

Sample Ladder Logic

Appendix E

Appendix Objective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-1

SLC DF1 Half-Duplex Master Standard Mode,

Master-initiated MSG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-2

SLC DF1 Half-Duplex Master Message-based Mode and DF1

Radio Modem initiated MSG . . . . . . . . . . . . . . . . . . . . . . . E-4

SLC DF1 Half-Duplex Slave and DF1 Radio Modem

Report-by-Exception MSG . . . . . . . . . . . . . . . . . . . . . . . . . E-6

PLC-5 and MicroLogix 1100/1200/1500 DF1 Half-Duplex

Master Standard Mode, Master-initiated MSG . . . . . . . . . . . E-8

PLC-5 and MicroLogix 1100/1200/1500 DF1 Half-Duplex

Master Message-based, Master-initiated MSG . . . . . . . . . . E-10

PLC-5 and MicroLogix 1100/1200/1500 DF1 Half-Duplex

Slave Report-by-Exception MSG. . . . . . . . . . . . . . . . . . . . E-12

Publication AG-UM008C-EN-P - February 2005

10 Table of Contents

MicroLogix 1000 Analog DF1 Half-Duplex Slave

Report-by-Exception MSG . . . . . . . . . . . . . . . . . . . . . . . . E-14

Logix DF1 Half-Duplex Master Standard Mode,

Master-Initiated MSG . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-16

Logix DF1 Half-Duplex Master Message-based Mode,

Master-Initiated MSG . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-19

Logix DF1 Half-Duplex Slave Report-By-Exception MSG. . E-21

Glossary

Index

Publication AG-UM008C-EN-P - February 2005

Preface

What SCADA Information Is Available?

Audience

Two principle SCADA documents are available:

• SCADA System Application Guide Publication AG-UM008 (this

manual)

– Describes how to configure Allen-Bradley® products and

third-party modems

– Describes how to send messages – Provides application samples

• SCADA System Selection Guide (Publication AG-SG001)

– Presents Allen-Bradley capabilities for SCADA applications – Guides you through choosing SCADA system components

We designed this document for individuals who are configuring a SCADA system or are answering configuration questions. This document assumes you know how to:

• handle, install, and operate the products referenced in this

document

• install, navigate through, and use the software products

referenced in this document

• prepare cables, if necessary

1 Publication AG-UM008C-EN-P - February 2005

2 Preface

Contents of this Manual

Refer to the following listing for the contents of this user manual.

Chapter Title Contents

1 Designing

Communication

2 Configuring Enhanced

3 Configuring MicroLogix™

4 Configuring SLC™ 5/03,

5 Configuring SLC™ 500

6 Configuring MicroLogix

7 Configuring Logix

8 Configuring Modems Provides information on connecting

Processors

PLC-5

1100/1200/1500 Controllers

5/04, and 5/05 Processors

Processors with 1747-KE Interface Modules

1000 Controllers

Controllers

Design and configuration choices for getting information to and from slave stations.

Set up an enhanced PLC-5 processor as a master station, slave station, or a station on a point-to-point link.

Set up a MicroLogix 1100/1200/1500 controller as a master station, slave station, or a station on a point-to-point link.

Set up an SLC 5/03, 5/04, and 5/05 processor as a master station, slave station, or a station on a point-to-point link.

Set up an SLC 500 fixed or modular processor (SLC 5/01 or 5/02) with a 1747-KE as a remote station, or a station on a point-to-point link.

Set up a MicroLogix controller as a slave station, or a station on a point-to-point link.

Set up Logix controllers as a master station, slave station, or a station on a point-to-point link.

modems to Allen-Bradley devices.

10 Using Dial-up Telephone

11 Remotely Programming

A Modem Cable Reference Provides cable information. B Basic DF1 Protocol

C Third-Party Supplier

D Worksheets Provides worksheets to document your

E Sample Ladder Logic Provides information for developing your

Glossary

Configuring RSLinx® Classic Software for DF1 Half-Duplex Communications

Communication

Allen-Bradley Processors Over a Telemetry Network

Troubleshooting

Contact Information

Provides reference information needed while configuring RSLinx Classic communication server software as a DF1 half-duplex polling master station or as a DF1 half-duplex slave station.

Provides information on how to set up and initiate dial-up communication.

Provides information on how to set up and configure RSLogix programming terminals on Ethernet to program remote processors.

Provides information on how to troubleshoot communication errors.

Provides 3rd party vendor contact information.

serial channel configurations.

messaging logic.

Publication AG-UM008C-EN-P - February 2005

Preface 3

Terms

We use these terms frequently in this book:

Te rm Definition

Logix processor A collective name used to refer to ControlLogix™,

FlexLogix™, and CompactLogix™ processors.

Enhanced PLC-5 processor A collective name used to refer to PLC-5/11, -5/20,

-5/30, -5/40, -5/60, and PLC-5/80 processors.

Ethernet PLC-5 processor A collective name used to refer to PLC-5/20E,

-5/40E, and -5/80E processors.

master station A device (programmable controller with I/O modules

or a workstation) that sends data to and collects data from devices connected on a point-to-multipoint, half-duplex network.

slave station A device (programmable controller with I/O modules)

that is located in a remote site away from the master station and that controls I/O points at the remote site. A slave station accepts commands from and can send data (if capable) to a master station via a telemetry network.

See the Glossary for other definitions.

Address Conventions

Addresses

These values Are represented as

octal X decimal X

Publication AG-UM008C-EN-P - February 2005

4 Preface

Related Publications

The following documents contain additional information concerning Allen-Bradley programmable controller products. To obtain a copy, contact your local Allen-Bradley office or distributor:

Title Publication Number

Enhanced and Ethernet PLC-5 Programmable Controllers User Manual

PLC-5 Instruction Set Reference Manual 1785-RM001 SLC 500 Instruction Set Reference Manual 1747-RM001 SLC 500 Modular Hardware Style Manual 1747-UM0011 DH-485/RS232C Interface Module User Manual 1747-UM005 MicroLogix 1000 Programmable Controllers Users Manual 1761-UM003 ControlLogix System User Manual 1756-UM001 Logix5000™ Controllers Common Procedures Programming

Manual Logix Controllers General Instruction Set Reference

Manual MicroLogix 1200 and 1500 Instruction Set Reference

Manual MicroLogix 1200 User Manual 1762-UM001

1785-UM012

1756-PM001

1756-RM003

1762-RM001

MicroLogix 1500 User Manual 1764-UM001 CompactLogix System User Manual 1769-UM011 FlexLogix System User Manual 1794-UM001 DF1 Protocol and Command Set Reference Manual 1770-RM516 2004-2005 Americas Edition/Encompass Program Product

Designing Communication

Chapter

Chapter Objectives

Use this chapter along with the configuration chapters of the devices in your SCADA system to help you make design and configuration choices for getting information to and from slave stations.

While designing your communication scheme, consider these application requirements:

• responsiveness

• determinism

• cost

• efficiency

The factors that affect communication are a result of the protocol you are use, either half-duplex or full-duplex.

For information about See page

choosing a polling mode for the DF1 Half-Duplex protocol 1-2 designing a communication scheme using

standard-communication mode designing a communication scheme using message-based

communication mode

1-8

1-15

designing communication for DF1 Full-Duplex protocol 1-16 designing communication for DF1 Radio Modem protocol 1-17 what to do next 1-19

1 Publication AG-UM008C-EN-P - February 2005

1-2 Designing Communication

Choosing a Polling Mode for DF1 Half-Duplex Master

A master station can be configured to communicate with slave stations in either Message-based polling mode or Standard polling mode. The pros and cons of each polling mode are described below.

Message-Based Polling Mode

Message-based polling mode is best used in networks when communication with the slave stations is not time critical and where the user needs to be able to limit when and how often the master station communicates with each slave station. It is NOT recommended for systems that require time continuous communication between the master and all the slave stations have MSG instructions in their programs.

With Message-Based polling mode, the only time a master station communicates with a slave station is when a message (MSG) instruction in ladder logic is triggered to that particular slave station’s address. This polling mode gives the user complete control (through ladder logic) over when and how often to communicate with each slave station.

If multiple MSG instructions are triggered simultaneously, they will be executed in order, one at a time, to completion (i.e., the first MSG queued up will be transmitted and completed to done or error before the next queued up MSG is transmitted. Refer to appendix E for sample application programs). Any time a message is triggered to a slave station that can’t respond (for instance, if its modem fails), the message will go through retries and timeouts that will slow down the execution of all the other queued up messages. The minimum time to message to every responding slave station increases linearly with the number of slave stations that can’t respond.

If the Message-based selection is ‘don’t allow slaves to initiate messages,’ then even if a slave station triggers and queues up a MSG instruction in its ladder logic, the master station will not process it. This mode is similar to how a master/slave network based on Modbus protocol would work, since Modbus slave stations cannot ever initiate a message.

If the Message-based selection is ‘allow slaves to initiate messages,’ when a slave station initiates a message to the master station (polled report by exception messaging) or to another slave station (slave-to-slave messaging), the MSG command packet will remain in that slave station’s transmit queue until the master station triggers its own MSG command packet to it (which could be seconds, minutes or hours later, depending on the master’s ladder logic).

Publication AG-UM008C-EN-P - February 2005

Designing Communication 1-3

Standard Polling Mode

Standard polling mode is strongly recommended for larger systems that require time critical communication between the master and all the slave stations, or for any system where slave station-initiated messages are going to be used (this includes slave programming over the network, since this uses the same mechanism that slave-to-slave messaging uses). The Active Node Table automatically keeps track of which slaves are (and are not) communicating. Standard polling mode should NOT be used in cases where the user needs to be able to limit when and how often the master station communicates with each slave station.

Standard polling mode causes the master station to continuously send one or more 4-byte poll packets to each slave station address configured by the user in the poll list(s) in round robin fashion. As soon as the end of the polling list is reached, the master station immediately goes back and starts polling slave stations from the top of the polling list over again. This is independent and asynchronous to any MSG instructions that might be triggered in the master station ladder logic. In fact, this polling continues even while the master station is in program mode. Refer to chapter 3 of the DF1 Protocol and Command Set Reference Manual, publication 1770-RM516, for additional information.

When a MSG instruction is triggered while the master station is in run mode, the master station will transmit the message packet just after it finishes polling the current slave station in the poll list and before it starts polling the next slave station in the poll list (no matter where in the poll list it is currently at). If multiple MSG instructions have been triggered simultaneously, at least four message packets may be sent out between two slave station polls. Each of these messages will have an opportunity to complete when the master polls the slave station that was addressed in the message packet as it comes to it in the poll list.

If each of the transmitted message packets is addressed to a different slave station, the order of completion will be based upon which slave station address comes up next in the poll list, not the order that the MSG instructions were executed and transmitted in.

When a slave station receives a poll packet from the master station, if it has one or more message packets queued up to transmit (either replies to a command received earlier or MSG commands triggered locally in ladder logic), the slave station will transmit the first message packet in the transmit queue.

If the standard mode selection is ‘single message per poll scan,’ then the master station will then go to the next station in the poll list. If the standard mode selection is ‘multiple messages per poll scan,’ the

Publication AG-UM008C-EN-P - February 2005

1-4 Designing Communication

master station will continue to poll this slave station until its transmit queue is empty.

The master station knows the slave station has no message packets queued up to transmit when the slave station responds to the master poll packet with a 2-byte poll response.

Every time a slave station responds or doesn’t respond to its poll packet, the master station automatically updates its active node list (again, even if it’s in program mode). In this list, one bit is assigned to each possible slave station address (0 to 254). If a slave station doesn’t respond when it is polled, its active node list bit is cleared. If it does respond when it is polled, its active node bit is set. Besides being an excellent online troubleshooting tool, two common uses of the active node list are to report good/bad communication status for all slave stations to an operator interface connected to the master station for monitoring, alarming and logging purposes, and to precondition MSG instructions to each particular slave.

This second use is based on the supposition that if a slave station didn’t respond the last time it was polled (which was just a few seconds ago, if that long), then chances are it won’t be able to receive and respond to a MSG instruction now, and so it would most likely just end up going through the maximum number of retries and timeouts before completing in error (which slows down both the poll scan and any other messaging going on). Using this technique, the minimum time to message to every responding slave station actually decreases as the number of slave stations that can’t respond increases.

IMPORTANT

In order to remotely monitor and program the slave stations over the half-duplex network while the master station is configured for Standard polling mode, the programming computer DF1 slave driver (Rockwell Software RSLinx) station address must be included in the master station poll list.

About Polled Report-by-Exception

Publication AG-UM008C-EN-P - February 2005

Polled report-by-exception lets a slave station initiate data transfer to its master station, freeing the master station from having to constantly read blocks of data from each slave station to determine if any slave input or data changes have occurred. Instead, through user programming, the slave station monitors its own inputs for a change of state or data, which triggers a block of data to be written to the master station when the master station polls the slave.

Designing Communication 1-5

If your SCADA application is time-critical and any two or more of the following apply, then you can benefit from polled report-by-exception messaging:

• communication channel is slow (2400 bps or less)

• average number of words of data to monitor in each slave

station is greater than five

• number of slave stations is greater than ten

About Slave-to-Slave Messaging

Most SCADA half-duplex protocols do not allow one slave station to talk to another slave station, except through special application-specific code, which requires processing overhead in the master station. However, Allen-Bradley’s DF1 half-duplex protocol implements slave-to-slave communications as a feature of the protocol within the master station, without any additional application code or extra processing overhead. Refer to chapter 3 of the DF1 Protocol and Command Set Reference Manual, publication 1770-RM516, for additional information.

If one slave station has a message to send to another, it simply includes the destination slave station’s address in the message instruction’s destination field in place of the master station’s address when responding to a poll. The master station checks the destination station address in every packet header it receives from any slave station. If the address does not match its own station address, the entire message is forwarded back onto the telemetry network to the appropriate slave station, without any further processing.

IMPORTANT

Slave stations using 1747-KE interfaces can respond to slave-to-slave messages but cannot initiate slave-to-slave messages.

Publication AG-UM008C-EN-P - February 2005

1-6 Designing Communication

Addressing Tips

Each station on the network including the master station must have a unique address. The address range is 0 to 254

have a maximum of 254 address 255

(3778) is the broadcast address, which you cannot select

stations on a single telemetry network. Station

as a station’s individual address.

A remote programming terminal station address should be reserved, even if remote programming is not considered a requirement initially. This address will need to be periodically polled, even though it will remain on the inactive poll list unless a remote programming terminal is online.

SLC 500 and MicroLogix 1000 Processor Addressing Considerations

When an SLC 5/02 or MicroLogix 1000 slave station issues a

PLC

-2-type message to a PLC-5 master station, the message’s destination in the PLC-5 processor’s data table is an integer file with the file number equal to the SLC 500 or MicroLogix 1000 processor station address.

(3768), so you can

An address lower than 9 may interfere with a PLC-5 processor master station since files 0-8 are usually left in their default configuration; file 9 is often used by programmers for the I/O list. Station address 255

is the broadcast address. So, assign addresses between 10

TIP

For all other master station types, the SLC 5/02 or MicroLogix 1000 slave station can initiate a 500

-25410.

CPU-type message.

When using an SLC 5/03, 5/04, or 5/05 processor, or a MicroLogix 1100, 1200 or 1500 controller, as a master station, the poll list configuration consists of a contiguous block of addresses. Therefore, assign slave station addresses in a contiguous block in order to avoid polling for nonexistent slave stations.

Publication AG-UM008C-EN-P - February 2005

Designing Communication 1-7

SLC 500 Processors with a 1747-KE Module Addressing Considerations

Since you can have up to 254 devices on a half-duplex network and 32 devices on a DH-485 network, to allow 255 DH-485 nodes requires using a group number. This parameter defines the address group of the SLC 500 half-duplex address. Each address group can consist of 32 addresses.

The slave address of the SLC 500 processor is determined with the following formula: (32*G)+ Α, where G is the group number (0 to 7) and A is the DH-485 node address of the SLC 500 processor.

One station address within each group of size 32 must be reserved for any 1747-KE modules configured with that group number. A second address within each group should also be reserved for local DH-485 programming terminals. These 16 addresses (two per group) should never have to be polled by the master station.

ATTENTION

Do not use slave addresses contained within a KE group. When nodes are added to respective DH-485 networks, there is a possibility of duplicate nodes.

Publication AG-UM008C-EN-P - February 2005

1-8 Designing Communication

Communication Scheme Design Using Standard-Mode

Polling List

Stn 1 Stn 2

Stn 3

1. Master station polls a slave station for data.

2. If the slave station has data to send, then it sends a

data packet. If there is no data to send then it sends an end of transmission packet (DLE EOT).

Standard-communication mode for an Allen-Bradley master station uses centralized polling to gather data from slave stations. A master station using this communication technique asks (polls) individual slave stations if they have any information to send. All stations on the link ‘hear’ the master station’s requests, but only the slave station to which a request is addressed replies. PLC-5, Logix and RSLinx master stations poll slave stations based on an ordered list (polling list) configured by the system designer. SLC 500 and MicroLogix master stations poll slave stations sequentially in a range of addresses configured by the system designer.

Figure 1.1 shows how a slave

station gets polled and how it responds.

A master station polls the slave stations in the order the slave stations appear on the list. Slave stations send either a data packet or a packet indicating that the station has no data to send.

Figure 1.1 Slave Station Polling and Response

Master Station

Modem

Return Data Packet or DLE EOT to Master

Modem

slave station 1

Poll to slave

Modem

slave station 2

Modem

slave station 3

Polling List

Stn 1 Stn 2

Master Station

Stn 3

1. Master station polls the next slave station for data.

2. If the slave station has data to send, then it sends a

data packet. If there is no data to send then it sends an end of transmission packet (DLE EOT).

3. Master station continues to poll each slave station

in the polling list. When the end of the list is reached, the master station then moves back to the beginning of the list and starts the polling sequence over again.

Publication AG-UM008C-EN-P - February 2005

Modem

Return Data Packet or DLE EOT to Master

Modem

slave station 1

Modem

slave station 2

Poll to slave

Modem

slave station 3

41180

Designing Communication 1-9

When the master station is configured for standard-communication mode, you do not need to program any master-station message instructions to communicate with slave stations. Communication with slave stations occurs by the master station sending polling packets to slave stations. You only need message instructions when you want the master station to write data to or read data from a location within a slave station’s data table.

To help you understand See

standard-communication mode Figure 1.2 how a master station requests data Figure 1.3

Figure 1.2 Standard Communication Mode

• Check for and send

outgoing MSG

• Select next station

to poll

timeout received and station active and tries < or = ‘DF1 message retries’

MSG received and multiple mode

forward data to or return data from data table

timeout received and station inactive

• Send poll

• Start ACK timeout

• Wait for EOT or

MSG (or timeout)

timeout received and station active and tries > ‘DF1 message retries’ make

station inactive

EOT received indicating no MSG to send make station active

(if inactive)

MSG received and single poll mode forward data

to or return data from data table

41181

Publication AG-UM008C-EN-P - February 2005

1-10 Designing Communication

Master data table

reply packet received return

data

Figure 1.3 How a Master Station Requests Data

• Ladder logic

triggers MSG

• Master driver

formats command packet

ACK timeout received and tries > ‘DF1 message retries’ return error

indication

• Send command

packet

• Start ACK timer

• Wait for ACK (or

timeout)

ACK timeout received and station active and tries < or = ‘DF1 message retries’

reply timeout received

return error indication

• Start reply timer

• Resume polling

• Wait for reply (or

timeout)

ACK received

To design a communication scheme using standard-communication mode, you must do the following:

• design a polling scheme

• plan for timing issues

41182

Publication AG-UM008C-EN-P - February 2005

Designing Communication 1-11

Designing a Polling Scheme

Each master station in a SCADA application must have a polling scheme configured. To design a polling scheme, do the following:

• choose the type of scheme best suited for your application

• optimize your polling scheme to obtain the best efficiency

The master station you are using determines the type of polling choices you have; however, Allen-Bradley master stations offer similar choices, such as:

• normal and priority polling lists

• ability to poll a slave station:

– once per occurrence in the poll list (single) – until it has no more messages to send (multiple)

Choosing Normal or Priority Polling Lists

Slave stations listed in a priority poll list are polled more frequently than those listed in the normal poll list. Place the slave stations that you need information from more frequently in a priority poll list.

Within each poll list, slave stations are assigned a status, which is either active or inactive. A slave station becomes inactive when it does not respond to a master station’s poll packet after the configured number of retries.

If your master station is a Logix controller or PLC-5, you can use application logic to reorder the polling lists and priority while the application logic is executing.

Figure 1.4 and Figure 1.5 show how normal and priority lists relate to one another.

Publication AG-UM008C-EN-P - February 2005

1-12 Designing Communication

Figure 1.4 The master station scans slave stations in a set sequence.

1. Scans all stations in the active priority

2. Scans one station in the inactive priority

3. Scans stations in the active normal poll file

4. Scans one station in the inactive normal poll file

Active Priority

Inactive Priority

Active Normal

poll file.

based on the normal poll group size, which you specify during configuration. For example, if the group size were 3, then three stations would be polled in the normal file before the master continues to the next step in the sequence.

after all stations in the active normal list have been polled.

Figure 1.5 Here is how the polling sequence applies to an application.

Poll List STN1 STN7

Poll List STN2 STN6

Poll List STN3 STN4

Group size = 1

Active Priority Poll List

Master

Station

Inactive Priority Poll List

Active Normal Poll List

aa bb

Modem

Inactive Normal Poll List

41183

Polling Sequence: STN1 STN7 STN2 STN3

STN1 STN7 STN6 STN4 STN5

Inactive Normal

Beginning of new scan

Poll List

STN5

Modem

41184

Publication AG-UM008C-EN-P - February 2005

+ 390 hidden pages