Rockwell Automation Allen-Bradley ControlLogix 1756-IB16ISOE User manual

ControlLogix
Sequence of Events
Module
1756-IB16ISOE (24/48V dc),
1756-IH16ISOE (125V dc)
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.ab.com/manuals/gi) describes some important differences
between solid state equipment and hard-wired electromechanical devices.
Because of this difference, and also because of the wide variety of uses for
solid state equipment, all persons responsible for applying this equipment
must satisfy themselves that each intended application of this equipment is
acceptable.
In no event will Rockwell Automation, Inc. be responsible or liable for
indirect or consequential damages resulting from the use or application of
this equipment.
The examples and diagrams in this manual are included solely for illustrative
purposes. Because of the many variables and requirements associated with
any particular installation, Rockwell Automation, Inc. cannot assume
responsibility or liability for actual use based on the examples and diagrams.
No patent liability is assumed by Rockwell Automation, Inc. with respect to
use of information, circuits, equipment, or software described in this manual.
Reproduction of the contents of this manual, in whole or in part, without
written permission of Rockwell Automation, Inc. is prohibited.
Throughout this manual we may use notes to make you aware of
safety considerations.
WARNING Identifies information about practices or circumstances
that can cause an explosion in a hazardous environment,
which may lead to personal injury or death, property
damage, or economic loss.
IMPORTANT Identifies information that is critical for successful
application and understanding of the product.
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
•recognize the consequence
SHOCK HAZARD Labels may be located on or inside equipment to alert
people that dangerous voltage may be present.
BURN HAZARD Labels may be located on or inside equipment to alert
people that surfaces may be dangerous temperatures.

1Publication 1756-UM528A-EN-P - April 2004
Preface
Purpose of This Manual
This manual describes how to use the ControlLogix Sequence of
Events module in your ControlLogix application. With this manual,
you can learn how to install, configure and troubleshoot the module.
There are two types of ControlLogix Sequence of Events modules, as
described in Table Preface.1:
Who Should Use
This Manual
This manual is intended for individuals who program ControlLogix
control systems, such as:
•software engineers
•control engineers
•application engineers
To most efficiently use the Sequence of Events module, you should be
familiar with:
•ControlLogix™ controllers
•ControlLogix ControlNet™ communication modules
•RSLogix 5000™
•RSNetWorx for ControlNet™
Table Preface.1
Catalog number: Description: Availability date:
1756-IB16ISOE 16-point, 10 - 50V dc module June 2004
1756-IH16ISOE 16-point, 90 - 140V dc
module
April 2004
IMPORTANT The two types of Sequence of Events modules have
identical functionality, except for the fact that they
operate at different voltage levels. Throughout this
manual, we use the term Sequence of Events module
generically. When you read the term, it refers to both
types of modules unless specifically noted.

Publication 1756-UM528A-EN-P - April 2004
Preface 2
What This Manual Contains
Table Preface.2 lists the sections contained in this manual:
Related Documentation
Table Preface.3 lists related ControlLogix documentation that may
assist you when using the Sequence of Events module.
Table Preface.2
Section: Title:
Chapter 1 What is the ControlLogix Sequence of Events Module?
Chapter 2 How Does the Sequence of Events Module Operate in a
ControlLogix System?
Chapter 3 Installing the Sequence of Events Module
Chapter 4 Configuring the Sequence of Events Module
Chapter 5 Using the Sequence of Events Module Features
Chapter 6 Using The Sequence of Events Module in CST Per Point Mode
Chapter 7 Using The Sequence of Events Module in FIFO Mode
Chapter 8 Troubleshooting the Sequence of Events Module
Appendix A Specifications and Module Block Diagrams
Appendix B Integrating The HiProm GPS Module (1756HP-GPS) into a
ControlLogix Sequence of Events Module System
Appendix C Using the Sequence of Events Module for Absolute First Fault
Detection
Appendix D Using Module Tags
Appendix E Using Sample RSLogix 5000 Projects with the Sequence of Events
Module
Table Preface.3 Related Documentation
Catalog
number:
Document title: Publication
number:
1756-A4, -A7,
-A10, -A13, -A17
ControlLogix Chassis–Series B Installation
Instructions
1756-IN080
1756-PA72/B,
-PB72/B
ControlLogix Power Supply Installation
Instructions
1756-5.67
1756-PA75,
-PB75
ControlLogix Power Supply Installation
Instructions
1756-5.78
1756-PH75 ControlLogix 125V DC (90-143V) Power Supply 1756-IN589
1756-Series ControlLogix Module Installation Instructions
(Each module has separate installation
document.)
Multiple 1756-IN
numbers
1756-CNB,
-CNBR
Using ControlNet Communication Modules in
Logix5000 Control Systems User Manual
CNET-UM001
1756-Lx ControlLogix System User Manual 1756-UM001

Publication 1756-UM528A-EN-P - April 2004
Preface 3
Preventing Electrostatic
Discharge
This module is sensitive to electrostatic discharge.
ATTENTION This equipment is sensitive to electrostatic discharge,
which can cause internal damage and affect normal
operation. Follow these guidelines when you handle
this equipment:
•Touch a grounded object to discharge potential
static.
•Wear an approved grounding wriststrap.
•Do not touch connectors or pins on component
boards.
•Do not touch circuit components inside the
equipment.
•If available, use a static-safe workstation.
When not in use, store the equipment in appropriate
static-safe packaging.

Publication 1756-UM528A-EN-P - April 2004
Preface 4
Environment and Enclosure
ATTENTION This equipment is intended for use in a Pollution
Degree 2 industrial environment, in overvoltage
Category II applications (as defined in IEC
publication 60664-1), at altitudes up to 2000 meters
without derating.
This equipment is considered Group 1, Class A
industrial equipment according to IEC/CISPR
Publication 11. Without appropriate precautions,
there may be potential difficulties ensuring
electromagnetic compatibility in other environments
due to conducted as well as radiated disturbance.
This equipment is supplied as “open type”
equipment. It must be mounted within an enclosure
that is suitably designed for those specific
environmental conditions that will be present and
appropriately designed to prevent personal injury
resulting from accessibility to live parts. The interior
of the enclosure must be accessible only by the use
of a tool. Subsequent sections of this publication
may contain additional information regarding
specific enclosure type ratings that are required to
comply with certain product safety certifications.
See NEMA Standards publication 250 and IEC
publication 60529, as applicable, for explanations of
the degrees of protection provided by different types
of enclosure. Also, see the appropriate sections in
this publication, as well as the Allen-Bradley
publication 1770-4.1 (“Industrial Automation Wiring
and Grounding Guidelines”), for additional
installation requirements pertaining to this
equipment.

1Publication 1756-UM528A-EN-P - April 2004
Table of Contents
Chapter 1
What is the ControlLogix
Sequence of Events Module?
What This Chapter Contains . . . . . . . . . . . . . . . . . . . . . . . 1-1
What does Sequence of Events Module Do? . . . . . . . . . . . . 1-1
Timestamping Using the Coordinated System Time (CST) 1-1
On-Board Data Storage . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Two Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . 1-3
What Else Does the Sequence of Event Module Do? . . . . . . 1-3
Understanding the Module’s Physical Features . . . . . . . . . . 1-4
Using Module Identification and Status Information . . . . . . 1-5
Chapter Summary and What’s Next . . . . . . . . . . . . . . . . . . 1-6
Chapter 2
How Does the Sequence of Events
Module Operate in a ControlLogix
System?
What This Chapter Contains . . . . . . . . . . . . . . . . . . . . . . . 2-1
Differences Between Sequence of Events Module
and Standard Digital I/O . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Similar Functionality to Standard ControlLogix DC
Input Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Propagating a Signal From Field Device to Backplane . . . . 2-4
Sequence of Events Module in a Local Chassis . . . . . . . . . . 2-6
Requested Packet Interval (RPI) . . . . . . . . . . . . . . . . . . 2-6
Enable CST Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Sequence of Events Module in a Remote Chassis . . . . . . . . 2-8
Remote Input Module Connected Via ControlNet . . . . . 2-8
Remote Input Modules Connected Via EtherNet/IP . . . . 2-10
Chapter Summary and What’s Next . . . . . . . . . . . . . . . . . . 2-10
Chapter 3
Installing the Sequence of
Events Module
What This Chapter Contains . . . . . . . . . . . . . . . . . . . . . . . 3-1
Installing the Sequence of Events Module. . . . . . . . . . . . . . 3-1
Keying the Removable Terminal Block. . . . . . . . . . . . . . . . 3-3
Connecting Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
Wiring the RTB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
Recommendations for Wiring Your RTB . . . . . . . . . . . . 3-5
Wiring the Sequence of Events Module . . . . . . . . . . . . . . . 3-6
Assembling The Removable Terminal Block and
the Housing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
Choosing the Extended-Depth Housing . . . . . . . . . . . . . . . 3-8
Recommendations for Using the
Extended-Depth Housing . . . . . . . . . . . . . . . . . . . . . . . 3-9
Cabinet Size Considerations With the
Extended-Depth Housing . . . . . . . . . . . . . . . . . . . . . . . 3-9
Installing the Removable Terminal Block . . . . . . . . . . . . . . 3-10
Removing the Removable Terminal Block . . . . . . . . . . . . . 3-12
Removing the Module from the Chassis . . . . . . . . . . . . . . . 3-13
Chapter Summary and What’s Next . . . . . . . . . . . . . . . . . . 3-14

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Table of Contents 2
Chapter 4
Configuring the Sequence of
Events Module
What This Chapter Contains . . . . . . . . . . . . . . . . . . . . . . . 4-1
Configuring Your I/O Module . . . . . . . . . . . . . . . . . . . . . . 4-1
RSLogix 5000 Configuration Software . . . . . . . . . . . . . . 4-1
Overview of the Configuration Process . . . . . . . . . . . . . . . 4-2
Adding a New Module to Your RSLogix 5000 Project . . . . . 4-3
Communications Format. . . . . . . . . . . . . . . . . . . . . . . . 4-5
Electronic Keying. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
Using the Default Configuration. . . . . . . . . . . . . . . . . . . . . 4-6
Altering the Default Configuration . . . . . . . . . . . . . . . . . . . 4-6
Downloading Configuration. . . . . . . . . . . . . . . . . . . . . . . . 4-7
Editing Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7
Configuring Modules in a Remote Chassis . . . . . . . . . . . . . 4-9
Chapter Summary and What’s Next . . . . . . . . . . . . . . . . . . 4-11
Chapter 5
Using the Sequence of Events
Module Features
What This Chapter Contains . . . . . . . . . . . . . . . . . . . . . . . 5-1
Determining Module Compatibility . . . . . . . . . . . . . . . . . . 5-2
Module Features That Can Be Configured . . . . . . . . . . . . . 5-3
Two Operational Modes. . . . . . . . . . . . . . . . . . . . . . . . 5-3
Enable CST Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
Latch CST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
Chatter Detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
Software Configurable Input Filters. . . . . . . . . . . . . . . . 5-10
Electronic Keying. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13
Module Inhibiting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15
Other Inherent Module Features . . . . . . . . . . . . . . . . . . . . 5-16
Removal and Insertion Under Power (RIUP) . . . . . . . . . 5-16
Module Fault Reporting . . . . . . . . . . . . . . . . . . . . . . . . 5-16
Fully Software Configurable . . . . . . . . . . . . . . . . . . . . . 5-17
Producer/Consumer Model. . . . . . . . . . . . . . . . . . . . . . 5-17
Status Indicator Information . . . . . . . . . . . . . . . . . . . . . 5-18
Full Class I Division 2 Compliance . . . . . . . . . . . . . . . . 5-19
Agency Certifications . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19
Chapter Summary and What’s Next . . . . . . . . . . . . . . . . . . 5-19

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Table of Contents 3
Chapter 6
Using The Sequence of Events
Module in CST Per Point Mode
What This Chapter Contains . . . . . . . . . . . . . . . . . . . . . . . 6-1
Overview of the Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
How Does the Module Store Timestamp Data in CST
Per Point Mode? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
What Are The Typical Applications Where CST Per Point
Mode is Used?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
Configuring the Module for CST Per Point Mode . . . . . . . . 6-4
Choosing a Communications Format. . . . . . . . . . . . . . . 6-5
Using Latch CST in CST Per Point Mode . . . . . . . . . . . . 6-6
Using Enable CST Capture in CST Per Point Mode. . . . . 6-7
Managing the Data in CST Per Point Mode . . . . . . . . . . . . . 6-8
Module Sends Data to the Controller . . . . . . . . . . . . . . 6-8
Copying Relevant Input Data to a Separate
Data Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10
Acknowledging Latched Timestamp Data . . . . . . . . . . . 6-12
Sorting the Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-14
Clearing All Data From the Module’s Buffers At Once. . . . . 6-14
Chapter Summary and What’s Next . . . . . . . . . . . . . . . . . . 6-14
Chapter 7
Using The Sequence of Events
Module in FIFO Mode
What This Chapter Contains . . . . . . . . . . . . . . . . . . . . . . . 7-1
Overview of the Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
How Does the On-Board Buffer Work in FIFO Mode? . . . . 7-2
What the Typical Applications Where FIFO Mode is Used? . 7-4
Configuring the Module for FIFO Mode . . . . . . . . . . . . . . . 7-4
Choosing a Communications Format. . . . . . . . . . . . . . . 7-5
Using Latch CST in FIFO Mode. . . . . . . . . . . . . . . . . . . 7-6
Using Enable CST Capture in FIFO Mode . . . . . . . . . . . 7-9
Managing the Data in FIFO Mode . . . . . . . . . . . . . . . . . . . 7-10
Retrieving Data in FIFO Mode . . . . . . . . . . . . . . . . . . . 7-10
Producing Current Event Data . . . . . . . . . . . . . . . . . . . 7-14
Copying Relevant Input Data to a Separate
Data Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-15
Acknowledging Latched Timestamp Data . . . . . . . . . . . 7-17
Clearing All Data From the Module’s Buffers At Once. . . . . 7-20
Changing Between Retrieval Methods . . . . . . . . . . . . . . . . 7-20
Chapter Summary and What’s Next . . . . . . . . . . . . . . . . . . 7-20

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Table of Contents 4
Chapter 8
Troubleshooting the Sequence of
Events Module
What This Chapter Contains . . . . . . . . . . . . . . . . . . . . . . . 8-1
Using LED Status Indicators . . . . . . . . . . . . . . . . . . . . . . . . 8-1
Using RSLogix 5000 To Troubleshoot the Module. . . . . . . . 8-2
Determining Fault Type . . . . . . . . . . . . . . . . . . . . . . . . 8-4
Chapter Summary and What’s Next . . . . . . . . . . . . . . . . . . 8-4
Appendix A
Specifications and Module
Block Diagrams
1756-IB16ISOE Specifications. . . . . . . . . . . . . . . . . . . . . . . A-1
1756-IB16ISOE Module Block Diagram . . . . . . . . . . . . . . . A-4
1756-IH16ISOE Specifications . . . . . . . . . . . . . . . . . . . . . . A-5
1756-IH16ISOE Module Block Diagram . . . . . . . . . . . . . . . A-8
Appendix B
Integrating The HiProm GPS
Module (1756HP-GPS) into a
ControlLogix Sequence of Events
Module System
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1
What is the 1756HP-GPS Module? . . . . . . . . . . . . . . . . . . . B-2
Correlating CST with UCT . . . . . . . . . . . . . . . . . . . . . . B-2
Determining the Absolute First Fault Across Multiple Chassis B-4
How Does the ControlLogix Controller Retrieve
Converted Value from the 1756HP-GPS Module? . . . . . . . . B-6
Converting Timestamps from CST Format to Universal
Coordinated Time Format . . . . . . . . . . . . . . . . . . . . . . . . . B-8
Appendix C
Synchronizing CSTs Across
Multiple Chassis
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1
Using a Time Master . . . . . . . . . . . . . . . . . . . . . . . . . . C-1
Configuring 1756-SYNCH Modules in RSLogix 5000. . . . C-3
Synchronizing Chassis in ControlLogix Redundancy Systems C-4
Related SynchLink Documentation. . . . . . . . . . . . . . . . . . . C-5
Appendix D
Using Module Tags
Fault and Status Reporting Between the Module
and Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1
Module Tag Names and Definitions . . . . . . . . . . . . . . . . . . D-2
Tags Used in CST Point Per Mode . . . . . . . . . . . . . . . . D-2
Tags Used in FIFO Mode . . . . . . . . . . . . . . . . . . . . . . . D-7
Appendix E
Using Sample RSLogix 5000
Projects with the Sequence of
Events Module
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-1
Accessing the Sample Projects . . . . . . . . . . . . . . . . . . . . . . E-2
Glossary
Index

1Publication 1756-UM528A-EN-P - April 2004
Chapter 1
What is the ControlLogix Sequence of
Events Module?
What This Chapter Contains
This chapter describes the ControlLogix Sequence of Events module.
What does Sequence of
Events Module Do?
The ControlLogix Sequence of Events module is a DC input module
that offers sub-millisecond timestamping on a per point basis in
addition to providing the basic ON/OFF detection as found on other
ControlLogix input modules.
Timestamping is a ControlLogix feature that registers a time reference
to a change in input data. In ControlLogix, the time mechanism used
for timestamping is the Coordinated System Time (CST).
Timestamping Using the Coordinated System Time (CST)
The Coordinated System Time (CST) is a 64-bit, free-running timer
with microsecond (µs) granularity on a ControlLogix backplane. A
time master (either a ControlLogix controller or 1756-SYNCH
module) generates the timer and sets it on the backplane. All other
modules in the chassis have access to the CST and adjust their time
reference based on the backplane time reference.
Table 1.1
For information on: See page:
What does Sequence of Events Module Do? 1-1
What Else Does the Sequence of Event Module Do? 1-3
Understanding the Module’s Physical Features 1-4
Using Module Identification and Status Information 1-5

Publication 1756-UM528A-EN-P - April 2004
1-2 What is the ControlLogix Sequence of Events Module?
CST cannot easily translate to real-time but serves as a relative time
reference. Each module in a chassis has access to this reference. The
Sequence of Events module grabs the current CST value at the time of
the input state change to timestamp the input data.
You can propagate the same CST value across multiple chassis,
effectively making sure that modules in separate chassis use the same
time reference in all their operations, if necessary.
You can extend a single CST value across multiple chassis that are
physically connected via 1756-SYNCH modules. Additionally, multiple
ControlLogix systems–even those that are geographically separated–
can use the 1756HP-GPS module to share a common real-time
reference. For more information on extending a single CST value
across multiple chassis, see Appendix C.
On-Board Data Storage
Once a CST timestamp is captured for an input transition, the
module’s operational mode impacts how the module functions with
respect to:
•what data is stored on-board
•how much data is stored for each input point
•how the data is sent to the controller
The next section briefly describes the two modes of operation
available with the Sequence of Events module and how they impact
the module’s behavior.

Publication 1756-UM528A-EN-P - April 2004
What is the ControlLogix Sequence of Events Module? 1-3
Two Modes of Operation
The Sequence of Events module can operate in either of the modes
described in Table 1.2:
You set the module’s operational mode when you choose a
communication format during initial module configuration.
Depending on operational mode, RSLogix 5000 creates different tags
for the Sequence of Events when it is added to a project.
For more information on each mode, see Chapter 6, Using The
Sequence of Events Module in CST Per Point Mode and Chapter 7,
Using The Sequence of Events Module in FIFO Mode.
What Else Does the
Sequence of Event
Module Do?
The Sequence of Events module offers additional features that are
common to ControlLogix digital input modules, such as:
•Full software configuration via RSLogix 5000
•Removal and insertion under power
•Full Class I Division Compliance
•Agency Certifications (e.g. UL and CSA)
To see a full description of all the features available on your Sequence
of Events module, see Chapter 5, Using the Sequence of Events
Module Features.
Table 1.2
Operational mode: Description:
CST Per Point Mode The module timestamps up to 2 input transitions per input, one for OFF to ON transitions and another
for ON to OFF transitions.
First In First Out (FIFO) Mode The module timestamps an unlimited number of input transitions, regardless of direction (i.e., either
OFF to ON or ON to OFF) or input (i.e., the same input can transition many times and the module will
timestamp every transition) and stores them in an on-board buffer.
The module is capable of storing the data for up to 160 input transitions in its on-board buffers at a
single time. However, if you retrieve data from the buffers effectively, the module will never miss an
input transition, regardless of how many occur.

Publication 1756-UM528A-EN-P - April 2004
1-4 What is the ControlLogix Sequence of Events Module?
Understanding the
Module’s Physical Features
ControlLogix modules mount in a ControlLogix chassis and use a
Removable Terminal Block (RTB), or a Bulletin 1492 Interface Module
cable that connects to an IFM, to connect all field-side wiring. Before
you use your module, you should have already:
•installed and grounded a 1756 chassis and power supply. To
install these products, refer to the publications listed in
Table Preface.3 on page Preface-2.
•ordered and received an RTB or IFM and its components for
your application; neither RTBs nor IFMs are included with your
module purchase.
Figure 1.1
41623
O
K
Indicators Locking tab
Removable terminal
block
Slots
for
keying
the
RTB
Connector
pins
Top and
bottom
guides
ControlLogix
backplane
Jumper
bar
Table 1.3 Physical Features on the ControlLogix Sequence of Events Module
Physical Feature: Description:
Backplane connector The backplane connector interface for the ControlLogix system connects the module to the ControlLogix
backplane.
Connector pins Input/output, power and grounding connections are made to the module through these pins with the use of
an RTB or IFM.
Locking tab The locking tab anchors the RTB or IFM cable on the module, maintaining wiring connections.
Slots for keying Mechanically keys the RTB to prevent inadvertently making the wrong wire connections to your module.
Status indicators Indicators display the status of communication, module health and input/output devices. Use these
indicators to help in troubleshooting.
Top and bottom guides Guides provide assistance in seating the RTB or IFM cable onto the module.
Jumper bar Device you can use to connect multiple points in non-isolated wiring application, as shown on page 3-6.

Publication 1756-UM528A-EN-P - April 2004
What is the ControlLogix Sequence of Events Module? 1-5
Using Module
Identification and
Status Information
Each Sequence of Events 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 be aware
of exactly what modules are located in any ControlLogix chassis at
any time. While retrieving module identity, you can also retrieve the
module’s status.
Each module maintains the information listed in Table 1.4:
Table 1.4 Module Identification and Status Information
Module Identification: Description:
Product Type Module’s product type
Product Code Module’s catalog number
Major Revision Module’s major revision number
Minor Revision Module’s minor revision number
Status Module’s status. Returns the following information:
•Controller ownership (if any)
•Whether module has been configured
•Device Specific Status, such as:
•Self-Test
•Flash update in progress
•Communications fault
•Not owned
•Internal fault (need flash update)
•Run mode
•Minor recoverable fault
•Minor unrecoverable fault
•Major recoverable fault
•Major unrecoverable fault
Vendor ID Module manufacturer vendor, for example Allen-Bradley
Serial Number Module 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.

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1-6 What is the ControlLogix Sequence of Events Module?
Chapter Summary and
What’s Next
In this chapter you read about what the ControlLogix Sequence of
Events module is. Chapter 2 explains How Does the Sequence of
Events Module Operate in a ControlLogix System?

1Publication 1756-UM528A-EN-P - April 2004
Chapter 2
How Does the Sequence of Events Module
Operate in a ControlLogix System?
What This Chapter
Contains
This chapter describes how the Sequence of Events module
operates in a ControlLogix system.
Differences Between
Sequence of Events Module
and Standard Digital I/O
In many aspects, the Sequence of Events module behaves the same as
other ControlLogix digital input modules. However, the module offers
several significant differences from other ControlLogix digital input
modules, including those described in Table 2.2:
Table 2.1
For information on: See page:
Ownership 2-2
Using RSNetWorx and RSLogix 5000 2-2
Propagating a Signal From Field Device to Backplane 2-4
Sequence of Events Module in a Local Chassis 2-6
Sequence of Events Module in a Remote Chassis 2-8
Table 2.2
Difference: Description:
Additional data produced for
controller
The Sequence of Events module produces significantly more data for its owner-controller than
standard ControlLogix digital input modules. While other input modules only produce ON/OFF and
fault status, the Sequence of Events module produces data such as ON/OFF and fault status,
timestamp data, indication of whether new data was produced for specific input points or if
transitions were not timestamped.
Only one owner-controller per module While multiple controllers can simultaneously own other digital input modules, the Sequence of
Events module only supports a single owner-controller.
Rack-optimized connections not
supported
The Sequence of Events module does not support Rack-Optimized Connections from the
owner-controller.
Change of State (COS) functionality in
Enable CST Capture feature
The module does support Enable CST Capture, a feature used to timestamp input transitions, that
is analogous to COS. For more information on Enable CST Capture, see page 2-6.
No listen-only connections Controllers cannot make listen-only connections to the Sequence of Events module. All
connections between the module and its owner-controller are direct connections.
Input filtering on a module-wide basis Other digital input modules offer input filtering on a per group basis. The Sequence of Events
module offers two input filter settings–one for OFF to ON transitions and one for ON to OFF
transitions–and is set on a module-wide basis.

Publication 1756-UM528A-EN-P - April 2004
2-2 How Does the Sequence of Events Module Operate in a ControlLogix System?
Similar Functionality to
Standard ControlLogix DC
Input Modules
With respect to general module operation in a ControlLogix system,
the Sequence of Events module operates similarly to other
ControlLogix digital input modules in many ways. This chapter
focuses on how the Sequence of Events module’s behavior differs
from that of other ControlLogix digital input modules.
However, you should be aware of aspects in which the Sequence of
Events module is similar to standard ControlLogix digital input
modules. For more information on these similarities, see Table 2.3.
Table 2.3 Ways that a Sequence of Events Module Behave Like Other ControlLogix Digital Input Modules
Concept: Description:
Ownership Every Sequence of Events module in the ControlLogix system must be owned by a Logix5000 controller. This
owner-controller:
•stores configuration data for every module that it owns.
•can be local or remote in regard to the Sequence of Events module’s position.
•sends the Sequence of Events module configuration data to define the module’s behavior and begin
operation with the control system.
This module does not support multiple owner-controllers.
Using RSNetWorx and
RSLogix 5000
The I/O configuration portion of RSLogix5000, v13 or greater, generates the configuration data for each
Sequence of Events module in the control system, whether the module is located in a local or remote chassis.
A remote chassis, also known as networked, contains the Sequence of Events module but not the module’s
owner-controller. Remote chassis can be connected to the controller via a scheduled ControlNet or an
EtherNet/IP network.
Configuration data is transferred to the controller during the program download and subsequently transferred
to the appropriate Sequence of Events modules.
Sequence of Events modules in the local chassis, and modules in a remote chassis that is connected via the
EtherNet/IP network, are ready to run as soon as the configuration data has been downloaded. However, you
must run RSNetWorx for ControlNet to enable Sequence of Events modules in a scheduled ControlNet
chassis.
Running RSNetWorx transfers configuration data to Sequence of Events modules on scheduled ControlNet
and establishes a Network Update Time (NUT) for ControlNet that is compliant with the desired
communications options specified for each module during configuration.
Anytime a controller references a Sequence of Events module in a scheduled ControlNet chassis, you must
run RSNetWorx to configure ControlNet. Follow these general guidelines when configuring Sequence of
Events modules:
1. Configure all Sequence of Events modules for a given controller using RSLogix 5000 and download
that information to the controller.
2. If the module configuration data references a module in a remote chassis connected by scheduled
ControlNet, run RSNetWorx.
3. After running RSNetWorx, perform an online save of the RSLogix 5000 project so the configuration
information that RSNetWorx sends to the controller is saved.
IMPORTANT: You must run RSNetWorx whenever a new module is added to a scheduled ControlNet
chassis. When a module is permanently removed from a remote chassis, we recommend that RSNetWorx be
run to optimize the allocation of network bandwidth.

Publication 1756-UM528A-EN-P - April 2004
How Does the Sequence of Events Module Operate in a ControlLogix System? 2-3
Making Connections ControlLogix controllers can make direct or rack connections to digital I/O modules. The controller can only make
a direct connection to the Sequence of Events module. The controller cannot make rack connections to the
Sequence of Events module. Additionally, the controller cannot make listen-only connections to the
Sequence of Events module.
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.
The controller maintains and monitors its connection with a module. Any break in the connection, such as module
faults or removal of the module from the chassis while under power, causes the controller to set fault status bits
in the data area associated with the module. RSLogix 5000 monitors connection status to annunciate the
modules’ failures.
Transmitting Data In the ControlLogix system, a controller does not poll the Sequence of Events module to obtain input status. When
you configure a Sequence of Events module to capture a CST value for a specific transition, the module produces
data whenever that input transitions and also at a user-configured rate. The type of input data transmitted and
transmission frequency depends on module configuration and where in the control system that input module
physically resides.
This is called the Producer/Consumer model. The Sequence of Events module produces the input data and the
controller consumes the data.
All Sequence of Events module inputs are updated asynchronous 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.
Triggering Event
Tasks
You can configure Sequence of Events modules to trigger an event task. The event task offers ControlLogix
controller users a task that executes a section of logic immediately when an event (i.e., receipt of new, unseen,
data) occurs.
Your Sequence of Events module can trigger event tasks. When using a Sequence of Events module to trigger an
event task, remember these considerations:
•Only one input module can trigger a specific event task.
•The input module triggers the event task based on the Enable CST Capture configuration for the module.
The Enable CST Capture 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 CST Capture for only one point on the module. If you Enable CST Capture for multiple
points, a task overlap of the event task may occur.
For more information on using Event tasks, see the Logix5000 Controllers Common Procedures Programming
Manual, publication 1756-PM001.
Table 2.3 Ways that a Sequence of Events Module Behave Like Other ControlLogix Digital Input Modules
Concept: Description:

Publication 1756-UM528A-EN-P - April 2004
2-4 How Does the Sequence of Events Module Operate in a ControlLogix System?
Propagating a Signal From
Field Device to Backplane
As shown in Figure 2.1, the Sequence of Events module receives a
signal at the RTB and processes it internally before sending a signal to
the ControlLogix backplane via the Requested Packet Interval (RPI) or
at na Enable CST Capture occurrence.
However, when you operate the Sequence of Events module, you
must account for signal propagation delays that exist during internal
processing. Some of these delays are inherent to the module and
others can be controlled via the user-defined module configuration.
During processing, the following delays exist:
•hardware delay - varies according to module type (i.e., catalog
number) and input transition type (i.e., OFF to ON/ON to OFF)
•input filter delay - user-configurable number from 0 to 50ms
•firmware scan time - up to 25µs, depending on when the input
transitions relative to the sample time
•ASIC delay - 25µs
Typically, the Sequence of Events module can deliver a signal to the
ControlLogix backplane within 275µs in FIFO mode and 725µs in CST
Per Point mode after it was received at the removable terminal block
(RTB); these 275µs or 725µs numbers represent a scenario where the
hardware delay is at maximum levels but no input filter is used.
IMPORTANT The hardware delay is relatively consistent across
inputs on a module and across modules in a chassis.
Therefore, assuming the inputs and modules are
used in similar environmental conditions and with
similar voltages applied, the hardware delay is a
minor consideration affecting timestamping accuracy.
TIP For fastest propagation of a signal from a field device
to the controller, use the module in FIFO mode in a
local chassis.