Allen-Bradley 1756-IA16I, 1756-IB16, 1756-IB16IF, 1756-IB16I, 1756-IA32 User Manual

...

ControlLogix Digital I/O Modules

Catalog Numbers 1756-IA8D, 1756-IA16, 1756-IA16I, 1756-IA32, 1756-IB16, 1756-IB16D, 1756-IB16I, 1756-IB16IF, 1756-IB32, 1756-IC16, 1756-IG16, 1756-IH16I, 1756-IM16I, 1756-IN16, 1756-IV16, 1756-IV32, 1756-OA8, 1756-OA8D, 1756-OA8E, 1756-OA16, 1756-OA16I, 1756-OB8, 1756-OB8EI, 1756-OB8I, 1756-OB16D, 1756-OB16E, 1756-OB16I, 1756-OB16IEF, 1756-OB16IEFS, 1756-OB16IS, 1756-OB32, 1756-OC8, 1756-OG16, 1756-OH8I, 1756-ON8, 1756-OV16E, 1756-OV32E, 1756-OW16I, 1756-OX81

User Manual

Important User Information

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

available from

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

) describes some important differences between solid-state equipment and hard-wired electromechanical devices. Because of this difference, and also because of the wide variety of uses for solid-state equipment, all persons responsible for applying this equipment must satisfy themselves that each intended application of this equipment is acceptable.

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

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

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

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

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

Allen-Bradley, ControlLogix, ControlLogix-XT, DH+, Data Highway Plus, Integrated Architecture, Rockwell Software, Rockwell Automation, RS Logix, RSNetWorx, and TechConnect are trademarks of Rockwe ll Automation, Inc.

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

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

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

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

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

IMPORTANT

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

Rockwell Automation Publication 1756-UM058G-EN-P - November 2012 3

Summary of Changes

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

Top ic Pag e

Studio 5000™ Logix Designer application is the rebranding of RSLogix™ 5000 software 11

Added the 1756-OB16IEFS module to the list of I/O modules 15

Added content to describe when output data is sent to the 1756-OB16IEFS module in motion applications

Added the 1756-OB16IEFS module to the CIP Sync time section 48

Added the 1756-OB16IEFS module to sections about electronic fusing, diagnostic latching, and time-scheduled output control

54, 58, 63

Added the 1756-OB16IEFS module to the list of fast I/O modules 83

Added software version requirements for the 1756-OB16IEFS module 84

Added the 1756-OB16IEFS module to the table of connection formats 133

Added the wiring diagram for the 1756-OB16IEFS module 165

Added status indicators for the 1756-OB16IEFS module 179

Added tag definitions for the 1756-OB16IEFS module 202

Added the 1756-OB16IEFS module to the list of IFMs 245

4 Rockwell Automation Publication 1756-UM058G-EN-P - November 2012

Summary of Changes

Notes:

Rockwell Automation Publication 1756-UM058G-EN-P - November 2012 5

Table of Contents

Preface

Studio 5000 Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Additional Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Chapter 1 What Are ControlLogix Digital I/O Modules?

Available Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

I/O Modules in the ControlLogix System . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Module Identification and Status Information. . . . . . . . . . . . . . . . . . . . . . 17

Chapter 2 Digital I/O Operation in the ControlLogix System

Ownership . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Use RSNetWorx and RSLogix 5000 Software . . . . . . . . . . . . . . . . . . . . . . 20

Internal Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Input Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Output Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Direct Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Rack-optimized Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Suggestions for Rack-optimized Connections . . . . . . . . . . . . . . . . . . . 26

Input Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Input Modules in a Local Chassis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

RPI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

COS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Trigger Event Tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Input Modules in a Remote Chassis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Remote Input Modules Connected via the ControlNet Network. 29

Remote Input Modules Connected via the EtherNet/IP Network 30

Output Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Output Modules in a Local Chassis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Output Modules in a Remote Chassis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Remote Output Modules Connected via the ControlNet Network. 32

Remote Output Modules Connected via the EtherNet/IP Network 33

Listen-only Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Multiple Owner-Controllers of Input Modules . . . . . . . . . . . . . . . . . . . . . 34

Configuration Changes in an Input Module with Multiple Owners . . 35

Chapter 3

Common Module Features

Input Module Compatibility. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Output Module Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Common Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Removal and Insertion Under Power. . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Module Fault Reporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Software Configurable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Electronic Keying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Module Inhibiting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

6 Rockwell Automation Publication 1756-UM058G-EN-P - November 2012

Table of Contents

Use the System Clock to Timestamp Inputs and Schedule Outputs. 47

Producer/Consumer Communication. . . . . . . . . . . . . . . . . . . . . . . . . . 50

Status Indicator Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Common Features Specific to Input Modules. . . . . . . . . . . . . . . . . . . . . . . 50

Data Transfer on Either Cyclic Time or Change of State . . . . . . . . . 51

Set RPI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Enable Change of State. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Software Configurable Filter Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Isolated and Nonisolated Varieties of Input Modules . . . . . . . . . . . . 53

Multiple Input Point Densities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Common Features Specific to Output Modules . . . . . . . . . . . . . . . . . . . . . 54

Configurable Point-level Output States. . . . . . . . . . . . . . . . . . . . . . . . . 55

Output Data Echo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Isolated and Nonisolated Varieties of Output Modules . . . . . . . . . . 56

Multiple Output Point Densities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Electronic Fusing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Field Power Loss Detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Diagnostic Latch of Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Time-scheduled Output Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Fault and Status Reporting between Input Modules and Controllers. . 64 Fault and Status Reporting between Output Modules and Controllers 65

Chapter 4

Diagnostic Module Features

Diagnostic Input Module Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Diagnostic Output Module Compatibility. . . . . . . . . . . . . . . . . . . . . . . . . . 68

Diagnostic Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Diagnostic Latch of Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Diagnostic Timestamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

8-Point AC/16-Point DC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Point-level Fault Reporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Features Specific to Diagnostic Input Modules. . . . . . . . . . . . . . . . . . . . . . 71

Diagnostic Change of State for Input Modules . . . . . . . . . . . . . . . . . . 71

Open Wire Detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Field Power Loss Detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Features Specific to Diagnostic Output Modules . . . . . . . . . . . . . . . . . . . . 75

Field Wiring Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

No Load Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Field-side Output Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

Pulse Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

Diagnostic Change of State for Output Modules . . . . . . . . . . . . . . . . 79

Fault and Status Reporting between Input Modules and Controllers. . 79 Fault and Status Reporting between Output Modules and Controllers 81

Rockwell Automation Publication 1756-UM058G-EN-P - November 2012 7

Table of Contents

Chapter 5

Fast Module Features

Fast Input Module Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Fast Output Module Compatibility. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

Fast Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

Response Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Features Specific to Fast Input Modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Pulse Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

Per Point Timestamping and Change of State. . . . . . . . . . . . . . . . . . . 87

Software Configurable Filter Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Dedicated Connection for Event Tasks. . . . . . . . . . . . . . . . . . . . . . . . . 93

Features Specific to Fast Output Modules . . . . . . . . . . . . . . . . . . . . . . . . . . 95

Programmable Fault State Delays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

Pulse Width Modulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Fault and Status Reporting between Input Modules and Controllers 106 Fault and Status Reporting between Output Modules and Controllers 107

Chapter 6

Install ControlLogix I/O Modules

Install the Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Key the Removable Terminal Block. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

Connect the Wires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

RTB Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

RTB Wiring Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

Assemble the Removable Terminal Block and Housing. . . . . . . . . . . . . 119

Choose Extended-depth Housing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

Cabinet Size Considerations with Extended-depth Housing . . . . 121

Install the Removable Terminal Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

Remove the Removable Terminal Block. . . . . . . . . . . . . . . . . . . . . . . . . . . 123

Remove the Module from the Chassis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

Chapter 7

Configure ControlLogix Digital I/O Modules

Configuration Process Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128

Create a New Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

Communication or Connection Formats. . . . . . . . . . . . . . . . . . . . . . 131

Edit the Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

Connection Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

View and Change Module Tags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

Chapter 8

Wiring Diagrams

1756-IA8D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

1756-IA16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

1756-IA16I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

1756-IA32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

1756-IB16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142

1756-IB16D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

1756-IB16I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

1756-IB16IF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

8 Rockwell Automation Publication 1756-UM058G-EN-P - November 2012

Table of Contents

1756-IB32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

1756-IC16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

1756-IG16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

1756-IH16I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149

1756-IM16I. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150

1756-IN16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150

1756-IV16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151

1756-IV32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152

1756-OA8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153

1756-OA8D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154

1756-OA8E. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155

1756-OA16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156

1756-OA16I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

1756-OB8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158

1756-OB8EI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

1756-OB8I. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

1756-OB16D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161

1756-OB16E. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

1756-OB16I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163

1756-OB16IEF. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164

1756-OB16IEFS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165

1756-OB16IS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166

1756-OB32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

1756-OC8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168

1756-OG16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169

1756-OH8I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170

1756-ON8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171

1756-OV16E. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

1756-OV32E. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173

1756-OW16I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174

1756-OX8I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175

Appendix A

Troubleshoot Your Module

Status Indicators for Input Modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

Status Indicators for Output Modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

Use RSLogix 5000 Software for Troubleshooting . . . . . . . . . . . . . . . . . . 180

Fault Type Determination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181

Appendix B

Tag Definitions

Standard and Diagnostic Input Module Tags . . . . . . . . . . . . . . . . . . . . . . 183

Standard and Diagnostic Output Module Tags . . . . . . . . . . . . . . . . . . . . 186

Fast Input Module Tags. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

Fast Output Module Tags. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194

1756-OB16IEF Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194

1756-OB16IEFS Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202

Array Data Structures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211

Rockwell Automation Publication 1756-UM058G-EN-P - November 2012 9

Table of Contents

Appendix C

Use Ladder Logic To Perform Run Time Services and Reconfiguration

Using Message Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213

Processing Real-time Control and Module Services . . . . . . . . . . . . . . . . 214

One Service Performed Per Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . 214

Create a New Tag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214

Enter Message Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217

Configuration Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218

Communication Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221

Use Timestamped Inputs and Scheduled Outputs

for Standard and Diagnostic I/O Modules. . . . . . . . . . . . . . . . . . . . . 222

Use Timestamped Inputs and Scheduled Outputs

for Fast I/O Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224

Reset a Fuse, Perform Pulse Test and Reset Latched Diagnostics. 227

Perform a WHO to Retrieve Module Identification and Status. . 228

Review of Tags in Ladder Logic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231

Appendix D

Choose a Correct Power Supply

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .233

Appendix E

Motor Starters for Digital I/O Modules

Determine the Maximum Number of Motor Starters. . . . . . . . . . . 236

Appendix F

Major Revision Upgrades

If Using a Compatible or Disabled Keying I/O Configuration . . . . . . 238

If Using an Exact Match Keying Configuration . . . . . . . . . . . . . . . . . . . . 238

Appendix G

1492 IFMs for Digital I/O Modules

Cable Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239

Appendix H

History of Changes

1756-UM058F-EN-P, April 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249

1756-UM058E-EN-P, August 2010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250

Glossary

Index

10 Rockwell Automation Publication 1756-UM058G-EN-P - November 2012

Table of Contents

Notes:

Rockwell Automation Publication 1756-UM058G-EN-P - November 2012 11

Preface

This manual describes how to install, configure, and troubleshoot your ControlLogix® digital I/O modules. There is also a complete listing of digital input and output modules, including specifications and wiring diagrams. You must be able to program and operate a ControlLogix controller to efficiently use your digital I/O module.

Studio 5000 Environment

The Studio 5000™ Engineering and Design Environment combines engineering and design elements into a common environment. The first element in the Studio 5000 environment is the Logix Designer application. The Logix Designer application is the rebranding of RSLogix™ 5000 software and will continue to be the product to program Logix5000™ controllers for discrete, process, batch, motion, safety, and drive-based solutions.

The Studio 5000 environment is the foundation for the future of Rockwell Automation® engineering design tools and capabilities. It is the one place for design engineers to develop all the elements of their control system.

12 Rockwell Automation Publication 1756-UM058G-EN-P - November 2012

Preface

Additional Resources

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

You can view or download publications at

http://www.rockwellautomation.com/literature/

. To order paper copies of technical documentation, contact your local Allen-Bradley distributor or Rockwell Automation sales representative.

Resource Description

1756 ControlLogix I/O Modules Specifications Technical Data, publication 1756-TD002

Provides specifications for ControlLogix I/O modules.

ControlLogix High-speed Counter Module User Manual, publication 1756-UM007

Describes how to install, configure, and troubleshoot the 1756-HSC counter module.

ControlLogix Low-speed Counter Module User Manual, publication 1756-UM536

Describes how to install, configure, and troubleshoot the 1756-LSC8XIB8I counter module.

ControlLo gix Peer I/O Control Appl ication Techni que, publication 1756-AT016

Describes typical peer control applications and provides details about how to configure I/O modules for peer control operation.

Position-based Output Control with the MAOC Instruction, publication 1756-AT017

Describes typical applications for using scheduled output modules with the Motion Axis Output Cam (MAOC) instruction.

Integrated Architecture and CIP Sync Configuration Application Technique, publication IA-AT003

Describes how to configure CIP Sync with Integrated Architecture™ products and applications.

ControlLogix Chassis and Power Supplies Installation Instructions, publication 1756-IN005

Describes how to install and troubleshoot standard and ControlLogix-XT versions of the 1756 chassis and power supplies, including redundant power supplies.

ControlLogix Analog I/O Modules User Manual, publication 1756-UM009

Describes how to install, configure, and troubleshoot ControlLogix analog I/O modules.

ControlLogix Data Highway Plus-Remote I/O Communication Interface Module User Manual, publication 1756-UM514

Describes how to configure and operate the ControlLogix DH+™ / Remote I/O module.

ControlLogix-XT Data Highway Plus-Remote I/O Communication Interface Module Installation Instructions, publication 1756-IN638

Describes how to install, configure, and troubleshoot the ControlLogix-XT Data Highway Plus™-Remote I/O Communication Interface module.

ControlLogix System User Manual, publication 1756 UM001

Describes how to install, configure, program, and operate a ControlLogix system.

Industrial Automation Wiring and Grounding Guidelines, publication 1770-4.1

Provides general guidelines for installing a Rockwell Automation industrial system.

Product Certifications website, http://ab.com

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

Rockwell Automation Publication 1756-UM058G-EN-P - November 2012 13

Chapter 1

What Are ControlLogix Digital I/O Modules?

ControlLogix® digital I/O modules are input and output modules that provide On/Off detection and actuation. By using the producer/consumer network model, digital I/O modules can produce information when needed while providing additional system functions.

Available Features

The table lists several features available on ControlLogix digital I/O modules.

Top ic Pag e

Available Features 13

I/O Modules in the ControlLogix System 14

Module Identification and Status Info rmation 17

Feature Description

Removal and Insertion Under Power (RIUP) You can remove and insert modules and removable terminal blocks

(RTB) while power is applied.

Producer/consumer communication This communication method is an intelligent data exchange between

modules and other system devices in which each module produces data without first being polled.

System time stamp of data A 64-bit system clock places a time stamp on the transfer of data

between the module and its owner-controller.

Module-level fault reporting and field-side diagnostic detection

Fault and diagnostic detection capabilities to help you effec tively and efficiently use your module and troubleshoot your application.

Agency Certification Class 1, Division 2 agency certification for any applic ation that

requires approval.

14 Rockwell Automation Publication 1756-UM058G-EN-P - November 2012

Chapter 1 What Are ControlLogix Digital I/O Modules?

I/O Modules in the ControlLogix System

ControlLogix modules mount in a ControlLogix chassis and require either a removable terminal block (RTB) or a Bulletin 1492 wiring interface module

(IFM)

(1)

to connect all field-side wiring.

Before you install and use your module, you must do the following:

• Install and ground a 1756 chassis and power supply. To install these products, refer to the publications listed in Additional Resources

page 12.

• Order and receive an RTB or IFM and its components for your application.

(1) The ControlLogix system has been agency certified using only the ControlLogix RTB catalog numbers 1756-TBCH, 1756-T BNH,

1756-TBSH, and 1756-TBS6H. Any application that requires agency certification of the ControlLogix system using other wiring termination methods may require application-specific approval by the certifying agenc y.

IMPORTANT

RTBs and IFMs are not included with your module purchase. See page 116 for RTBs and page 239

for IFMs.

Table 1 - ControlLogix Digital I/O Modules

Cat. No. Description Page

1756-IA8D 79…132V AC 8-point diagnostic input module 139

1756-IA16 74…132V AC 16-point input module 139

1756-IA16I 79…132V AC 16-point isolated input module 140

1756-IA32 74…132V AC 32-point input module 141

1756-IB16 10…31.2V DC 16-point input module 142

1756-IB16D 10…30V DC diagnostic input module 143

1756-IB16I 10…30V DC 16-point, isolated input module 144

1756-IB16IF 10…30V DC,16-point, isolated, fast peer control input module 145

1756-IB32 10…31.2V DC 32-point input module 146

1756-IC16 30…60V DC 16-point input module 147

1756-IG16 Transitor-transitor logic (TTL) input module 148

1756-IH16I 90…146V DC 16-point isolated input module 149

1756-IM16I 159…265V AC 16-point isolated input module 150

1756-IN16 10…30V AC 16-point input module 150

1756-IV16 10…30V DC 16-point sourcing current input module 151

1756-IV32 10…30V DC 32-point sourcing current input module 152

1756-OA8 74…265V AC 8-point output module

153

1756-OA8D 74…132V AC 8-point diagnostic output module 154

1756-OA8E 74…132V AC 8-point electronically-fused output module 155

1756-OA16 74... 265V AC 16-point output module 156

1756-OA16I 74…265V AC 16-point isolated output module 157

1756-OB8 10…30V DC 8-point output module 158

1756-OB8EI 10…30V DC 8-point electronically-fused, isolated output module 159

1756-OB8I 10…30V DC 8-point isolated output module 160

1756-OB16D 19.2…30V DC 16-point diagnostic output module 161

Rockwell Automation Publication 1756-UM058G-EN-P - November 2012 15

What Are ControlLogix Digital I/O Modules? Chapter 1

1756-OB16E 10…31.2V DC 16-point electronically-fused output module 162

1756-OB16I 10…30V DC 16-point isolated output module 163

1756-OB16IEF 10…30V DC,16-point, isolated, fast peer control output module 164

1756-OB16IEFS 10…30V DC, 16-point, isolated, fast, scheduled per point output module 165

1756-OB16IS 10…30V DC scheduled, isolated output module 166

1756-OB32 10…31.2V DC 32-point output module 167

1756-OC8 30…60V DC 8-point output module 168

1756-OG16 Transitor-transitor logic (TTL) output module 169

1756-OH81 90…146V DC 8-point isolated output module 170

1756-ON8 10…30V AC 8-point output module 171

1756-OV16E 10…30V DC 16-point electronically-fused, sinking current output module 172

1756-OV32E 10…30V DC 32-point electronically-fused, sinking current output module 173

1756-OW16I 10…265V, 5-150V DC 16-point isolated contact module 174

1756-OX8I 10…265V, 5-150V DC 8-point isolated contact module 175

Table 1 - ControlLogix Digital I/O Modules (continued)

Cat. No. Description Page

16 Rockwell Automation Publication 1756-UM058G-EN-P - November 2012

Chapter 1 What Are ControlLogix Digital I/O Modules?

Figure 1 - Parts Illustration

40200-M

DC OUTPUT

01234567

Removable Terminal Block

Item Description

1 Backplane Connector—Interface for the ControlLogix system that connects the module to the

backplane.

2 Top and bottom guides—Guides provide assistance in seating the RTB or IFM onto the module.

3 Status indicators—Indicators display the status of communication, module health, and input/output

devices. Indicators help in troubleshooting anomalies.

4 Connector pins—Input/output, power, and grounding connections are made to the module through

these pins with the use of an RTB or IFM.

5 Locking tab—The locking tab anchors the RTB or IFM on the module, maintaining wiring connections.

6 Slots for keying—Mechanically keys the RTB to prevent making the wrong wire connections to your

module.

Rockwell Automation Publication 1756-UM058G-EN-P - November 2012 17

What Are ControlLogix Digital I/O Modules? Chapter 1

Module Identification and Status Information

Each ControlLogix I/O module maintains specific identification information that separates it from all other modules. This information assists you in tracking all the components of your system.

For example, you can track module identification information to know which modules are located in any ControlLogix chassis at any time. While retrieving module identity, you can also retrieve module status.

Item Description

Product type Module’s product type, such as digital I/O or analog I/O

Product code Module’s catalog number

Major revision Module’s major revision number

Minor revision Module’s minor revision number

Status Module’s statu s, including these items:

• Controller ownership

• Whether the module has been configured

• Device-specific status, such as the following: – Self-test – Update in progress – Communications fault – Not owned (outputs in Program mode) – Internal fault (needs update) – Run mode – Program mode (outputs only)

• Minor recoverable fault

• Minor unrecoverable fault

• Major recoverable fault

• Major unrecoverable fault

Vendor Module’s manufacturer vendor, such as Allen-Bradley

Serial number Module’s serial number

Length of ASCII text string Number of characters in module’s text string

ASCII text string Module’s ASCII text string description

IMPORTANT

You must perform a WHO service to retrieve this information. For more information, refer to page 228

18 Rockwell Automation Publication 1756-UM058G-EN-P - November 2012

Chapter 1 What Are ControlLogix Digital I/O Modules?

Notes:

Rockwell Automation Publication 1756-UM058G-EN-P - November 2012 19

Chapter 2

Digital I/O Operation in the ControlLogix System

I/O modules are the interface between controllers and field devices in a ControlLogix system. Digital I/O modules transfer data to devices that require just one bit to be represented (0 or 1). For example, a switch is open or closed, or a light is on or off.

Top ic Pa ge

Ownership 20

Use RSNetWorx and RSLogix 5000 Software 20

Internal Module Operation 21

Connec tions 23

Input Module Operation 26

Input Modules in a Local Chassis 27

Input Modules in a Remote Chassis 28

Output Module Operation 31

Output Modules in a Local Chassis 31

Output Modules in a Remote Chassis 32

Listen-only Mode 34

Multiple Owner-Controllers of Input Modules 34

Configuration Changes in an Input Module with Multiple Owners 35

20 Rockwell Automation Publication 1756-UM058G-EN-P - November 2012

Chapter 2 Digital I/O Operation in the ControlLogix System

Ownership

I/O modules in a ControlLogix system can be owned by an RSLogix™ 5000 controller. An owner-controller fulfills these functions:

• Stores configuration data for every module that it owns

• Sends I/O modules configuration data to define module behavior and

begin module operation with the control system

• Resides in a local or remote chassis in regard to the I/O module’s position

Each ControlLogix I/O module must continuously maintain communication with its owner-controller to operate normally.

Typically, each module in the system will have only one owner-controller. Input modules can have more than one owner-controller. Output modules, however, are limited to a single owner-controller.

For more information about using multiple owner-controllers, see Configuration

Changes in an Input Module with Multiple Owners on page 35.

Use RSNetWorx and RSLogix 5000 Software

The I/O configuration within RSLogix 5000 software generates the configuration data for each I/O module in the control system, including modules in a remote chassis. A remote chassis contains the I/O module but not the module’s owner-controller. A remote chassis can be connected to the controller via an EtherNet/IP network or a scheduled connection on the ControlNet network.

Configuration data from RSLogix 5000 software is transferred to the controller during the program download and subsequently transferred to I/O modules. The I/O modules in the local or remote chassis are ready to run as soon as the configuration data has been downloaded. However, to enable scheduled connections to I/O modules on the ControlNet network, you must schedule the network by using RSNetWorx™ for ControlNet software.

RSNetWorx software transfers configuration data to I/O modules on a scheduled ControlNet network and establishes a network update time (NUT) for the ControlNet network that is compliant with the desired communication options specified for each module during configuration.

Anytime a controller references a scheduled connection to I/O modules on a scheduled ControlNet network, you must run RSNetWorx software to configure the ControlNet network.

Rockwell Automation Publication 1756-UM058G-EN-P - November 2012 21

Digital I/O Operation in the ControlLogix System Chapter 2

Refer to the following general steps when configuring I/O modules.

1. Configure all I/O modules for a given controller by using RSLogix 5000 software and download that information to the controller.

2. If the I/O configuration data references a scheduled connection to a module in a remote chassis connected via the ControlNet network, run RSNetWorx for ControlNet software to schedule the network.

3. After running RSNetWorx software, perform an online save of the RSLogix 5000 project to make sure the configuration information that RSNetWorx software sends to the controller is saved.

Internal Module Operation

ControlLogix I/O modules experience signal propagation delays that must be accounted for during operation. Some of these delays are user-configurable, and some are inherent to the module hardware.

For example, there is a small delay, typically less than 1 ms, between when a signal is applied at the RTB of a ControlLogix input module and when a signal is sent to the system over the backplane. This time reflects a filter time of 0 ms for a DC input.

This section offers an explanation of the time limitations with ControlLogix I/O modules.

Input Modules

As shown in the illustration below, ControlLogix input modules receive a signal at the RTB and process it internally through hardware, filters, and an ASIC scan before sending a signal to the backplane via the requested packet interval (RPI) or at a Change of State (COS) occurrence. The RPI is a configured interval of time that determines when a module’s data is sent to the controller.

IMPORTANT

You must run RSNetWorx for ControlNet software whenever a new I/O module is added to a scheduled ControlNet chassis. When a module is permanently removed from a remote chassis, we recommend that you run RSNetWorx for ControlNet software to reschedule the network and optimize the allocation of network bandwidth.

42701

Hardware Delay

Filter Delay

ASIC Delay

Signal Applied at the RTB

Signal Sent to the Backplane

22 Rockwell Automation Publication 1756-UM058G-EN-P - November 2012

Chapter 2 Digital I/O Operation in the ControlLogix System

The table defines some of the delay factors that affect the signal propagation on an I/O module.

Output Modules

ControlLogix output modules receive a signal from the controller and process it internally via hardware and an ASIC scan before sending a signal to the output device via the RTB.

Delay Description

Hardware How the module is configured and the variance between the type of modules affects

how the signal is processed.

Filter User configuration varies between modules, thus affecting the signal propagation.

ASIC ASIC scan = 200 µs.

EXAMPLE

A typical delay time can be estimated despite the number of factors that might contribute. For example, if you are turning on a 1756-IB16 module at 24V DC in 25 °C (77 °F) conditions, the signal propagation delay is affected by these factors:

• Hardware delay to energize the input (typically 290 µs on the 1756-IB16 module)

• User-configurable filter time of 0, 1, or 2 ms

• ASIC scan of 200 µs

In the worst case scenario with a filter time of 0 ms, the 1756-IB16 module has a 490 µs signal propagation delay.

These times are not guaranteed. For nominal and maximum delay times for each module, see the 1756 ControlLogix I/O Modules Specifications Technical Data, publication 1756-TD002

Hardware DelayASIC Delay

42702

Signal Sent from RTB Output Point

Signal Received from Controller

Rockwell Automation Publication 1756-UM058G-EN-P - November 2012 23

Digital I/O Operation in the ControlLogix System Chapter 2

The table defines some of the delay factors that affect the signal propagation on an I/O module.

Connections

With ControlLogix I/O modules, a connection is the data transfer link between a controller and an I/O module. A connection can be one of these types:

• Direct

• Rack-optimized

The table lists the advantages and disadvantages of each connection type.

Delay Description

Hardware How the module is configured and the variance between the type of modules affects

how the signal is processed.

ASIC ASIC scan = 200 µs.

EXAMPLE

A typical delay time can be estimated despite the number of factors that might contribute. For example, if you are turning on a 1756-OB16E module at 24V DC in 25 °C (77 °F) conditions, the signal propagation delay is affected by these factors:

• Hardware delay to energize the input (typically 70 µs on the 1756-OB16E module)

• ASIC scan of 200 µs

In the worst case scenario with a filter time of 0 ms, the 1756-OB16E module has a 270 µs signal propagation delay.

These times are not guaranteed. See Chapter 8

for nominal and maximum

delay times for each module.

Connection Type Advantages Dis advantages

Direct All input and data echo information is

transferred, including diagnostic information and fusing data.

With more data transferring over the network, your system does not operate as efficiently as with rack connections.

Rack-optimized Connection usage is economized. The

owner-controller has a single RPI value for each connection.

Input and data echo information is limited to general faults and data.

24 Rockwell Automation Publication 1756-UM058G-EN-P - November 2012

Chapter 2 Digital I/O Operation in the ControlLogix System

Direct Connections

A direct connection is a real-time data transfer link between the controller and the device that occupies the slot that the configuration data references. When module configuration data is downloaded to an owner-controller, the controller attempts to establish a direct connection to each of the modules referenced by the data.

If a controller has configuration data referencing a slot in the control system, the controller periodically checks for the presence of a device there. When a device’s presence is detected there, the controller automatically sends the configuration data.

If the data is appropriate to the module found in the slot, a connection is made and operation begins. If the configuration data is not appropriate, the data is rejected and an error message appears in the software. In this case, the configuration data can be inappropriate for any of a number of reasons. For example, a module’s configuration data may be appropriate except for a mismatch in electronic keying that prevents normal operation.

The controller maintains and monitors its connection with a module. Any break in the connection causes the controller to set fault status bits in the data area associated with the module. Breaks in the connection can be caused by a module fault or the removal of the module from the chassis while under power. RSLogix 5000 software monitors fault status bits to annunciate module failures.

Rack-optimized Connections

When a digital I/O module is located in a remote chassis with respect to its owner-controller, you can choose Rack Optimization or Listen-only Rack Optimization during module configuration. The option you choose depends on the communication module configuration. If the communication module uses Listen-only Rack Optimization, then the I/O module must also use Listen-only Rack Optimization.

A rack-optimized connection economizes bandwidth between owner-controllers and digital I/O modules in the remote chassis. Rather than having several direct connections with individual RPI values, an owner-controller has a single rack connection with a single RPI value. That RPI value accommodates all digital I/O modules in the remote chassis.

Rockwell Automation Publication 1756-UM058G-EN-P - November 2012 25

Digital I/O Operation in the ControlLogix System Chapter 2

The input, or data echo, information is limited to general faults and data. No additional status, such as diagnostic information, is available.

The illustration below shows how a rack-optimized connection eliminates the need for three separate connections. The owner-controller in the local chassis communicates with all the I/O modules in the remote chassis but uses only one connection. The ControlNet communication module sends data from the modules simultaneously at the RPI.

Figure 2 - Rack-optimized Connection

IMPORTANT

Because rack-optimized connections are applicable only in applications that use a remote chassis, you must configure the communication format , as described in Chapter 7

, for both the remote I/O module and the remote

1756-CNB module or EtherNet/IP module.

Make sure you configure both modules for rack optimization. If you choose a different communication format for each module, the controller makes two connections to the same chassis (one for each format) and the same data travels across the ControlNet network.

If you use rack optimization for both modules, you preserve bandwidth and configure your system to operate more efficiently.

IMPORTANT

Each controller can establish connections, in any combination of direct or rackoptimized. In other words, you can use a rack-optimized connection between an owner-controller and multiple remote I/O modules while simultaneously using a direct connection between that same controller and any other I/O modules in the same remote chassis.

Local Chassis

Remote Chassis

ControlNet Network

41021

One Connection for

All Remote I/O

26 Rockwell Automation Publication 1756-UM058G-EN-P - November 2012

Chapter 2 Digital I/O Operation in the ControlLogix System

Suggestions for Rack-optimized Connections

We recommend that you use a rack-optimized connection for these applications:

• Standard digital I/O modules

• Non-fused digital output modules

• Owner-controllers running low on connections

Input Module Operation

In traditional I/O systems, controllers poll input modules to obtain their input status. In the ControlLogix system, a controller does not poll digital input modules. Instead, the modules multicast their data either upon change of state (COS) or requested packet interval (RPI). The frequency depends on the options chosen during configuration and whether the input module is local or remote. This method of communication uses the Producer/Consumer model. The input module is the producer of input data and the controller is the consumer of the data.

All ControlLogix inputs are updated asynchronously in relation to the controller’s task execution. In other words, an input may be updated in the controller at any time during the controller’s execution of the tasks it is configured to run. The input device determines when the input is sent based on its configuration.

An input module’s behavior also varies depending upon whether it operates in the local chassis or in a remote chassis. The following sections detail the differences in data transfers between local and remote installations.

IMPORTANT

Rack-optimized connections are available only to digital I/O modules. However, do not use a rack-optimized connection for diagnostic I/O modules or fused output modules. Diagnostic and fused output data will not be transferred over a rack-optimized connection. This defeats the purpose of using those modules.

Rockwell Automation Publication 1756-UM058G-EN-P - November 2012 27

Digital I/O Operation in the ControlLogix System Chapter 2

Input Modules in a Local Chassis

When a module resides in the same chassis as the owner-controller, the following two configuration parameters affect how and when an input module multicasts data:

• Requested packet interval (RPI)

• Change of state (COS)

RPI

The RPI defines the slowest rate at which a module multicasts its data to the owner-controller. The time ranges from 200 µs…750 ms and is sent to the module with all other configuration parameters. When the specified time frame elapses, the module will multicast data. This is also called a cyclic update.

COS

COS instructs the module to transfer data whenever a specified input point transitions from On to Off or Off to On. The transition is referred to as a change of state.

COS configuration occurs on a per-point basis, but all module data is multicast when any point enabled for COS changes state. COS is more efficient than RPI because it multicasts data only when a change occurs.

For example, if an input is changing state consistently every two seconds and the RPI is set at 750 ms, the data transfer will look like the illustration.

IMPORTANT

The module’s COS feature defaults to Enabled for both On to Off and Off to On.

IMPORTANT

You must specify an RPI regardless of whether you enable COS. If a change does not occur within the RPI timeframe, the module still will multicast data at the rate specified by the RPI.

41381

= COS Multicast

= RPI Multicast

250 500 750

1 Second

1250 1500 1750

2 Seconds 3 Seconds

2250 2500 2750 3250

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Chapter 2 Digital I/O Operation in the ControlLogix System

Because the RPI and COS functions are asynchronous to the program scan, it is possible for an input to change state during program scan execution. The point must be buffered to prevent this from occurring. To buffer the point, you can copy the input data from your input tags to another structure and use the data from there.

Trigger Event Tasks

When configured, ControlLogix digital input modules can trigger an event task. The event task lets you execute a section of logic immediately when an event, or receipt of new data, occurs.

Your ControlLogix digital I/O module can trigger event tasks whenever module input data changes state. Refer to these considerations when using a digital input module to trigger an event task:

• Only one input module can trigger a specific event task.

• Input modules trigger the event task based on the module’s COS

configuration. The COS configuration defines which points prompt the module to produce data if they turn On or Off. This production of data triggers the event task.

• Typically, enable COS for only one point on the module. If you enable COS for multiple points, a task overlap of the event task may occur.

For more information on event tasks, refer to the Logix5000 Controllers Tasks, Programs, and Routines Programming Manual, publication 1756-PM005

Input Modules in a Remote Chassis

If an input module physically resides in a chassis other than where the owner-controller resides, the role of the RPI and the module’s COS behavior changes slightly with respect to getting data to the owner.

The RPI and COS behavior still define when the module will multicast data within its own chassis, as described in the previous section. But, only the value of the RPI determines when the owner-controller will receive it over the network.

TIP

To minimize traffic and conserve bandwidth, use a larger RPI value if COS is enabled and the module is in the same chassis as its owner-controller.

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Digital I/O Operation in the ControlLogix System Chapter 2

Remote Input Modules Connected via the ControlNet Network

When an RPI value is specified for an input module in a remote chassis connected by a scheduled ControlNet network, in addition to instructing the module to multicast data within its own chassis, the RPI also reserves a spot in the stream of data flowing across the ControlNet network.

The timing of this reserved spot may or may not coincide with the exact value of the RPI. But, the control system will guarantee that the owner-controller will receive data at least as often as the specified RPI.

As shown in the illustration below, the input data within the remote chassis is multicast at the configured RPI. The ControlNet communication module sends input data back to the owner-controller at least as often as the RPI.

Figure 3 - Remote Input Modules on ControlNet Network

The module’s RPI and reserved spot on the network are asynchronous to each other. This means there are best and worst case scenarios as to when the owner-controller will receive updated data from the module in a remote chassis.

Best Case RPI Multicast Scenario

In the best case scenario, the module performs an RPI multicast with updated channel data just before the reserved network slot is made available. In this case, the remotely-located owner receives the data almost immediately.

40947

ControlNet Network

Local Chassis Remote Chassis

Multicast Data

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Chapter 2 Digital I/O Operation in the ControlLogix System

Worst Case RPI Multicast Scenario

In the worst case scenario, the module performs an RPI multicast just after the reserved network slot has passed. In this case, the owner-controller will not receive data until the next available network slot.

When selecting values for the remotely located module’s RPI, system throughput is optimized when its RPI value is a power of two times the current NUT running on the ControlNet network.

For example, the following table shows recommended RPI values for a system by using a NUT of 5 ms.

Remote Input Modules Connected via the EtherNet/IP Network

When remote digital input modules are connected to the owner-controller via an EtherNet/IP network, data is transferred to the owner-controller at these times:

• At the RPI, the module produces data within its own chassis.

• At the COS (if enabled), the 1756 EtherNet/IP communication module

in the remote chassis immediately sends the module’s data over the network to the owner-controller as long as it has not sent data within a timeframe that is one-quarter the value of the digital input module’s RPI. This prevents flooding the network with data.

For example, if a digital input module uses an RPI = 100 ms, the EtherNet/IP module sends module data immediately on receiving it if another data packet was not sent within the last 25 ms.

For more information about specifying an RPI rate, see the Logix5000 Controllers Design Considerations Reference Manual, publication 1756-RM094

IMPORTANT

Enabling the COS feature on an input module in a remote chassis allows the module to multicast data at both the RPI rate and when the input changes state. This helps to reduce the worst case time.

Table 2 - Recommended RPI Values for System by Using NUT of 5 ms

NUT=5 ms x2

Optimal RPI Valu es ( ms)

5 ms 10 ms 20 ms 40 ms 80 ms 160 ms 320 ms 640 ms

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Digital I/O Operation in the ControlLogix System Chapter 2

Output Module Operation

An owner-controller sends output data to an output module when either one of two things occur:

• At the end of every one of its tasks (local chassis only)

• At the rate specified in the module’s RPI

When an output module physically resides in a remote chassis with respect to the owner-controller, the owner-controller sends data to the output module only at the RPI rate specified for the module. Updates are not performed at the end of the owner-controller’s tasks.

Whenever the module receives data from the controller, it immediately multicasts the output commands it received to the rest of the system. The actual output data is echoed by the output module as input data and multicast back out onto the network. This is called output data echo.

Output Modules in a Local Chassis

The owner-controller updates ControlLogix digital output modules in the local chassis at the end of every task and at the RPI.

When you specify an RPI value for a digital output module, you instruct the owner-controller when to broadcast the output data to the module. If the module resides in the same chassis as the owner-controller, as shown in the illustration below, the module receives the data almost immediately after the ownercontroller sends it. Backplane transfer times are small.

Figure 4 - Local Output Modules

Depending on the value of the RPI with respect to the length of the program scan, the output module can receive and echo data multiple times during one program scan.

IMPORTANT

In this Producer/Consumer model, the output module is the consumer of the controller’s output data and the producer of the data echo.

40949

Data is sent at the end of every task and at the RPI.

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Chapter 2 Digital I/O Operation in the ControlLogix System

Output Modules in a Remote Chassis

If an output module physically resides in a chassis other than that of the owner-controller, the owner-controller normally sends data to the output module at the RPI rate specified. Updates are not performed at the end of the controller’s tasks.

In addition, the role of the RPI for a remote output module changes slightly with respect to getting data from the owner-controller.

Remote Output Modules Connected via the ControlNet Network

When an RPI value is specified for an output module in a remote chassis connected to the owner-controller by a scheduled ControlNet network, in addition to instructing the owner-controller to multicast the output data within its own chassis, the RPI also reserves a spot in the stream of data flowing across the ControlNet network.

The timing of this reserved spot may or may not coincide with the exact value of the RPI. But, the control system will guarantee that the output module will receive data at least as often as the specified RPI, as shown in the illustration below.

Figure 5 - Remote Output Modules on ControlNet Network

The reserved spot on the network and the output data sent by the controller are asynchronous to each other. This means there are best and worst case scenarios as to when the owner-controller will receive updated data from the module in a remote chassis.

Best Case RPI Multicast Scenario

In the best case scenario, the owner-controller sends the output data just before the reserved network slot is made available. In this case, the remote output module receives the data almost immediately.

42675

ControlNet Network

Local Chassis Remote Chassis

Data is sent from t he owner-co ntroller.

Output data is sent at least as often as RPI.

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Digital I/O Operation in the ControlLogix System Chapter 2

Worst Case RPI Multicast Scenario

In the worst case scenario, the owner-controller sends the output data just after the reserved network slot has passed. In this case, the output module does not receive data until the next available network slot.

Remote Output Modules Connected via the EtherNet/IP Network

When remote digital output modules are connected to the owner-controller via an EtherNet/IP network, the controller sends output data at these times:

• When the RPI timer expires

• When an Immediate Output (IOT) instruction, if programmed, is

executed

An IOT sends data immediately and resets the RPI timer.

• When a new schedule is created for a 1756-OB16IEFS module from the motion planner for a cam that has been armed by an MAOC instruction

Because the 1756-OB16IEFS module is the only 1756 module that can be used in a remote chassis with the MAOC instruction, it is the only module that receives output data in this scenario

IMPORTANT

These best and worst case scenarios indicate the time required for output data to transfer from the owner-controller to the module once the owner-controller has produced it. They do not take into account the user program time in the owner-controller.

The receipt of new data is a function of the length of the user program and its asynchronous relationship with the RPI.

The owner-controller updates remote output modules at the end of each task as well as at the RPI, as described earlier in this section, if your application uses these components:

• 1756-CNB/D or 1756-CNBR/D modules

• RSLogix 5000 software, version 8.02.00 or later

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Chapter 2 Digital I/O Operation in the ControlLogix System

Listen-only Mode

Any controller in the system can listen to the data from any I/O module, such as input data, echoed output data, or echoed diagnostic information. Even if a controller does not own a module, or hold the module’s configuration data, the controller can still listen to the module.

During the module configuration process, you can specify one of several Listen modes. For more information, see Communication or Connection Formats

page 131.

Choosing a Listen mode allows the controller and module to establish communication without the controller sending any configuration data. In this instance, another controller owns the module being listened to.

Multiple Owner-Controllers of Input Modules

If a connection is lost between an owner-controller and a module, the connection is also lost between any controllers listening to that module. As a result, the ControlLogix system lets you define more than one owner-controller for input modules.

In the illustration below, controller A and controller B both have been config ured to be owner-controllers of the same input module.

Figure 6 - Identical Owner-Controller Configurations for Input Module

IMPORTANT

In Listen-only mode, controllers continue to receive data multicast from the I/O module as long as the connection between the owner-controller and I/O module is maintained.

If the connection between the owner-controller and module is broken, the module stops multicasting data and connections to all listening controllers are also broken.

IMPORTANT

Only input modules can have multiple owner-controllers. If multiple ownercontrollers are connected to the same input module, they must maintain identical configurations for that module.

Input Module Configuration Data

Xxxxx Xxxxx Xxxxx

Input Module Configuration Data

Xxxxx Xxxxx Xxxxx

41056

Initial Configuration Initial Configuration

Input

A B

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Digital I/O Operation in the ControlLogix System Chapter 2

As soon as a controller receives its user program, it will try to establish a connection with the input module. A connection is established with the controller whose configuration data arrives first. When the second controller’s configuration data arrives, the module compares it to its current configuration data, which was received and accepted from the first controller.

If the configuration data sent by the second controller matches the data sent by the first controller, that connection is also accepted. If any parameter of the second configuration data is different from the first, the module rejects the connection and the user is informed by an error in the software or via program logic.

The advantage of multiple owners over a Listen-only connection is that either of the controllers can break the connection to the module, and the module will continue to operate and multicast data to the system through the connection maintained by the other controller.

Configuration Changes in an Input Module with Multiple Owners

You must be careful when changing an input module’s configuration data in a multiple owner scenario. If the configuration data is changed in owner A and sent to the module, that configuration data is accepted as the new configuration for the module. Owner B will continue to listen unaware that any changes have been made in the module’s behavior, as illustrated below.

Figure 7 - Module Configuration Changes with Multiple Owners

41057

Input Module Configuration Data

Xxxxx

Zzzzz

Xxxxx

Input Module Configuration Data

Xxxxx

Initial Configuration Initial Configuration

A BInput

IMPORTANT

A message in RSLogix 5000 software alerts you to the possibility of a multiple owner-controller situation and lets you inhibit the connection before changing the module’s configuration. When changing the configuration for a module with multiple owners, we recommend the connection be inhibited.

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Chapter 2 Digital I/O Operation in the ControlLogix System

To prevent other owner-controllers from receiving potentially erroneous data, use these steps when changing a module’s configuration in a multiple owner scenario while online.

1. For each owner-controller, inhibit the connection to the module either in the software on the Connection tab or the message dialog box warning you of the multiple owner condition.

2. Make the appropriate configuration data changes in the software. For more information about using RSLogix 5000 software to change the configuration, see Chapter

3. Repeat step 1

and step 2 for all owner-controllers, making the exact same

changes in each.

4. Clear the Inhibit checkbox in each owner-controller configuration.

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Chapter 3

Common Module Features

Input Module Compatibility

ControlLogix digital input modules interface to sensing devices and detect whether they are On or Off.

ControlLogix input modules convert AC or DC On/Off signals from user devices to appropriate logic level for use within the processor. Typical input devices include the following:

• Proximity switches

• Limit switches

• Selector switches

• Float switches

• Push button switches

When designing systems with ControlLogix input modules, consider these factors:

• Voltage necessary for your application

• Current leakage

• Whether you need a solid state device

• Whether your application should use sinking or sourcing wiring

Top ic P age

Input Module Compatibility 37

Output Module Compatibility 38

Common Features 39

Common Features Specific to Input Modules 50

Common Features Specific to Output Modules 54

Fault and Status Reporting between Input Modules and Controllers 64

Fault and Status Reporting between Output Modules and Controllers 65

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Chapter 3 Common Module Features

Output Module Compatibility

ControlLogix output modules can be used to drive a variety of output devices. Typical output devices compatible with ControlLogix outputs include these items:

• Motor starters

• Solenoids

• Indicators

Follow these guidelines when designing a system:

• Make sure that the ControlLogix outputs can supply the necessary surge and continuous current for proper operation.

• Make sure that the surge and continuous current are not exceeded. Damage to the module could result.

When sizing output loads, refer to the documentation supplied with the output device for the surge and continuous current needed to operate the device.

The ControlLogix standard digital outputs are capable of directly driving the ControlLogix standard digital inputs. The exceptions are the AC and DC diagnostic input modules. When diagnostics are used, a shunt resistor is required for leakage current.

For information on the compatibility of motor starters with ControlLogix output modules, see Appendix

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Common Module Features Chapter 3

Common Features

The table below lists features common to all ControlLogix digital I/O modules.

Removal and Insertion Under Power

All ControlLogix I/O modules may be inserted and removed from the chassis while power is applied. This feature allows greater availability of the overall control system. While the module is being removed or inserted, there is no additional disruption to the rest of the control process. This helps prevent an entire production line from having to be shut down.

Module Fault Reporting

ControlLogix digital I/O modules provide both hardware and software indication when a module fault has occurred. Each module’s fault status indicator and RSLogix 5000 software will graphically display this fault and include a fault message describing the nature of the fault.

This feature lets you determine how your module has been affected and what action should be taken to resume normal operation.

The 1756-OB16IEF module extends this feature by enabling you to define the duration of time before the module transitions to On or Off after a fault occurs. For more information, see Programmable Fault State Delays

on page 95.

Top ic Pag e

Removal and Insertion Under Power 39

Module Fault Reporting 39

Software Configurable 40

Electronic Keying 40

Module Inhibiting 46

Use the System Clock to Timestamp Inputs and Schedule Outputs 47

Producer/Consumer Communication 50

Status Indicator Information 50

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Chapter 3 Common Module Features

Software Configurable

RSLogix 5000 software provides an interface to configure each module. All module features are enabled or disabled through the I/O configuration within the software.

You can also use the software to retrieve the following information from any module in the system:

• Serial number

• Firmware revision information

• Product code

• Ve n d o r

• Error and fault information

• Diagnostic counters

By eliminating tasks, such as setting hardware switches and jumpers, the software makes module configuration easier and more reliable.

Electronic Keying

The electronic keying feature automatically compares the expected module, as exists in the RSLogix 5000 I/O Configuration tree, to the physical module in the chassis before I/O communication begins. You can use electronic keying to help prevent communication to a module that does not match the type and revision expected.

For each module in the I/O Configuration tree, the user-selected keying option determines if and how an electronic keying check is performed. Typically, three keying options are available:

• Exact Match

• Compatible Keying

• Disable Keying

You must carefully consider the benefits and implications of each keying option when selecting between them. For some specific module types, fewer options are available.

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Common Module Features Chapter 3

Electronic keying is based on a set of attributes unique to each product revision. When a Logix5000 controller begins communicating with a module, this set of keying attributes is considered.

You can find revision information on the General tab of a module’s Properties dialog box.

Figure 8 - General Tab

Exact Match

Exact Match keying requires all keying attributes, that is, Vendor, Product Type, Product Code (catalog number), Major Revision, and Minor Revision, of the physical module and the module created in the software to match precisely to establish communication. If any attribute does not match precisely, I/O communication is not permitted with the module or with modules connected through it, as in the case of a communication module.

Use Exact Match keying when you need the system to verify that the module revisions in use are exactly as specified in the project, such as for use in highlyregulated industries. Exact Match keying is also necessary to enable Automatic Firmware Update for the module via the Firmware Supervisor feature from a Logix5000 controller.

Attribute Description

Vendor The manufacturer of the module, for example, Allen-Bradley.

Product Type The general type of the module, for example, communication adapter, AC drive, or digital I/O.

Product Code The specific type of module, generally represented by its cat alog number, suc h as 1756-IB16I.

Major Revision A number that represents the functional capabilities and data exchange formats of the

module. Typically, a later major revision supports at least all of the data formats supported by an earlier major revision of the same catalog number.

Minor Revision A number that indicates the module’s spec ific firmware revision. Minor revisions typically do

not impact data compatibility but may indicate performance or behavior improvement.

IMPORTANT

Changing electronic keying selections online may cause the I/O communication connection to the module to be disrupted and may result in a loss of data

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Chapter 3 Common Module Features

Compatible Keying

Compatible Keying indicates that the module determines whether to accept or reject communication. Different module families, communication adapters, and module types implement the compatibility check differently based on the family capabilities and on prior knowledge of compatible products.

Compatible Keying is the default setting. Compatible Keying allows the physical module to accept the key of the module configured in the software, provided that the configured module is one the physical module is capable of emulating. The exact level of emulation required is product and revision specific.

With Compatible Keying, you can replace a module of a certain Major Revision with one of the same catalog number and the same or later, that is higher, Major Revision. In some cases, the selection makes it possible to use a replacement that is a different catalog number than the original. For example, you can replace a 1756-CNBR module with a 1756-CN2R module.

Release notes for individual modules indicate the specific compatibility details.

EXAMPLE

In the following scenario, Exact Match keying prevents I/O communication.

The module configuration is for a 1756-IB16D module with module revision

3.1. The physical module is a 1756-IB16D module with module revision 3.2. In this case, communication is prevented because the Minor Revision of the module does not match precisely.

IMPORTANT

Changing electronic keying selections online may cause the I/O Communication connection to the module to be disrupted and may result in a loss of data.

Module Configuration

Vendor = Allen-Bradley Product Type = Digital Input Module Catalog Number = 1756-IB16D Major Revision = 3

Minor Revision = 1

Physical Module

Vendor = Allen-Bradley Product Type = Digital Input Module Catalog Number = 1756-IB16D Major Revision = 3

Minor Revision = 2

Communication is prevented

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Common Module Features Chapter 3

When a module is created, the module developers consider the module’s development history to implement capabilities that emulate those of the previous module. However, the developers cannot know future developments. Because of this, when a system is configured, we recommend that you config ure your module by using the earliest, that is, lowest, revision of the physical module that you believe will be used in the system. By doing this, you can avoid the case of a physical module rejecting the keying request because it is an earlier revision than the one configured in the software.

EXAMPLE

In the following scenario, Compatible Keying prevents I/O communication.

The module configuration is for a 1756-IB16D module with module revision

3.3. The physical module is a 1756-IB16D module with module revision 3.2. In this case, communication is prevented because the minor revision of the module is lower than expected and may not be compatible with 3.3.

Module Configuration

Vendor = Allen-Bradley Product Type = Digital Input Module Catalog Number = 1756-IB16D Major Revision = 3

Minor Revision = 3

Physical Module

Vendor = Allen-Bradley Product Type = Digital Input Module Catalog Number = 1756-IB16D Major Revision = 3

Minor Revision = 2

Communication is prevented

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Chapter 3 Common Module Features

Disabled Keying

Disabled Keying indicates the keying attributes are not considered when attempting to communicate with a module. Other attributes, such as data size and format, are considered and must be acceptable before I/O communication is established. With Disabled Keying, I/O communication may occur with a module other than the type specified in the I/O Configuration tree with unpredictable results. We generally do not recommend using Disabled Keying.

If you use Disabled Keying, you must take full responsibility for understanding whether the module being used can fulfill the functional requirements of the application.

EXAMPLE

In the following scenario, Compatible Keying allows I/O communication.

The module configuration is for a 1756-IB16D module with module revision

2.1. The physical module is a 1756-IB16D module with module revision 3.2. In this case, communication is allowed because the major revision of the physical module is higher than expected and the module determines that it is compatible with the prior major revision.

IMPORTANT

Changing electronic keying selections online may cause the I/O communication connection to the module to be disrupted and may result in a loss of data.

ATT EN TI ON : Be extremely cautious when using Disabled Keying; if used incorrectly, this option can lead to personal injury or death, property damage, or economic loss.

Module Configuration

Vendor = Allen-Bradley Product Type = Digital Input Module Catalog Number = 1756-IB16D

Major Revision = 2 Minor Revision = 1

Physical Module

Vendor = Allen-Bradley Product Type = Digital Input Module Catalog Number = 1756-IB16D

Major Revision = 3 Minor Revision = 2

Communication is allowed

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Common Module Features Chapter 3

EXAMPLE

In the following scenario, Disable Keying prevents I/O communication.

The module configuration is for a 1756-IA16 digital input module. The physical module is a 1756-IF16 analog input module. In this case, communication is

prevented because the analog module rejects the data formats that the digital module configuration requests.

EXAMPLE

In the following scenario, Disable Keying allows I/O communication:

The module configuration is for a 1756-IA16 digital input module. The physical module is a 1756-IB16 digital input module. In this case, communication is allowed because the two digital modules share common data formats.

Module Configuration

Vendor = Allen-Bradley Product Type = Digital Input Module Catalog Number = 1756-IA16 Major Revision = 3 Minor Revision = 1

Physical Module

Vendor = Allen-Bradley Product Type = Analog Input Module Catalog Number = 1756-IF16 Major Revision = 3 Minor Revision = 2

Communication is prevented

Module Configuration

Vendor = Allen-Bradley Product Type = Digital Input Module Catalog Number = 1756-IA16 Major Revision = 2 Minor Revision = 1

Physical Module

Vendor = Allen-Bradley Product Type = Digital Input Module Catalog Number = 1756-IB16 Major Revision = 3 Minor Revision = 2

Communication is allowed

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Chapter 3 Common Module Features

Module Inhibiting

Module inhibiting lets you indefinitely suspend a connection between an owner-controller and a digital I/O module without having to remove the module from the configuration. This process lets you temporarily disable communication to a module, such as to perform maintenance. You can use module inhibiting in these ways:

• You write a configuration for an I/O module but inhibit the module to prevent it from communicating with the owner-controller. In this case, the owner does not establish a connection and the configuration is not sent to the module until the connection is uninhibited.

• In your application, a controller already owns a module, has downloaded the configuration to the module, and is currently exchanging data over the connection between the devices. In this case, you can inhibit the module and the owner-controller behaves as if the connection to the module does not exist.

You may need to use module inhibiting in these instances:

• Multiple controllers own the same digital input module. A change is required in the module’s configuration. However, the change must be made to the program in all controllers. In this case, you follow these steps.

a. Inhibit the module. b. Change configuration in all controllers. c. Uninhibit the module.

• You want to upgrade a digital I/O module. We recommend you use this procedure.

a. Inhibit the module. b. Perform the upgrade. c. Uninhibit the module.

• You are using a program that includes a module that you do not physically possess yet, and you do not want the controller to continually look for a module that does not yet exist. In this case, you can inhibit the module in your program until it physically resides in the proper slot.

IMPORTANT

Changing electronic keying selections online may cause the I/O communication connection to the module to be disrupted and may result in a loss of data.

IMPORTANT

Whenever you inhibit an output module, it enters Program mode, and all outputs change to the state configured for Program mode. For example, if an output module is configured so that the state of the outputs transition to zero during Program mode, whenever that module is inhibited, outputs transition to zero.

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Common Module Features Chapter 3

Use the System Clock to Timestamp Inputs and Schedule Outputs

This section describes how to use CST timestamps in standard and diagnostic I/O modules and the CIP Sync timestamps in fast I/O modules.

Use Coordinated System Time with Standard and Diagnostic I/O Modules

Time masters generate a 64-bit coordinated system time (CST) for their respective chassis. The CST is a chassis-specific time that is not synchronized with, or in any way connected to, the time generated over the ControlNet network to establish a network update time (NUT). For more information about NUT, refer to Use RSNetWorx and RSLogix 5000 Software

on page 20.

You can configure your digital input modules to access the CST and timestamp input data with a relative time reference of when that input data changes state.

The following table describes how you can use CST timestamps.

IMPORTANT

Because only one CST value is returned to the controller when any input point changes state, we recommend that you use timestamping on only one input point per module.

Topic Description

Timestamping for a sequence of events

The CST can be used to establish a sequence of events occurring at a particular input module point by timestamping the input data. To determine a sequence of events, you must do the following:

• Set the input module’s communication format to CST Timestamped Input Data.

• Enable COS for the input point where a sequence will occur, and disable COS for all other

points on the module.

TIP

If you decide to configure multiple input points for COS, your module generates a unique CST each time any of those input points change state, as long as the changes do not occur within 500 s of each other.

If multiple input points configured for COS change state within 500 s of each other, a single CST value is generated for all making it appear that they changed at exactly the same time.

Timestamping in conjunction with scheduled outputs

Timestamping can be used in conjunction with the scheduled outputs feature, so that after input data changes state and a timestamp occurs, an output point will actuate at some configured time in the future.

You can schedule outputs up to 16 seconds into the future. When you use timestamping of inputs and scheduled outputs, you must do the following:

• Choose a communication or connection format for each input and output module that allows timestamping. For more information, refer to Communication or Connection

Forma ts on page 131.

• Have a time master in the same chassis as both I/O modules.

• Disable COS for all input points on the input module except the point being timestamped.

TIP

For scheduled outputs to work most effectively, remember the following items:

• The time to schedule outputs to transition in the future must account for any controller, backplane, and network delays.

• The I/O modules must reside in the same rack as the time master.

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Chapter 3 Common Module Features

Use CIP Sync Time with Fast I/O Modules

The 1756-IB16IF, 1756-OB16IEF, and 1756-OB16IEFS modules use CIP Sync for both timestamps and scheduling.

CIP Sync is a CIP implementation of the IEEE 1588 PTP (Precision Time Protocol). CIP Sync provides accurate real-time (Real-World Time) or Universal Coordinated Time (UTC) synchronization of controllers and devices connected over CIP networks. This technolog y supports highly distributed applications that require timestamping, sequence of events recording, distributed motion control, and increased control coordination.

The 1756-IB16IF, 1756-OB16IEF, and 1756-OB16IEFS modules are CIP Sync slave-only devices. There must be another module on the network that will function as a master clock. For more information on how to use CIP Sync technology, see the Integrated Architecture and CIP Sync Configuration Application Technique, publication IA-AT003

Fast I/O modules can be used to capture timestamps and schedule outputs like CST-based modules while providing the following advantages:

• Fast I/O modules have much higher precision than CST-based modules.

• Inputs are timestamped by point, so multiple inputs can be configured for

COS without losing timestamp data.

• CIP Sync is system wide, so timestamp and schedule values are consistent across all modules in the system. For instance, using 1756-IB16IF input timestamps to schedule outputs on a 1756-OB16IEF module means the controller, input module, and output module are not restricted to the same chassis as is the case with CST-based I/O.

• Output modules use all 64 bits of the timestamp to schedule, so there are no limits on schedule ranges.

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Common Module Features Chapter 3

Mixing CST and CIP Sync Modules in a ControlLogix System

CST is automatically enabled for each chassis that has been configured to use CIP Sync. Therefore, it is possible to include modules that use CST for their time base into systems that have been configured to use CIP Sync. Also, there is a direct correlation between CIP Sync system time and the local chassis CST time.

The CIP Sync system time and local chassis CST time are related by this equation:

CIP Sync system time = CST time + offset

The offset in the above equation is a value unique to each chassis and can be obtained by using one of these methods:

• CSTOffset from the Wall Clock Time (WCT) object of a controller in the chassis

• SystemOffset from the Time Synchronize object of a controller in the chassis

• LocalClockOffset returned in an I/O connection from a CIP Sync capable module in the chassis

The relationship described above enables CST and CIP Sync-based I/O to interoperate as long as the offset in the chassis containing the CST-based module is accessible.

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Chapter 3 Common Module Features

Producer/Consumer Communication

By using Producer/Consumer communication, ControlLogix I/O modules can produce data without first being polled by a controller. The modules produce the data and any other owner-controller device can decide to consume it.

For example, an input module produces data and any number of processors can consume the data at the same time. This eliminates the need for one processor to send the data to another processor. For more information about this process, see

Input Module Operation

on page 26.

Status Indicator Information

Each ControlLogix digital I/O module has a status indicator on the front of the module that lets you check the health and operational status of a module. The status indicator displays vary for each module.

See Appendix

A for examples of status indicators on ControlLogix digital I/O

modules.

Common Features Specific to Input Modules

The table below lists features specific to ControlLogix digital input modules.

Status Description

I/O status ST

This yellow display indicates the On/Off state of the field device. IMPORTANT: For the 1756-OA8D and 1756-OA8E modules, the I/O status indicator does not

illuminate without field power applied.

Module status OK

This green display indicates the module’s communication status.

Fault status FLT

This display is only found on some modules and indicates the presence or absence of various faults.

Fuse status Fuse

This display is only found on electronically fused modules and indicates the state of the module’s fuse.

Top ic Page

Data Transfer on Either Cyclic Time or Change of State 51

Set RPI 51

Enable Change of State 52

Software Configurable Filter Times 53

Isolated and Nonisolated Varieties of Input Modules 53

Multiple Input Point Densities 54

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Common Module Features Chapter 3

Data Transfer on Either Cyclic Time or Change of State

Digital input modules always send data at the RPI, but they send data at a change of state only if the COS feature is enabled. COS is more efficient than RPI because it multicasts data only when a change occurs.

The table describes the two ways a module sends data to the owner-controller.

Set RPI

The Connection tab on the Module Properties dialog box lets you enter an RPI. The RPI guarantees the slowest rate at which data is multicast.

The module’s actual data transfer rate may be faster than the RPI setting. But, the RPI provides a defined, maximum period of time when data is transferred to the owner-controller.

Follow these steps to set an RPI value.

1. On the Module Properties dialog box, click the Connection tab.

2. In the Requested Packet Interval (RPI) field, enter an RPI value.

3. Click OK.

Method Description

RPI A user-defined rate at which the module updates the information sent to its owner-controller.

This is also known as Cyclic Data Transfer.

COS Configurable feature that, when enabled, instructs the module to update its owner-controller

with new data whenever a specified input point transitions from On to Off and Off to On. The data will be sent at the RPI rate when there is no change of state. By default, this setting is always enabled for input modules.

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Chapter 3 Common Module Features

Enable Change of State

The Point column on the left side of the Configuration tab lets you set whether a COS occurs when a field device transitions from Off to On or On to Off.

Follow these steps to enable or disable COS.

1. On the Module Properties dialog box, click the Configuration tab.

2. Do one of the following in the Enable Change of State columns:

• To enable COS for a point, check the corresponding Off to On or On

to Off checkbox.

• To disable COS for a point, clear the corresponding Off to On or On to Off checkbox.

3. Click OK.

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Common Module Features Chapter 3

Software Configurable Filter Times

On to Off and Off to On filter times can be adjusted through RSLogix 5000 software for all ControlLogix input modules. These filters improve noise immunity within a signal. A larger filter value affects the length of delay times for signals from these modules.

Follow these steps to configure the input filter time.

1. On the right side of the Configuration tab, choose the input filter times from the Off

 On and On  O pull-down menus.

2. Click OK.

Isolated and Nonisolated Varieties of Input Modules

ControlLogix input modules provide isolated or nonisolated wiring options. Some applications require power for the I/O circuits to originate on separate, isolated power sources. Because these conditions require separate commons for each channel, some input modules use individual isolation, or point-to-point isolation so if one point faults, the others continue to operate.

Other types of isolation available with ControlLogix input modules are channelto-channel isolation and no isolation. Your application determines what type of isolation is necessary and which input module to use.

IMPORTANT

Input filters on the 1756-IB16IF module function differently than other digital I/O modules. For information about input filters on the 1756-IB16IF module, see page 90

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Chapter 3 Common Module Features

Multiple Input Point Densities

ControlLogix input modules use either 8-, 16-, or 32-point densities for greater flexibility in your application. A point is the termination where a wire attaches to the input module from a field device. The module receives information from the device to this designated point, thus signaling when activity occurs.

Common Features Specific to Output Modules

The table below lists features specific to ControlLogix digital output modules.

IMPORTANT

Some features are not available on all output modules. The table indicates which modules support each feature.

Topic Page Available Modules

Configurable Point-level Output States 55 All modules

Output Data Echo 56 All modules

Isolated and Nonisolated Varieties of Output Modules 56 All modules

Multiple Output Point Densities 57 All modules

Electronic Fusing 57 1756-OA8D

1756-OA8E 1756-OB16D 1756-OB16E 1756-OB8EI 1756-OB16IEF 1756-OB16IEFS 1756-OV16E 1756-OV32E

Field Power Loss Detection 60 1756-OA8E

Diagnostic Latch of Information 61 1756-OA8E

1756-OB16IEF 1756-OB16IEFS

Time-scheduled Output Control 63 1756-OB16IS

1756-OB16IEFS

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Common Module Features Chapter 3

Configurable Point-level Output States

Individual outputs can be configured to unique output states if the module goes into Program mode or Fault mode.

Follow these steps to configure an output state.

1. On the Module Properties dialog box, click the Configuration tab.

2. From the Program Mode pull-down menu, choose whether the module’s

output state is On or Off during Program mode:

• On

• Off

• Hold (Retain current output state)

3. From the Fault Mode pull-down menu, choose whether the module’s

output state during Fault mode:

• On

• Off

• Hold (Retain current output state)

4. Click OK.

IMPORTANT

Whenever you inhibit an output module, it enters Program mode, and all outputs change to the state configured for Program mode. For example, if an output module is configured so that the state of outputs turn Off during Program mode, whenever that module is inhibited, outputs turn Off.

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Chapter 3 Common Module Features

Output Data Echo

During normal operation, when a controller sends out an output command to the ControlLogix system, the output module that is targeted for that command returns the commanded state of the output to the system. This process verifies that the module has received the command and will try to execute it.

Other devices can use this broadcast signal through a Listen-only connection to determine the desired state of the output without having to interrogate the owner-controller.

Monitor Fault Bits

The output data echo only matches the commanded state of the outputs if the module is operating under normal conditions. If there is an anomaly with the module, the commanded state and the output data echo may not match.

You can monitor the fault bits for your output points for fault conditions. If a fault occurs, the fault bit is set and your program alerts you to the condition. In this case, the output data echo may not match the commanded state of the outputs.

If there is a mismatch between the commanded state of the outputs and the output data echo, check your output module for the following conditions:

• Communication fault.

• Connection is inhibited.

• Blown fuse—The module will not turn on an output if an overload or

short circuit is detected.

• (1756-OA8D and 1756-OA8E only) Loss of field power—The module will not turn on an output unless AC power is detected.

Isolated and Nonisolated Varieties of Output Modules

As with input modules, ControlLogix output modules provide isolated or nonisolated wiring options. I/O modules provide point-to-point, group-togroup, or channel-to-channel wiring isolation. Your specific application will determine what type of isolation is necessary and which output module to use.

IMPORTANT

Although some ControlLogix I/O modules provide nonisolated, field-side wiring options, each I/O module maintains internal electrical isolation between the system side and field side.

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Common Module Features Chapter 3

Multiple Output Point Densities

ControlLogix output modules use either 8-, 16-, or 32-point densities for greater flexibility in your application. A point is the termination where a wire attaches to the I/O module from a device. The I/O gets information from the device to this designated point, thus signaling when activity occurs.

Electronic Fusing

Some digital outputs have internal electronic or mechanical fusing to prevent too much current from flowing through the module. This feature protects the module from electrical damage. Other modules require external fusing.

Modules that use electronic fusing are fused on either a per point basis or per group basis to protect output points from the surge of too much current. If too much current begins to flow through a point, the fuse is tripped and a point-level fault is sent to the controller. A corresponding tag can be examined in the event of a fault. For more information about fault tags, see Appendix

These modules use electronic fusing:

• 1756-OA8E

• 1756-OB8EI

• 1756-OA8D

• 1756-OB16D

• 1756-OB16E

• 1756-OV16E

• 1756-OV32E

• 1756-OB16IEF

• 1756-OB16IEFS

Refer to Tab l e 3

to determine what fuse to use in your application. If your module does not support fusing, you can use a fused IFM to protect outputs. See publication 1492-TD008

Table 3 - Recommended Fuses

Circuit Type Cat. No. Fusing on the module Recommended Fuse Fuse Supplier

AC 1756-OA8

(1)

None—Fused IFM can be used to protect outputs

(9)

5x20mm

6.3A Medium lag

SAN-O Industry Corp. (SOC) p/n MT 4-6.3A

1756-OA8D

(2) (3)

Yes—Fused on a per point basis Electronically fused

1756-OA8E

(2) (3)

1756-OA16

(1) (4) (5)

Yes—Fused on a per group basis 5x20mm

3.15A Slo-Blow 1500A Interruption current

Littelfuse p/n H2153.15

1756-OA16I

(1)

None—Fused IFM can be used to protect outputs

(9)

5x20mm

6.3A Medium lag

SOC p/n MT 4-6.3A

1756-ON8

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Chapter 3 Common Module Features

DC 1756-OB8

(6)

None—Fused IFM can be used to protect outputs

(9)

5x20mm 4A Quick acting

SOC p/n MQ2-4A

1756-OB81

(6)

1756-OB8EI

(2) (3) (6)

Yes—Fused on a per point basis Electronically fused

1756-OB16D

(2) (3) (7)

1756-OB16E

(2) (3) (6)

Yes—Fused on a per group basis

1756-OB16I

(6) (8)

None—Fused IFM can be used to protect outputs

(9)

5x20mm 4A Quick acting

SOC p/n MQ2-4A

1756-OB16IEF

(2) (3) (6)

Yes—Fused on a per point basis Electronically fused

1756-OB16IEFS

(2) (3) (6)

1756-OB16IS

(6) (8)

None—Fused IFM can be used to protect outputs

(9)

5x20mm 4A Quick acting

SOC p/n MQ2-4A

1756-OB32

(6) (8)

5x20mm 800mA

Littelfuse p/n SP001.1003 or Schurter p/n

216.800

1756-OC8

(6)

5x20mm 4A Quick acting

SOC p/n MQ2-4A

1756-OG16

(6)

1756-OH8I

(6) (8)

1756-OV16E

(2) (3) (6)

Yes—Fused on a per group basis Electronically fused

1756-OV32E

(2) (3) (6)

Relay 1756-OW16I

(8)

None—Fused IFM can be used to protect outputs

(9)

5x20mm

6.3A Medium lag

SOC p/n MT 4-6.3A

1756-OX8I

(8)

(1) For voltages above 132V AC, the Interface Modules (IFM) are not an acceptable means to provide external fusing. A rated terminal block for the intended application must be used. (2) Electronic protection is not intended to replace fuses, circuit breakers, or other code-required wiring protection devices. (3) The electronic protection of this module has been designed to provide protection for the module from short-circuit conditions. The protection is based on a thermal cut-out principle. In the event of a

short-circuit condition on an output channel, that channel will limit the current within milliseconds after its thermal cut-out temperature has been reached. All other channels with a NUT of that group will continue to operate as directed by the module master (CPU, bridge, and so forth).

(4) A fuse is provided on each common of this module for a total of two fuses. The fuses are designed to protect the module from short circuit conditions. The fuse does not provide overload protection. In the

event of an overload on an output channel, it i s likely that the fuse will not blow and the output device associated with that channel will be damaged. To provide overload protection for your application,

user supplied fuses should be externally installed. (5) If a short circuit condition occurs on any channel within this module’s group, the entire group is turned Off. (6) The module does not provide protection against reverse polarity wiring or wiring to AC power sources. (7) The electronic protection of this module has been designed to provide protection for the module from short-circuit conditions. The protection is based on a thermal cut-out principle. In the event of a

short-circuit condition on an output channel, that channel will limit the current within milliseconds after its thermal cut-out temperature has been reached. Other channels could produce a false error on

the output verify fault signal due to the supply dropping below the minimum detect level of 19.2V DC. The output channels that are affected by this phenomena will continue to operate as directed by the

module master (CPU, bridge, and so forth). What this means is that the output verify fault signals of the other channels should be checked and reset if a short-circuit on one channel occurs. (8) The recommended fuse for this module has been sized to provide short circuit protection for wiring only to external loads. In the event of a short circuit on an output channel, it is likely that the transistor

or relay associated with that channel will be damaged and the module should be replaced or a spare output channel used for the load. The fuse does not provide overload protection. In the event of an

overload on an output channel, it is likely that the fuse will not blow and the transistor or relay associated with that channel will be damaged. To provide overload protection for your application, user

supplied fuse should be installed externally and properly sized to match the individual load characteristics. (9) The ControlLogix system has been agency certified using only the ControlLogix RTBs (1756-TBCH, 1756-TBNH, 1756-TBSH and 1756-TBS6H). Any application that requires agency certification of the

ControlLogix system using other wiring termination methods may require application specific approval by the certifying agency.

Table 3 - Recommended Fuses (continued)

Circuit Type Cat. No. Fusing on the module Recommended Fuse Fuse Supplier

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Common Module Features Chapter 3

You can reset an electronic fuse through RSLogix 5000 software during online monitoring or through program logic running on a controller. If your module uses point-level fusing, you can reset a fuse with a CIP Generic Message instruction, as described on page 227

Follow these steps to reset an electronic fuse through RSLogix5000 software during online monitoring.

1. On the Module Properties dialog box, click the Diagnostics tab.

The fields on the Diagnostic tab vary depending on whether your module supports fusing on a per point basis or a per group basis.

2. Click Reset for the output points for which to reset a fuse.

3. Click OK.

Fusing on a per group basis

Fusing on a per point basis

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Chapter 3 Common Module Features

Field Power Loss Detection

For the standard digital output modules, the Field Power Loss detection feature is found on the 1756-OA8E module only. When field power to the module is lost, or zero cross cannot be detected, a point-level fault is sent to the controller to identify the exact point faulted.

This feature has a corresponding tag that can be examined in the user program in the event of a fault. For information on these tags, see Chapter A

Follow these steps to enable or disable diagnostics for field power loss.

1. On the Module Properties dialog box, click the Configuration tab.

2. Do one of the following in the Enable Diagnostics for Field Power Loss

column:

• To enable field power loss detection for a specific point, check the corresponding check box.

• To disable field loss detection for a specific point, clear the corresponding checkbox.

3. Click OK.

IMPORTANT

Only enable Field Power Loss detection for points that are in use. If this feature is enabled for points that are not in use, you will receive faults for those points during operation.

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Common Module Features Chapter 3

Diagnostic Latch of Information

The diagnostic latch feature is available for the 1756-OA8E modules only. Diagnostic latching allows this module to latch a fault in the set position once it has been triggered, even if the error condition causing the fault to occur disappears.

Follow these steps to enable diagnostic latch of information.

1. On the Module Properties dialog box, click the Configuration tab.

2. Do one of the following in Enable Diag. Latching column:

• To enable diagnostic latching for a specific point, check the

corresponding checkbox.

• To disable diagnostic latching for a specific point, clear the corresponding checkbox.

3. Click OK.

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Chapter 3 Common Module Features

Latched diagnostic features can be cleared by using these methods:

• Reset Diagnostic Latch service

• Software reset during online monitoring

• Cycling power to the module’s

Follow these steps to a reset a latched fault through RSLogix 5000 software during online monitoring.

1. On the Modules Properties screen, click the Diagnostics tab.

2. In the Reset Latched Diagnostics column, click Reset next to the output

point for which to reset a latched fault.

3. Click OK.

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Common Module Features Chapter 3

Time-scheduled Output Control

Time-scheduled output control is available for these modules:

• 1756-OB16IS—Provides time-scheduled output control in CST time for outputs 0…7. Allows for schedules with a minimum interval of 100 µs.

• 1756-OB16IEFS—Provides time-scheduled output control in CIP Sync time for outputs 0…15. Allows for schedules with a minimum interval of 5µs.

By using the time-scheduled output control feature, the module can turn the outputs On or Off at a scheduled time. You can set the time for the output to turn On or Off in program logic. The modules manage the time locally, so that the output is turned On or Off at the specified time.

MAOC Instructions with Time-scheduled Output Control

The Motion Axis Output Cam (MAOC) instruction provides position-based control of outputs by using position and velocity information of any motion axis. When the 1756-OB16IS or 1756-OB16IEFS module is specified as the output destination for the MAOC instruction, the MAOC instruction automatically handles time-based scheduling for outputs. The benefit of using output scheduling in this manner is that the resolution of the output control is improved from the motion coarse update rate (typically 1…32 ms) to 100 µs for outputs 0…7 on the 1756-OB16IS module and 10 µs for outputs 0…15 on the 1756OB16IEFS module.

You can also use outputs 8…15 on the 1756-OB16IS module with the MAOC instruction. However, only outputs 0…7 have 100 µs resolution. Outputs 8…15 are updated at the motion coarse update rate.

For more information about using the MAOC instruction with scheduled output modules, refer to the Position-based Output Control with the MAOC Instruction Application Technique, publication 1756-AT017

Module Major Revision Considerations with Timestamping

When using timestamping for inputs or diagnostic timestamping of I/O modules, the following conditions may occur depending on the module’s major revision:

• If the module has a Major Revision = 1, it always returns a positive timestamping value.

• If the module has a Major Revision > 2, it returns a negative timestamping value until the module is synchronized with the owner-controller and the first change of state condition occurs.

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Chapter 3 Common Module Features

Use the Module Properties dialog box in RSLogix 5000 software to determine if the module has been synchronized with the owner-controller and whether the controller is synchronized with the CST. For more information on synchronizing owner-controllers and modules with the CST, see the ControlLogix System User Manual, publication 1756-UM001

Fault and Status Reporting between Input Modules and Controllers

ControlLogix digital input modules multicast fault and status data to any ownercontroller or listening controller. All input modules maintain a module-fault word, the highest level of fault reporting.

The table lists the fault word and the associated tag that can be examined in program logic to indicate when a fault has occurred for a standard input module.

All words are 32-bit, although only the number of bits appropriate for each module’s density are used. For example, the 1756-IA16I module has a modulefault word of 32 bits. But, because this is a 16-point module, only 16 bits (0…15) are used in the module-fault word.

The following illustration offers an overview of the fault reporting process on ControlLogix standard digital input modules.

Table 4 - Fault Word on Input Modules

Word Tag Name Description

Module-fault Fault Provides fault summary reporting. Available on all digital input

modules.

Table 5 - Bits Set in Module-fault Word

Condition Bits Set

Communication fault All 32 bits are set to 1, regardless of the module’s density.

Module-fault Word

All Modules

42676

Bit 31 Bit 0

A communication fault sets all bits in the module-fault word.

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Common Module Features Chapter 3

Fault and Status Reporting between Output Modules and Controllers

ControlLogix digital output modules multicast fault and status data to any owner-controller or listening controller. Like input modules, output modules maintain a module-fault word, the highest level of fault reporting. However, some output modules use additional words to indicate fault conditions.

The table lists the fault words and the associated tags that can be examined in program logic to indicate when a fault has occurred for a standard output module.

All words are 32-bit, although only the number of bits appropriate for each module’s density are used. For example, the 1756-OB8 module has a modulefault word of 32 bits. But, because this is a eight-point module, only the first eight bits (0…7) are used in the module-fault word.

Fault bits in the fuse blown word and field power loss word are logically entered into the module-fault word. Depending on the module type, a bit set in the module-fault word can mean multiple things, as indicated in the following table.

Table 6 - Fault Words on Output Modules

Word Tag Name Description

Module-fault Fault Provides fault summary reporting. Available on all digital output

modules.

Fuse blown FuseBlown Indicates a point/group fuse blown on the module. Available only on

1756-OA16, 1756-OA8D, 1756-OA8E, 1756-OB16D, 1756-OB16E, 1756-OB16EIF, 1756-OB8EI, 1756-OV16E, and 1756-OV32E modules. For more information, see Electronic Fusing

on page 57.

Field power loss FieldPwrLoss Indicates a loss of field power to a point on the module. Available on

the 1756-OA8E module only. For more information, see Field Power

Loss Detection on page 60.

Table 7 - Bits Set in Module-fault Word

Condition Bits Set

Communication fault All 32 bits are set to 1, regardless of the module’s density.

Fuse bl own

Only the bit affected is set to 1.

Field power loss

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Chapter 3 Common Module Features

The following illustration offers an overview of the fault reporting process on ControlLogix digital output modules.

Module-fault Word

All modules

Fuse Blown Word

Point Level Group Level

1756-OA8D 1756-OA16 1756-OA8E 1756-OB16E 1756-OB8EI 1756-OV16E 1756-OB16D 1756-OV32E 1756-OB16IEF

Field Power Loss Word

1756-OA8E only

41457

Bit 31 Bit 0

A blown fuse for any point or group sets the bit for that point or group in the fuse blown word and also sets the appropriate bits in the module-fault word.

A communications fault sets all bits in the module-fault word. A fuse blown or field power loss condition sets the appropriate bits in the module-fault word.

A loss of field power from any group sets the bit for that point in the field power loss word and also sets the appropriate bits in the module-fault word.

Group 0

Group 1

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Chapter 4

Diagnostic Module Features

Diagnostic modules provide additional reporting information to the controller, such as a timestamp of the time a module fault occurs or clears, no load detection, and pulse tests. The table lists the available diagnostic digital I/O modules.

Diagnostic Input Module Compatibility

When designing systems with ControlLogix diagnostic input modules, consider these factors:

• Voltage necessary for your application

• Current leakage

• Whether you need a solid state device

• Whether your application should use sinking or sourcing wiring

Top ic P age

Diagnostic Input Module Compatibility 67

Diagnostic Output Module Compatibility 68

Diagnostic Features 68

Features Specific to Diagnostic Input Modules 71

Features Specific to Diagnostic Output Modules 75

Fault and Status Reporting between Input Modules and Controllers 79

Fault and Status Reporting between Output Modules and Controllers 81

Cat. No. Description

1756-IA8D 79…132V AC 8-point diagnostic input module

1756-IB16D 10…30V DC diagnostic input module

1756-OA8D 74…132V AC 8-point diagnostic output module

1756-OB16D 19.2…30V DC 16-point diagnostic output module

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Chapter 4 Diagnostic Module Features

Diagnostic Output Module Compatibility

ControlLogix diagnostic output modules are capable of directly driving the ControlLogix diagnostic digital inputs. When diagnostics are used, a shunt resistor is required for leakage current.

For more information on the compatibility of motor starters with ControlLogix output modules, see Appendix

Diagnostic Features

The table below lists features common to all ControlLogix diagnostic digital I/O modules.

Diagnostic I/O modules also have the common module features

described in Chapter 3

Diagnostic Latch of Information

Diagnostic latching allows diagnostic I/O modules to latch a fault in the set position once it has been triggered, even if the error condition causing the fault to occur disappears.

The Point column on the left side of the Configuration tab lets you set diagnostic latching to occur for a specific point where the field device is wired to the I/O module.

Follow these steps to enable or disable diagnostic latching.

1. On the Module Properties dialog box, click the Configuration tab.

Top ic Pag e

Diagnostic Latch of Information 68

Diagnostic Timestamp 69

8-Point AC/16-Point DC 70

Point-level Fault Reporting 70

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Diagnostic Module Features Chapter 4

2. Do one of the following in the Enable Diag. Latching column:

• To enable diagnostic latching for a specific point, check the

corresponding checkbox.

• To disable diagnostic latching for a specific point, clear the

corresponding checkbox.

3. Click OK.

Latched diagnostic features can be cleared by using these methods:

• Reset Diagnostic Latch service

• Software reset during online monitoring

• Cycling power to the module’s

Follow these steps to a reset a latched fault through RSLogix 5000 software during online monitoring.

1. On the Modules Properties screen, click the Diagnostics tab.

2. Click Reset next to the point for which to reset a latched fault.

3. Click OK.

Diagnostic Timestamp

Diagnostic I/O modules can timestamp the time when a fault occurs or when it clears. This feature provides greater accuracy and flexibility in running applications. Modules use the ControlLogix system clock from a local controller to generate timestamps.

To use diagnostic timestamps, you must choose the appropriate communication format during initial configuration. For more information, see To c on fi g ur e

features specific to fast modules, see Chapter 5. on page 134.

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Chapter 4 Diagnostic Module Features

8-Point AC/16-Point DC

Diagnostic I/O modules provide various grouping of points on different modules. The eight-point AC modules and 16-point DC modules provide additional flexibility when designing module applications. The greater number of points allows for more field devices to be attached to I/O modules to boost efficiency.

Point-level Fault Reporting

Diagnostic I/O modules set bits to indicate when a fault has occurred on a point-by-point basis. The following fault conditions generate their own unique fault bits.

Using these bits in tandem with data echo and manually performing a pulse test can help to further isolate the fault. Ta b l e 9

lists possible diagnostic faults on the

1756-OA8D module.

Table 8 - Unique Fault Bits for I/O Points

Input Points Output Points

These conditions can set a fault bit for an input point:

• Open wire

• Field power loss (1756-IA8D only)

These conditions can set a fault bit for an output point:

• Fuse b lown

• No load

• Output verify

• Field power loss (1756-IA8D only)

Table 9 - 1756-OA8D Point-level Fault Scenarios

Ladder commands output to be On Ladder commands output to be Off Possible cause of fault

1. Output Data Echo returns the state of the output as Off.

2. Fuse Blown bit is set.

1. Output Data Echo returns the state of the output as Off.

(4)

2. Pulse Test fails.

Output is shorted to L2.

1. Output Data Echo returns the state of the output as On.

2. Pulse Test fails.

(1)

1. Output Data Echo returns the state of the output as Off.

2. No Load bit is off.

No Load or output is shorted to L1.

1. Output Data Echo returns the state of the output as Off.

2. No Load shows a fault.

3. Field Power Loss shows a fault.

4. Pulse Test fails.

1. Output Data Echo returns the state of the output as Off.

2. No Load bit is set.

3. Field Power Loss is set.

4. Pulse Test fails.

L1 or L2 are disconnected or outside the 47-63 Hz frequency range.

1. Output Data Echo returns the state of the output as On.

(2)

2. Output Verify bit is set.

(3)

1. Data Echo returns the state of the output as Off.

2. Pulse Test fails.

Hardware point damage.

(5)

(1) When pulse test is executed, it is normal operation to see a momentary pulsation on the module display. (2) The output cannot turn On due to hardware point damage. (3) Depending on the characteristics of an applied short-circuit, an output verify fault could be set until the short- circuit is detected by the module and the output is turned Off. (4) It is not possible to create a fuse blown fault in the Off state. If a short-circuit occurs, the output point is turned Off and the fault appears in the Off state until the point is reset. (5) During normal operating conditions, hardware damage should not be possible. An output shorted to L2 may temporarily cause a hardware point fault. See output shorted to L2 as a possible cause.

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Diagnostic Module Features Chapter 4

The following table lists possible diagnostic faults on the 1756-OB16D module.

Features Specific to Diagnostic Input Modules

The table below lists features specific to ControlLogix diagnostic digital input modules.

Diagnostic Change of State for Input Modules

If the diagnostic change of state feature is enabled, a diagnostic input module sends new data to the owner-controller when one of the events described in the table occurs.

Table 10 - 1756-OB16D Point-level Fault Scenarios

Ladder commands output to be On Ladder commands output to be Off Possible cause of fault

1. Output Data Echo returns the state of the output as Off.

2. Fuse Blown bit is set.

(1)

1. Output Data Echo returns the state of the output as Off.

(4)

2. Pulse Test fails.

(5)

Output is shorted to GND.

1. Output Data Echo returns the state of the output as On.

2. Pulse Test fails

1. Output Data Echo returns the state of the output as Off.

2. No Load bit is set.

3. Pulse Test passes.

One of the following could be the cause.

1. No Load.

2. Output shorted to DC+.

3. No power at module.

1. Output Data Echo returns the state of the output as On.

(2)

2. Output Verify sets a bit.

(3)

1. Output Data Echo returns the state of the output as Off.

2. Pulse Test fails.

Hardware po int damage.

(6)

(1) The electronic protection of this module has been designed to provide protection for the module from short-circuit conditions. The protection is based on a thermal cutout principal. In the event of a

short-circuit condition on an output channel, that channel will limit the current within milliseconds after its thermal cutout temperature has been reached. Other channels could produce a false error on the output verify fault signal due to the supply dropping below the minimum detect level of 19.2V DC. The output channels that are affected by this phenomena will continue to operate as directed by the

module master (CPU, bridge, and so forth). What this means is that the output verify fault signals of the other channels should be checked and reset if a short-circuit on one channel occurs. (2) The output cannot turn On due to hardware point damage. (3) Depending on the characteristics of an applied short-circuit, an output verify fault could be set until the short- circuit is detected by the module and the output is turned Off. (4) It is not possible to create a fuse blown fault in the Off state. If a short-circuit occurs, the point is turned Off and the fault appears in the Off state until that point is reset. (5) When the pulse test is executed, it is normal operation to see a momentary pulsation on the module display. (6) During normal operating conditions, hardware damage should not be possible. An output shorted to GND may temporarily cause a hardware point fault. See output shorted to GND as a possible cause.

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Diagnostic Change of State for Input Modules 71

Open Wire Detection 73

Field Power Loss Detection 74

Event Description

RPI A user-defined rate at which the module updates the information sent to its

owner-controller. This is also known as Cyclic Data Transfer.

Change of State Configurable feature that, when enabled, instructs the module to update its

owner-controller with new data whenever a specified input point transitions from On to Off and Off to On. The data will be sent at the RPI rate where there is no change of state. By default, this setting is always enabled for input modules.

Diagnostic Change of State Information updates when any change in the diagnostics for an input module

occurs.

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Chapter 4 Diagnostic Module Features

Although the RPI occurs continuously, the COS feature lets you to decide whether changes in a module’s diagnostic detection should cause the module to send real-time data to the owner-controller.

1. On the Module Properties dialog box, click the Configuration tab.

2. Do the following in the Enable Change of State column:

• To enable the input module to send new data to the owner-controller at

the RPI, on input COS if it is enabled, and if a diagnostic fault occurs, check the corresponding Off

 On or On Off checkbox for a point.

• To disable the feature, clear the corresponding checkbox for a point.

Real-time data is not sent when a diagnostic fault occurs but is still sent at the specified RPI or on input COS if it is enabled.

3. Click OK.

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Diagnostic Module Features Chapter 4

Open Wire Detection

Open Wire is used to verify the field wiring is connected to the module. The field device must provide a minimum leakage current to function properly.

A leakage resistor must be placed across the contacts of an input device. The resulting current is then expected to exist when the input is open. For more information, see each module’s specifications in Chapter

When an Open Wire condition is detected, a point-level fault is sent to the controller to identify the exact point fault. This feature has a corresponding tag that can be examined in the user program in the event of a fault.

Follow these steps to configure open wire detection.

1. On the Module Properties dialog box, click the Configuration tab.

2. Do one of the following in the Open Wire (middle) column:

• To enable the open wire detection for a specific point, check the

corresponding checkbox.

• To disable open wire detection for a specific point, clear the corresponding checkbox.

3. Click OK.

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Chapter 4 Diagnostic Module Features

Field Power Loss Detection

For the standard digital output modules, the Field Power Loss detection feature is found on the 1756-IA8D module only. When field power to the module is lost, or zero cross cannot be detected, a point-level fault is sent to the controller to identify the exact point faulted.

This feature has a corresponding tag that can be examined in the user program in the event of a fault. For information on these tags, see Chapter A

Follow these steps to enable or disable diagnostics for field power loss.

1. On the Module Properties dialog box, click the Configuration tab.

2. Do one of the following in the Enable Diagnostics for Field Power Loss

column:

• To enable field power loss detection for a specific point, check the corresponding checkbox.

• To disable field loss detection for a specific point, clear the corresponding checkbox.

3. Click OK.

IMPORTANT

Only enable Field Power Loss detection for points that are in use. If this feature is enabled for points that are not in use, you will receive faults for those points during operation.

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Diagnostic Module Features Chapter 4

Features Specific to Diagnostic Output Modules

The table below lists features specific to ControlLogix diagnostic digital output modules.

Field Wiring Options

As with diagnostic input modules, ControlLogix diagnostic output modules provide isolated or nonisolated wiring options. I/O modules provide point-topoint, group-to-group, or channel-to-channel wiring isolation.

Your specific application determines what type of isolation is necessary and which output module to use.

No Load Detection

For each output point, no load detection senses the absence of field wiring or a missing load from each output point in the Off state only.

The output circuit on a diagnostic output module has a current sensing optoisolator used in parallel with the output transistor. Current flows through this sensing circuit only when the output is Off, as shown in the simplified diagram.

Top ic Pag e

Field Wiring Options 75

No Load Detection 75

Field-side Output Verification 76

Pulse Test 78

Diagnostic Change of State for Output Modules 79

IMPORTANT

Although some ControlLogix diagnostic I/O modules provide nonisolated, field-side wiring options, each I/O module maintains internal electrical isolation between the system side and field side.

Current Sense

Load

V+

41681

Output Tra ns is to r

Current Flow with Output Off

Current Flow with

Output On

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Chapter 4 Diagnostic Module Features

Diagnostic output modules list a minimum load current specification (1756-OA8D = 10 mA & 1756-OB16D = 3 mA). In the On state, the module must be connected to a load that will draw a minimum current equal to these values.

If a connected load is sized in accordance with the minimum load current specification, diagnostic output modules are capable of sensing current through the optoisolator and the load when the output point is Off.

Follow these steps to enable no load detection.

1. On the Module Properties dialog box, click the Configuration tab.

2. Do one of the following in the No Load column:

• To enable the feature for a specific point, check the corresponding

checkbox.

• To disable the feature for a specific point, clear the corresponding checkbox.

3. Click OK.

This feature has a corresponding tag that can be examined in the user program in the event of a fault. For more information on these tags, see Appendix

Field-side Output Verification

Field-side output verification informs you that logic-side instructions consumed by the module are accurately represented on the power side of a switching device. For each output point, this feature confirms that the output is On when it is commanded to be On.

The diagnostic output module can tell a controller that it received a command and whether the field-side device connected to the module has executed the command. For example, in applications that need to verify that the module has accurately followed the processor’s instructions, the module samples the field-side state and compares it to the system-side state.

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Diagnostic Module Features Chapter 4

This feature has a corresponding tag that can be examined in the user program in the event of a fault. For more information on these tags, see Appendix

If an output cannot be verified, a point-level fault is sent to the controller.

Follow these steps to enable the field-side output verification.

1. On the Module Properties dialog box, click the Configuration tab.

2. Do one of the following in the Output Verify column:

• To enable the feature for a specific point, check the corresponding

checkbox.

• To disable the feature for a specific point, clear the corresponding checkbox.

3. Click OK.

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Chapter 4 Diagnostic Module Features

Pulse Test

Pulse test is a feature found on diagnostic output modules that can verify outputcircuit functionality without actually changing the state of the output load device. A short pulse is sent to the targeted output circuit. The circuit should respond as it would if a real change-of-state command was issued, but the load device does not transition.

See page 227

in Appendix C for instructions on performing a pulse test with a

CIP Generic Message instruction.

The table explains how a pulse test can be used to perform a preemptive diagnosis of possible future module conditions.

TIP

Consider the following when using the pulse test:

• Only use the test when the output state does not transition for long periods of time. Normal diagnostics will catch faults if the outputs are transitioning regular ly.

• When first performing the pulse test, verify that the load will not transition. You should be at the actual load while the test is performed.

Objective Pulse Test Description

Detect a blown fuse before it happens

The Blown Fuse diagnostic can be used only when an output module is in the On state. However, you can use a pulse test when an output module is in an Off state to determine whether operating conditions may cause a blown fuse.

When you perform a pulse test on a module in the Off state, the output point is commanded to be On briefly. Although no diagnostic bits are set in the output data echo, the pulse test reports a failure if the conditions when the point is On indicate a blown fuse may occur. See Point-level Fault Reporting

on page 70.

IMPORTANT

The pulse test does not guarantee a fuse will blow when the output point turns On. It merely indicates a blown fuse is possible.

Detect a No Load condition with an output On

No Load detection can only detect a fault when an output point is in the Off state. However, you can use a pulse test when an output module is in an On state to determine whether operating conditions for a point may cause a No Load condition.

If you perform a pulse test on an output point while it is in the On state, the output point is commanded to be Off briefly. The pulse test reports a fail ure because conditions when the point is Off indicate t he possible absence of a field device; in this case, though, the No Load bit will not be set. See Point-level Fault Reporting

page 70.

IMPORTANT

The Pulse Test does not guarantee the absence of a load. It merely indicates a No Load condition is possible.

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Diagnostic Module Features Chapter 4

Diagnostic Change of State for Output Modules

If the Diagnostic Change of State feature is enabled, a diagnostic output module sends new data to the owner-controller when one of the events described in the table occurs.

Unlike diagnostic input modules, this feature cannot be disabled for diagnostic output modules. There is no Enable Change of State for Diagnostic Transitions checkbox on the Configuration tab to check or clear for diagnostic output modules.

Fault and Status Reporting between Input Modules and Controllers

ControlLogix diagnostic digital input modules multicast fault and status data to any owner-controller or listening controller. All diagnostic input modules maintain a module-fault word, the highest level of fault reporting. Some modules use additional words to indicate fault conditions.

The following table lists the fault words and the associated tags that can be examined in program logic to indicate when a fault has occurred for a diagnostic input module.

All words are 32-bit, although only the number of bits appropriate for each module’s density are used. For example, the 1756-IA16I module has a modulefault word of 32 bits. But, because this is a 16-point module, only the first 16 bits (0…15) are used in the module-fault word.

Table 11 - Diagnostic Change of State Events

Event Description

Receipt of output data Output module sends data when it echoes back to the owner-controller.

Diagnostic change of state O utput module sends data when any change in the diagnostics output point

occurs.

Table 12 - Fault Words on Diagnostic Input Modules

Word Tag Name Description

Module-fault Fault Provides fault summary reporting. Available on all digital input

modules.

Field Power Loss FieldPwrLoss Indicates loss of field power to a group on the module. Available on

the 1756-IA8D only. For more information, see Field Power Loss Detection

on page 74.

Open Wire OpenWire Indicates the loss of a wire from a point on the module. For more

information, see Open Wire Detection

on page 73.

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Chapter 4 Diagnostic Module Features

Fault bits in the field-power loss word and open wire word are logically entered into the module-fault word. Depending on the module type, a bit set in the module-fault word can mean multiple things, as indicated in the table.

The following illustration provides an overview of the fault reporting process for digital input modules.

Table 13 - Bits Set in Module-fault Word

Condition Bits Set

Communications fault All 32 bits are set to 1, regardless of the module’s density.

Field-power loss

Only the bit affected is set to 1.

Open wire

Module-fault Word

All modules

Field Power Loss Word

1756-IA8D only

Open Wire Word

Bit 31 Bit 0

An open wire condition on any point sets the bit for that point in the open wire word and also sets the appropriate bit in the module-fault word.

A loss of field power sets the bit for that group in the field-power loss word and also sets the appropriate bit in the module-fault word.

A communications fault sets all bits in the module-fault word. A field-power loss or open wire condition sets the appropriate bit in the module -fault word.

Group 0

Group 1

41456

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Diagnostic Module Features Chapter 4

Fault and Status Reporting between Output Modules and Controllers

ControlLogix diagnostic digital output modules multicast fault and status data to any owner-controller or listening controller. Like input modules, output modules maintain a module-fault word, the highest level of fault reporting. However, some output modules use additional words to indicate fault conditions.

The table lists the fault words and the associated tags that can be examined in program logic to indicate when a fault has occurred for a diagnostic output module.

All words are 32-bit, although only the number of bits appropriate for each module’s density are used. For example, the 1756-OB8 module has a modulefault word of 32 bits. But, because the module is an 8-point module, only the first 8 bits (0…7) are used in the module-fault word.

Fault bits in the fuse blown word, field-power loss word, no load word and output verify word are logically entered into the module-fault word. Depending on the module type, a bit set in the module-fault word can mean multiple things, as indicated in the table.

Table 14 - Fault Words on Diagnostic Output Modules

Word Tag Name Description

Module-fault Fault Provides fault summary reporting. Available on all digital output

modules.

Fuse Blown FuseBlown Indicates a blown fuse for a point on the module. For more information,

see For more information, see Electronic Fusing

on page 57.

No Load NoLoad Indicates a loss of a load from a point on the module. For more

information, see No Load Detection

on page 75.

Output Verify OutputVerify Indicates when an output is not performing as commanded by the

owner- controller. For more in formation, see Field-side Output

Verification on page 76.

Table 15 - Bits Set in Module-fault Word

Condition Bits Set

Communication fault All 32 bits are set to 1, regardless of the module’s density.

Fuse bl own

Only the bit affected is set to 1.

Field-power loss

No load

Output verify

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Chapter 4 Diagnostic Module Features

The following illustration provides an overview of the fault reporting process for digital output modules.

Module-fault Word

Fuse Blown Wor d

Field-power Loss Word

1756-OA8D only

Bit 31 Bit 0

A no load condition for any point sets the bit for that point in the no load word and also sets the appropriate bit in the module-fault word.

A blown fuse for any point sets the bit for that point in the fuse blown word and also sets the appropriate bits in the module-fault word.

A communications fault sets all bits in the module-fault word. A fuse blown, field-power loss, no load or output verify condition sets the appropriate bit in the module-fault word.

No Load Word

Output Verify Word

A loss of field power from any group sets the bit for that point in the field-power loss word and also sets the appropriate bits in the module-fault word.

An output verify condition for any point sets the bit for that point in the output verify word and also sets the appropriate bit in the module-fault word.

Group 0

Group 1

41457

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Chapter 5

Fast Module Features

Fast digital I/O modules provide quick response time for high-speed control applications. The table lists the available fast digital I/O modules.

Fast Input Module Compatibility

When designing systems with ControlLogix fast input modules, consider these factors:

• Voltage necessary for your application

• Sensor performance and specifications

• Whether your application should use sinking or sourcing wiring

Top ic Pag e

Fast Input Module Compatibility 83

Fast Output Module Compatibility 84

Fast Feat ures 84

Features Specific to Fast Input Modules 85

Features Specific to Fast Output Modules 95

Fault and Status Reporting between Input Modules and Controllers 106

Fault and Status Reporting between Output Modules and Controllers 107

Cat. No. Description

1756-IB16IF 10…30V DC,16-point, isolated, fast peer control input module

1756-OB16IEF 10…30V DC,16-point, isolated, fast peer control output module

1756-OB16IEFS 10…30V DC, 16-point, isolated, fast, scheduled per point output module

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Chapter 5 Fast Module Features

Fast Output Module Compatibility

ControlLogix fast output modules can be used to drive a variety of output devices. Typical output devices compatible with ControlLogix outputs include these items:

• Solenoids

• Indicators

Follow these guidelines when designing a system:

• Make sure that the ControlLogix outputs can supply the necessary surge and continuous current for proper operation.

• Make sure that the surge and continuous current are not exceeded. Damage to the module could result.

When sizing output loads, refer to the documentation supplied with the output device for the surge and continuous current needed to operate the device.

Outputs on fast output modules can be directly wired to inputs on fast input modules.

Fast Features

Module features include all the common features described in Chapter 3, as well the extended capabilities described within this chapter.

For higher-speed control, the 1756-OB16IEF output module can be configured to receive input status over the backplane directly from the 1756-IB16IF input module or 1756-LSC8XIB8I counter module without controller processing. This feature, know as peer ownership, is described in the ControlLogix Peer Ownership Application Technique, publication 1756-AT016

IMPORTANT

To configure the modules, you must have the following:

• The 1756-OB16IEF module requires RSLogix 5000 software, version

18.02.00 or later or Studio 5000 environment, version 21.00.00 or later.

• The 1756-OB16IEFS module requires Studio 5000 environment, version

21.00.00 or later.

• The Add-on Profile (AOP) for each module available for download at

http://support.rockwellautomation.com/controlflash/LogixProfiler.asp

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Fast Modu le Fea tures Chapter 5

Response Time

The tables below indicate the screw-to-backplane response time of fast input and fast output modules.

Features Specific to Fast Input Modules

The table below lists features specific to ControlLogix fast digital input modules.

Table 16 - Input Response Time

Delay Respons e Time

Total On/Off delay (screw to backplane) 14 s nom/23 s max + user-configurable filter time

Hardware delay < 1 µs nom, 2 µs max

Firmware delay 13 µs nom, 21 µs max

User-configurable filter time 0…30,000 µs

Table 17 - Output Response Time

Delay Respons e Time

Total On/Off delay (screw to backplane) 14 s nom/23 s max

Hardware delay < 1 µs nom, 2 µs max

Firmware delay 13 µs nom, 21 µs max

Top ic Page

Pulse Capt ure 86

Per Point Timestamping and Change of State 87

Software Configurable Filter Times 90

Dedicated Connection for Event Tasks 93

IMPORTANT

In RSLogix 5000 software, version 18.02.00 and 19.01.00, output tag information is sent to the 1756-IB16IF module only at the RPI rate defined during configuration. For optimal performance, use an Immediate Output (IOT) instruction.

For example, the rung shown below contains an IOT instruction for a fast input module in slot 3. Add a similar rung to your last routine within the Main Task to mimic normal output tag processing.

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Chapter 5 Fast Module Features

Pulse Capture

The 1756-IB16IF fast input module can be used to detect or latch short duration pulses. The module can detect incoming pulses with a duration as short as 10 µs if the frequency is under 4 kHz (period of 250 µs).

When the module detects a short duration pulse at an input point, it sets the corresponding bit for the Pt[x].NewDataOffOn or Pt[x].NewDataOnOff input tag. This bit remains latched until acknowledged. As a result, you can use this bit to detect a transition that is too fast to be detected by the program scan. You can also determine how rapid the transition was by configuring the module to latch timestamps for the point, as described in Per Point Timestamping and Change of

State on page 87.

To acknowledge the last captured pulse and reset the pulse latch, you set the rising edge of the corresponding bit in these output tags:

• Pt[x].NewDataOffOnAck—Acknowledges that the input point has transitioned to an On state and resets the pulse latch.

• Pt[x].NewDataOnOffAck—Acknowledges that the input point has transitioned to an Off state and resets the pulse latch.

You can change output tag values in program logic while normal module operation continues or through the RSLogix 5000 tag editor. For more information about module tags, refer to Appendix

Once a pulse latch is reset for an input point, the next pulse at that point sets the corresponding bit in the Pt[x].NewDataOffOn or Pt[x].NewDataOnOff input tags.

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Fast Modu le Fea tures Chapter 5

Per Point Timestamping and Change of State

With per point timestamping, each input point on the module records timestamps in CIP Sync format at these speeds:

• ± 4 µs for inputs < 4 kHz

• ± 13 µs for inputs > 4 kHz

You can configure an input point to record a timestamp when the point transitions from On to Off, Off to On, or in both directions. By default, all points are configured to record a timestamp in both directions.

You can also configure the module to latch timestamps for an input point’s last transition. When latching is enabled for a specific point, the point records a timestamp in the Pt[x].Timestamp.OffOn or Pt[x].Timestamp.OnOff input tags. The timestamp remains latched, and no new timestamps are recorded for the input point until the timestamp is acknowledged and reset. As a result, you can use the timestamp to determine the speed of a transition that is too fast to be detected by the program scan.

To acknowledge a transition and reset a timestamp latch, you set the corresponding bit in these output tags:

• Pt[x].NewDataOffOnAck—Acknowledges that the input point has transitioned to an On state and resets the timestamp latch.

• Pt[x].NewDataOnOffAck—Acknowledges that the input point has transitioned to an Off state and resets the timestamp latch.

The Pt[x].TimestampDropped input tag indicates whether a new timestamp has not been recorded because a previous timestamp was either latched or unacknowledged.

Once a timestamp latch is reset for an input point, a new timestamp may be recorded in the Pt[x].Timestamp.OffOn or Pt[x].Timestamp.OnOff input tags upon the next transition.

You can configure per point timestamping in three ways:

• Timestamping enabled without latching (default configuration)

• Timestamping enabled with latching

• Timestamping disabled

IMPORTANT

Timestamping functions only in a CIP Sync system. If you are using change of state (COS) in a system using Coordinated System Time (CST), all timestamp values and the GrandMasterClockID input tag are set to zero.

To set up CIP Sync time synchronization on the local controller, use the Date/Time tab in the controller properties. For more information about CIP Sync configuration, refer to the Integrated Architecture and CIP Sync

Configuration Application Technique, publication IA-AT003

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Chapter 5 Fast Module Features

Follow these steps to configure per point timestamping and enable COS.

1. On the New Module dialog box, click Change to display the Module Definition dialog box.

2. Use the table below to choose a connection format and input data type from the Connection and Input Data pull-down menus.

IMPORTANT

To enable timestamping, choose Timestamp Data as the input data type.

Connection Format Input Data Data Return

Data Timestamp Data Module returns input data with COS timestamps in CIP Sync system

time.

Data Module returns input data without COS timestamps. This format is

useful when the highest possible throughp ut is required, and timestamps are not required.

Data with Event Timestamp Data Results in two input connections:

• Connection to return input data with COS timestamps in CIP Sync system time.

• Connection to initiate event tasks. See page 93

Listen Only Timestamp Data These formats have the same definition as those above except that

they are Listen-only connections.

Data

Listen Only with Event Timestamp Data

TIP

You can change the connection format at any time after creating a new module except when you are online. The AOP will apply all the configuration data and create the tags required for the new connection format.

Opens the Module Definition dialog box.

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Fast Modu le Fea tures Chapter 5

3. On the New Module or Module Properties dialog box, click the Configuration tab.

Timestamp fields only appear on the Configuration tab when you choose Timestamp Data from the Input Data pull-down menu on the Module Definition dialog box.

4. Complete the fields as described in the table below and click OK.

5. If you checked the Latch Timestamps checkbox, use program logic or the

RSLogix 5000 tag editor to acknowledge transitions and clear latched timestamps via the Pt[x].NewDataOffOnAck and Pt[x].NewDataOnOffAck output tags.

For more information about module tags, refer to Appendix

Field Description Configuration Tag

Enable COS/Timestamps Off

 On

To enable COS and timestamping for an Off to On transition for a point, check the corresponding checkbox.

To disable COS and timestamping for an Off to On transition for a point, clear the corresponding checkbox.

Pt[x].COSOffOnEn

Enable COS/Timestamps On

 Off

To enable COS and timestamping for an On to Off transition for a point, check the corresponding checkbox.

To disable COS and timestamping for an On to Off transition for a point, clear the corresponding checkbox.

Pt[x].COSOnOffEn

Latch Timestamps Check the checkbox to latch a CIP Sync timestamp for a COS

transition:

• When an initial timestamp is latched, timestamps fo r subsequent COS transitions are dropped.

• Once a latched timestamp is acknowledged via the corresponding bit in the Pt[x].NewDataOffOnAck or Pt[x].NewDataOnOffAck tag, the timestamp is overridden upon the next COS transition.

IMPORTANT: Timestamps are latched only for points that are enabled for COS and timestamping.

LatchTimestamps

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Software Configurable Filter Times

To account for hard contact bounce, you can configure Off to On and On to Off input filter times of 0…30, 000 µs in RSLogix 5000 software. These filters define how long an input transition must remain in the new state before the module considers the transition valid.

When an input transition occurs, the module timestamps the transition on the edge of the transition and stores timestamp data for the transition. The module then monitors the input for the duration of the filter time to verify that the input remains in the new state:

• If the input remains in the new state for a time period equal to the filter time, the input is recognized and recorded. The module sends timestamp data for the transition and the input’s On/Off state to the controller.

• If the input changes state again before the duration of the filter time has elapsed, the module continues to scan that input for up to 10x

the filter

time. During this continued scan period, one of the following events occurs:

– In the time period that is 10x the duration of the filter time, the input

returns to the transitioned state for the duration of the filter time. In this case, the module sends timestamp data from the initial transition to the controller.

– In the time period that is 10x the duration of the filter time, the input

never remains in the transitioned state for the duration of the filter time. In this case, the input is recognized, but the module does not consider the original transition valid and drops the timestamp.

EXAMPLE

A 1756-IB16IF module is configured for a 2 ms filter time for Off to On transitions. In this example, three possible scenarios can result after an input transitions from Off to On:

•Scenario 1—The input turns On and remains On for the full 2 ms filter time. The module considers the transition valid and sends the data recorded at the transition to the controller (Figure 9 on page 91

•Scenario 2—The input turns On but turns Off before the 2 ms filter time elapses. The module continues to monitor the input for 10x the duration of the filter time. Within that time period, the input turns On again and remains On for at least 2 ms. The module considers the transition valid and sends the data timestamped at the original transition to the controller (Figure 10 on page 91

•Scenario 3—The input turns On but turns Off before the 2 ms filter time elapses. The module continues to monitor the input for 10x the duration of the filter time. Within that time period, the input never remains On for at least 2 ms. The module considers the transition invalid and drops the data timestamped at the original transition (Figure 11 on page 91

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Figure 9 - Valid Transition with No Bounce

Figure 10 - Transition Valid with Bounce

Figure 11 - Invalid Transition

012345678

Input turns On, and a

timestamp is recorded.

Time in milliseconds

Input remains On for at least 2 ms. The transition is considered valid, and the timestamp is sent to the controller.

012345678

Time in milliseconds

Input turns On and remains On for at least 2 ms in the 20 ms time period that is 10x the input filter time. The module sends the timestamp recorded at the original transition point (time 0) to the controller.

Input turns Off before 2 ms elapses.

Input turns On, and a

timestamp is recorded.

012341718 19 20

Time in m illiseconds

Input turns Off before 2 ms elapses.

The input never remains On for at least 2 ms.

After the 20 ms time period that is 10x the input filter time, the module drops the data recorded at the original transition. If an RPI occurs during this time, the module sends the controller its current valid input data. The data that is sent does not include data from the transition because the input transition has not cleared the filter and been recognized as a valid input.

Input turns On, and a

timestamp is recorded.

The next time the input turns On, the module records the transition as timestamp 21.6 once the input passes the filter time.

…

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Follow these steps to configure input filter times.

1. On the Module Properties dialog box, click the Configuration tab.

2. In the Input Filter Time column, enter Off to On and On to Off input

filter times from 0…30,000 µs and click OK.

3. Complete the fields as described in the table below and click OK.

Field Description Configuration Tag

Enable Filter To enable filtering for a point, check the corresponding checkbox.

To disable filtering for a point, clear the corresponding checkbox.

Pt[x].FilterEn

Input Filter Time Off

 On

Enter an Off to On input filter time from 0…30,000 µs. FilterOffOn

Input Filter Time On

 Off

Enter an On to Off input filter time from 0…30,000 µs. FilterOnOff

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Dedicated Connection for Event Tasks

The 1756-IB16IF input module can initiate an event task over a dedicated second connection in response to four user-defined input patterns. You can define these patterns in real time during a control process by using these output tags:

• Event[x].Mask—Defines which input points trigger the event task.

• Event[x].Value—Defines whether the masked input points must be in the

On or Off state before the event task is triggered.

Each pattern can use any of the module’s 16 input points, as shown in the examples below.

In example pattern 1, the input module triggers the event task when input points 0…7 are in the On state.

In example pattern 2, the input module triggers the event task when input points 0…7 are in the Off state.

In example pattern 3, the input module triggers the event task when input points 4, 6, 8, and 10 are in the On state.

Table 18 - Example Pattern 1

Output Tag Bit Position

0123456789101112131415

Event[x].Mask 1111111100000000

Event[x].Value 11111111xxx xxxxx

Table 19 - Example Pattern 2

Output Tag Bit Position

0123456789101112131415

Event[x].Mask 1111111100000000

Event[x].Value 00000000xx xx xxxx

Table 20 - Example Pattern 3

Output Tag Bit Position

0123456789101112131415

Event[x].Mask 0000101010100000

Event[x].Value xxxx1x1x1x1xxxxx

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In example pattern 4, the input module triggers the event task when input points 0…3 are in the On state, and input points 12…15 are in the Off state.

Once you define a pattern, you can disable an event from being triggered without clearing its output data by using the Event[x].Disarm output tag.

You can change output tag values in program logic while normal module operation continues or through the RSLogix 5000 tag editor. For more information about module tags, refer to Appendix

To use a dedicated connection to trigger event tasks, you must set the module’s connection format to Data with Event, as shown in Figure 12

. For more information about connection formats, see Communication or Connection

Formats on page 131.

Figure 12 - Event Connection Format

When you choose the Data with Event connection format, the following occurs:

• A second connection dedicated to event data only is established with the module. This dedicated event connection reduces controller overhead when using inputs or input patterns to trigger event tasks in the controller.

• A new set of event tags is created, as described in Table 46 on page 193

Table 21 - Example Pattern 4

Output Tag Bit Position

0123456789101112131415

Event[x].Mask 1111000000001111

Event[x].Value 1111xxxxxx xx0000

IMPORTANT

All event masks and event values must be defined in the module’s output tags.

TIP

You can change the connection format at any time after creating a new module except when you are online. The AOP will apply all the configuration data required for the new connection format.

Choose Data with Event from the

Connection pull-down menu.

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Features Specific to Fast Output Modules

The table below lists features specific to ControlLogix fast digital output modules.

Programmable Fault State Delays

You can define the following states for an output point that is in Fault mode due to a communication failure:

• Duration—Defines the length of time that the output remains in the Fault mode state before transitioning to a final state of On or Off. By default, the output remains in the Fault mode state as long as the fault condition persists.

• Final state—Defines whether the output transitions to the On or Off state after the duration of the Fault mode state elapses. By default, the output transitions to the Off state.

Top ic Pa ge

Programmable Fault State Delays 95

Pulse Width Modulation 97

Peer I/O Control (1756-OB16IEF only) See the Peer I/O Control Application Technique,

publication 1756-AT016

IMPORTANT

In RSLogix 5000 software, version 18.02.00 and 19.01.00, output tag information is sent to the 1756-OB16IEF module only at the RPI rate defined during configuration. For optimal performance, use an Immediate Output (IOT) instruction.

For example, the rung shown below contains an IOT instruction for a fast output module in slot 3. Add a similar rung to your last routine within the Main Task to mimic normal output tag processing.

EXAMPLE

You define a duratio n of 1 sec ond and a final s tate of O n for an o utput po int. If a fault occurs at that point, the output remains in its Fault mode state (O ff, On, or Hold) for 1 second before transitioning to the On state.

IMPORTANT

If a connection is reestablished after an output point goes into Fault mode but before the duration time elapses, the settings you specify for the duration and final state no longer apply. For example, if you specify a 10 second duration and a final state of Off, and the fault ends in 3 seconds, the output point never transitions to the final state of Off.

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For more information about defining a Fault mode state, refer to Configurable

Point-level Output States on page 55.

Follow these steps to configure a fault state delay.

1. On the Module Properties dialog box, click the Output State tab.

2. Complete the fields as described in the table below and click OK.

Field Description 1756-OB16IEF

Configuration Tag

1756-OB16IEFS Configuration Tag

Fault Mode Output State Duration

Choose the length of time you want the output to remain in Fault mode state before transitioning to the final state:

• 1 second

• 2 seconds

• 5 seconds

• 10 seconds

• Forever (de fault) IMPORTANT: If you choose Forever, the output will remain in the Fa ult mode

state until a connection is reestablished. For example, if the Fault mode is Hold, and you specify a duration of Forever, then the output retains its Hold state and does not transition to a Final state if a fault occurs.

Pt[x].FaultValueStateDuration FaultValueStateDuration

Fault Mode Output State Final State

Choose whether you want the module to transition to an On or Off state after the Fault mode duration time elapses.

The default final state is Off. If you chose Forever, you cannot choose a final state. The module will retain its current Fault mode state.

Pt[x].FaultFinalState FaultFinalState

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Pulse Width Modulation

Pulse Width Modulation (PWM) provides precise, onboard control of an output’s pulse train with no program variability. To configure a PWM signal, you define two real-time values for the pulse train in the module’s output tags:

• Cycle time—The duration of a pulse cycle in seconds from 1 ms…1 hour.

• On time—The pulse width, or length of time that a pulse is active within a

cycle from 200 µs…1 hour. You can define the On time in seconds or as 0…100 percent of the cycle time. You may want to use a steady-state On time, such as for gluing applications, or a dynamic On time that is defined by program logic.

If the cycle time or On time is outside the valid range for an output, the corresponding bit in the Fault input tag is set and the module responds as described below.

If the cycle time or On time value changes while the output is generating a PWM signal, the changes are not applied until the next cycle of the PWM output. For instance, if the cycle time is erroneously set to an hour, a new cycle time will not go into effect until the last cycle of the hour is complete. To trigger the PWM output to restart immediately with a new cycle time or On time, turn the output Off and then back On.

Condition Result

PWMCycleTime <

minimum of 1ms PWMCycleTime = 1 ms

PWMCycleTime > maximum of 1 hour PWMCycleTime = 1 hour

PWMCycleTime

≤ PWMOnTime Output is always On

PWMOnTime < minimum of 200 µs Out put is always Off

PWMOnTime > maximum of 1 hour PWMOnTime = 1 hour

EXAMPLE

If PWMOnTime is 0.1 second and PWMCycleTime is 1.0 second and the PWMCycleTime is changed to 0.5 second just after the output turns On, the output will stay on for 0.1 second and then turn Off for 0.9 second to complete the cycle before the new 0.5 second cycle begins.

IMPORTANT

Before PWM will function, you must enable PWM during configuration and define the PWM cycle time and On time in the PWMCycleTime and PWMOnTime output tags.

If PWM is enabled (PWMEnable = 1) and the output is instructed to turn On (Data = 1), the output generates a PWM signal.

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Figure 13 compares two applications in which the output is instructed to turn

On for 4.5 seconds:

• In the application without PWM, a single pulse is generated. The pulse remains active for the same length of time the Data output tag is On (4.5 seconds).

• In the application with PWM, a series of pulses are generated. Each pulse is active for a configured On time of .5 seconds or 50% of the 1 second cycle time. The Data output tag is On for 4.5 seconds.

Figure 13 - PWM

By default, PWM is configured to continue the output pulse train until the output logic turns Off. When the output logic turns Off, the output pulse train immediately stops.

Figure 14 - PWM with Truncated Pulse

Output Logic

Output State

Output logic is On for 4.5 seconds.

Output is active for 4.5 seconds.

Output Logic

Output State

Output logic is On for 4.5 seconds.

Each pulse is active for 0.5 seconds (On time)

Application without PWM

Application with PWM

1 Second Cycl e Time

EXAMPLE

In Figure 14, the output logic is On for 4.25 seconds and then turns Off in the middle of the last pulse. Even though the PWM On time is configured for 0.5 seconds, the last pulse is only active for 0.25 seconds because it is truncated when the output logic turns Off.

Output Logic

Output State

Output logic is On for 4.25 seconds.

The last pulse is truncated when the output logic turns Off.

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You can modify the default PWM configuration for each of a module’s 16 outputs for further control of an output’s pulse train, as described in PWM

Configuration on page 103. Configuration options include the following:

• Cycle Limit and Execute All Cycles, as described below

• Minimum On Time, Extend Cycle, and Stagger Output as described on

page 100

Cycle Limit and Execute All Cycles

You can limit the number of pulse cycles that occur while an output is On. This feature is useful when you want to apply a level of output control when a process is stopped. For example, in a gluing application, you may want to apply 4 drops of glue to a product when the product is within a fixed window on a conveyor belt. By configuring a cycle limit of 4, you can make sure that only 4 drops of glue are applied even if the conveyor belt stops with the product in the window. Controlling the process with the Cycle Limit feature eliminates the need to write complex logic to detect a stopped conveyor belt.

Figure 15

shows a PWM pulse train configured with a cycle limit of 2. The PWMCycleLimitDone input tag indicates when the PWM cycle limit has been reached. The corresponding bit is reset upon the next rising edge of the output which restarts PWM.

Figure 15 - PWM Cycle Limit

IMPORTANT

The Program and Fault mode states configured for the module override the PWM output state unless the point is configured to hold the last state while in Program or Fault mode. If a point is configured to hold the last state and the output is currently On, the output will continue to use PWM until the PWM cycle limit is reached, the module transitions out of Program or Fault mode, or a final fault state goes into effect.

For more information, see the following:

• Configurable Point-level Output States

on page 55

• Programmable Fault State Delays on page 95

• Cycle Limit and Execute All Cycles on page 99

Output Logic

Only 2 cycles are executed even though the output logic remains On.

Output State

The cycle limit restarts when the output begins pulsing on the next rising edge of output logic.

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If the output logic turns Off before the cycle limit is reached, you can configure the pulse cycles to continue until the cycle limit is reached by enabling the Execute All Cycles option. Figure 16

shows a cycle limit of 2

with the Execute All Cycles option enabled.

Figure 16 - PWM Cycle Limit with Execute All Cycles Option

Minimum On Time, Extend Cycle, and Stagger Output

The Minimum On Time, Extend Cycle, and Stagger Output configuration options are useful in time-proportional control applications, such as temperature control. In these applications, PID calculations compare the actual temperature to the desired setpoint and vary the PWM On time to a heating element in real time to regulate temperature as it approaches the setpoint, as shown in Figure 17

Figure 17 - PWM for Time Proportioned Control

Output Logic

Both cycles are executed even though the output logic turned Off before the cycle limit was reached.

Output State

Heated Vessel

Variable PWM On Time from PID Calculation

Temperature Feedback to Analog Input

Allen-Bradley 1756-IA16I, 1756-IB16, 1756-IB16IF, 1756-IB16I, 1756-IA32 User Manual

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