Rockwell Automation Allen-Bradley Logix 5000 Series Owner's manual

Rockwell Automation Publication 1756-PM014N-EN-P - March 2022
Supersedes Publication 1756-PM014M-EN-P - September 2020
Programming Manual
Original Instructions
Logix 5000 Controllers
Major, Minor, andI\O
Faults
1756 ControlLogix, 1756 GuardLogix, 1769 CompactLogix,
1769 Compact GuardLogix, 1789 SoftLogix, 5069
CompactLogix, 5069 Compact GuardLogix, Studio 5000
Logix Emulate

Logix 5000 Controllers Major, Minor, and I/O Faults
2 Rockwell Automation Publication 1756-PM014N-EN-P - March 2022
Important User Information
Read this document and thedocuments listed in the additional resources section about installation, configuration, and
operation of this equipment before you install, configure, operate, or maintain this product.Usersare required to familiarize
themselves with installation and wiring instructions in addition to requirements of all applicable codes, laws, and standards.
Activities including installation, adjustments, putting into service, use, assembly, disassembly, and maintenance are required to
be carried out by suitably trained personnel in accordance with applicable code of practice.
If this equipment is used in a manner not specified by the manufacturer, the protection provided by the equipment may be
impaired.
In no event will Rockwell Automation, Inc. be responsible orliable 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.
WARNING: Identifies information about practices or circumstances that can cause an explosion in a hazardous environment, whichmay 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 recognizethe consequence.
IMPORTANT
Identifies information that is critical for successful application and understanding of the product.
Labels may also be on or inside the equipment to provide specific precautions.
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.
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Rockwell Automation Publication 1756-PM014N-EN-P - March 2022 3
Summary of changes
This manual includes new and updated information. Use these reference
tables to locate changed information.
Grammatical and editorial style changes are not included in this summary.
Global changes
The Legal noticeshave been updated.
New or enhanced features
This table contains a list of topics changed in this version, the reason for the
change, and a link to the topic that contains the changed information.
Topic Name
Reason
Minor fault codes on page 29
Replaced the Minor Fault Codes list with a link to the Logix 5000
Controller Fault Codes spreadsheet, which contains a complete list of
fault codes.
Major fault codes on page 25
Replaced the Major Fault Codes list with a link to the Controller Fault
Codes spreadsheet.
I/O fault codes on page 33
Replaced the I/O Fault Codes list with a link to the Controller Fault
Codes spreadsheet.

Rockwell Automation Publication 1756-PM014N-EN-P - March 2022 5
Table of Contents
Studio 5000 environment ...........................................................................7
Additional resources....................................................................................8
Legal Notices ................................................................................................8
Chapter 1
Major Fault State..........................................................................................9
Recover from a major fault....................................................................9
Fault handling during prescan and postscan .................................... 11
Placement of fault routines.................................................................12
Choose where to place the fault routine.............................................13
Create a fault routine for a program.........................................................13
Change a fault routine assignment of a program .............................14
Create a routine for the controller fault handler .....................................16
Create a routine for the power-up handler ..............................................17
Programmatically clearing a major fault.................................................20
Create a data type to store fault information ...................................20
Write a routine to clear the fault.........................................................21
Clear a major fault during prescan .......................................................... 22
Test a fault routine.................................................................................... 24
Create a user-defined major fault............................................................ 24
Major fault codes....................................................................................... 25
Chapter 2
Identify minor faults .................................................................................27
Minor fault examples...........................................................................28
Minor fault codes....................................................................................... 29
Chapter 3
Indications of I/O faults.............................................................................31
I/O Fault Codes .......................................................................................... 33
Summary of changes
Preface
Major Faults
Minor Faults
I/O Fault Codes
Index

Rockwell Automation Publication 1756-PM014N-EN-P - March 2022 7
Preface
This manual shows how to monitor and handle major and minor controller
faults. The manual also provides lists of major, minor, and I/O fault codes to
use to troubleshoot the system.
This manual is one of a set of related manuals that show common procedures
for programming and operating Logix 5000 controllers.
For a complete list of common procedures manuals, refer to the Logix 5000
Controllers Common Procedures Programming Manual, publication
1756-PM001.
The term Logix 5000 controller refers to any controller based on the Logix
5000 operating system.
The Studio 5000 Automation Engineering & Design Environment® combines
engineering and design elements into a common environment. The first
element is the Studio 5000 Logix Designer® application. The Logix Designer
application is the rebranding of RSLogix 5000® software and will continue to
be the product to program Logix 5000™ 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. The Studio
5000 environment is the one place for design engineers to develop all
elements of their control system.
Studio 5000 environment

Preface
8 Rockwell Automation Publication 1756-PM014N-EN-P - March 2022
These documents contain additional information concerning related
products from Rockwell Automation.
Resource
Description
Logix5000 Controllers General Instructions Reference
Manual, publication 1756-RM003
Provides programmers with details about each
available instruction for a Logix5000 controller.
Product Certifications website, http://www.ab.com
Providesdeclarations ofconformity, certificates, and
other certification details.
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.
Rockwell Automation publishes legal notices, such as privacy policies, license
agreements, trademark disclosures, and other terms and conditions on the
Legal Notices page of the Rockwell Automation website.
End User License Agreement (EULA)
You can view the Rockwell Automation End-User License Agreement ("EULA")
by opening the License.rtf file located in your product's install folder on your
hard drive.
Open Source Licenses
The software included in this product contains copyrighted software that is
licensed under one or more open source licenses. Copies of those licenses are
included with the software. Corresponding Source code for open source
packages included in this product are located at their respective web site(s).
Alternately, obtain complete Corresponding Source code by contacting
Rockwell Automation via the Contact form on the Rockwell Automation
website:
http://www.rockwellautomation.com/global/about-us/contact/contact.page
Please include "Open Source" as part of the request text.
A full list of all open source software used in this product and their
corresponding licenses can be found in the OPENSOURCE folder. The default
installed location of these licenses is C:\Program Files (x86)\Common
Files\Rockwell\Help\<Product Name>\Release
Notes\OPENSOURCE\index.htm.
Additional resources
Legal Notices

Rockwell Automation Publication 1756-PM014N-EN-P - March 2022 9
Chapter 1
Major Faults
This chapter explains major fault codes and how to work with them in the
Logix Designer application.
If a fault condition occurs that prevents an instruction from running, the
instruction aborts and the controller reports a major fault. A major fault halts
logic execution and the controller switches to faulted mode (the OK LED
flashes red).
Depending on the application, you may not want all major faults to shut down
the system. If you do not want all major faults to shut down the system, create
a fault routine to clear the fault and let the application continue to run.
The process of resuming execution after the fault clears is known as fault
recovery.
IMPORTANT
Do not use fault routines to continually clear all faults on the controller. Program the fault
routine to be selective in the types and number of faults cleared. It is also a good idea to log
the fault occurrence to analyze it later.
IMPORTANT
When an instruction generates an error due to a fault (for example, a COP with an indirect
addressing programming error), the fault routine skips the instruction and does not run. This
occurs with all instructions.
Example:
In a system that uses recipe numbers as indirect addresses, an incorrectly typed number could
produce a major fault.
To keep the entire system from shutting down in the event of this fault, program a fault routine to
clear type 4, code 20, major faults.
See also
Create a routine for the controller fault handler on page 16
Clear a major fault during prescan on page 22
These examples show fault routines with logic that take specific action after a
major fault. If the fault clears, the faulted instruction does not run and
execution resumes with the next instruction.
Major Fault State
Recover from a major fault

Chapter 1 Major Faults
10 Rockwell Automation Publication 1756-PM014N-EN-P - March 2022
Example 1
In this example, a JSR instruction passes an input parameter containing an
indirect address that is out of bounds. If the fault clears, the JSR instruction
aborts (the subroutine does not run) and execution resumes with the EQU
instruction.
Example 2
In this example, the logic inside an Add-On Instruction generates a fault.
While the logic of an Add-On Instruction may look like a subroutine, it is not–
the Add-On Instruction is an instruction. When a fault occurs inside an
Add-On Instruction, the remainder of the Add-On Instruction aborts. If the
fault clears, execution resumes with the MOV instruction.
Important points regarding Add-On Instructions
Keep these considerations in mind when using Add-On Instructions and
major faults.

Chapter 1 Major Faults
Rockwell Automation Publication 1756-PM014N-EN-P - March 2022 11
•The Add-On Instruction stops running at the instruction that caused
the fault. This means that the remainder of the scan mode routine does
not run.
•If the fault clears, execution resumes at the instruction following the
top-level Add-On Instruction invocation. For example, assume the
Add-On Instruction myAoi in Example 2 invokes a nested Add-On
Instruction myNested, which invokes another nested Add-On
Instruction inner. Furthermore, assume that an instruction inside of
innercauses a fault. If the fault clears, execution resumes with the
MOV instruction (the remainder of inner does not execute; the
remainder of myNested does not execute; and the remainder of myAoi
does not execute.)
•During prescan:
•The Logic routine runs (in prescan mode).
•The Prescan routine runs (in normal scan mode).
•During postscan:
•The Logic routine runs (in postscan mode).
•The Postscan routine runs (in normal scan mode).
If a fault occurs while processing the Logic routine, the Add-On Instruction
aborts (the remainder of the Logic routine does not run and the pre-scan and
post-scan routines do not run). If the fault clears, execution resumes at the
instruction following the top-level Add-On Instruction invocation.
See also
Create a fault routine for a program on page 13
The behavior of each instruction variesdepending on the mode in which it
runs–true, false, prescan, or postscan. For details about what a specific
instruction does in each mode, see the Logix 5000 Controllers General
Instructions Reference Manual, publication number 1756-RM003.
•Prescan provides a system-defined initialization of the user program
when the controller switches from program mode to run mode.
•Postscan provides a system-defined re-initialization of the logic
invoked from an SFC action, when the action shuts down (if SFCs are
configured for Automatic Reset).
If an array index is out of range during prescan, the controller could generate
a major fault. There are a number of ways this could happen: the controller
loses power, encounters a major fault, or the project is saved while online.
Because the user program, during prescan and postscan, cannot assign values
to tags, the only way to correct these issues is to manually initialize the index
variables using the Logix Designer application or to write a fault handler to
ignore the array faults during prescan. To reduce the need for manual
Fault handling during
prescan and postscan

Chapter 1 Major Faults
12 Rockwell Automation Publication 1756-PM014N-EN-P - March 2022
intervention, the Logix Designer application includesan internal fault
handler. This handler is only used during prescan and only clears array faults
(type 4, fault codes of 20 of 83).
Tip: Array faults are not ignored during postscan because the user program controls index tag values when
an action is shut down.
Use a fault routine to program logic to take specific action after a fault, such
as clearing the fault and continuing to run. Configure fault routines to a
program, controller, or to the Power-Up Handler.
ProgramFaultRoutine
ControllerFaultRoutine
Power-UpFaultHandlerRoutine
See also
Create a fault routine for a program on page 13
Create a routine for the controller fault handler on page 16
Create a routine for the power-up handler on page 17
Placement of fault routines

Chapter 1 Major Faults
Rockwell Automation Publication 1756-PM014N-EN-P - March 2022 13
Where to place the fault routine depends on the type of fault. Use this table to
determine where in the project to configure the fault routine.
To clear the fault when
See this section
Condition
Fault Type
The execution of an instruction faults
4
Creating a Fault Routine for a Program
Communication with an I/O module fails 3 Creating a Routine for the Controller Fault
Handler
Watchdog timer for a task expires
6
A motion axis faults
11
The controller powers up in Run or Remote Run
mode
1
Creating a Routine for the Power-Up
Handler
See also
Create a fault routine for a program on page 13
Create a routine for the controller fault handler on page 16
Create a routine for the power-up handler on page 17
Configure any routine as the fault routine for a program. The routine
executes when a program fault occurs before the controller transitions to
fault mode.
To create a fault routine for a program:
1. Open the project in the Logix Designer application.
2. In the Controller Organizer, right-click MainProgram and select
Add>New Routine.
3. On the NewRoutine dialog box, in Name, type the name of the
routine.
Choose where to place the
fault routine
Create a fault routine for a
program

Chapter 1 Major Faults
14 Rockwell Automation Publication 1756-PM014N-EN-P - March 2022
4. (optional) In Description, type a description of the routine.
5. In Type, use the default setting, Ladder Diagram.
6. In In Program or Phase, use the default setting, MainProgram.
Tip: If creating a fault routine for the Power-Up Handler or Controller Fault Handler, specify the
program name of either program in In Program or Phase.
7. In Assignment, select Fault.
8. (optional) Select Open Routine to immediately open the ladder logic
program.
9. Select OK.
See also
Create a routine for the controller fault handler on page 16
Create a routine for the power-up handler on page 17
Choose where to place the fault routine on page 13
Complete these steps to change the routine assigned as the fault routine.
To change a fault routine assignment of a program:
1. In the Controller Organizer, expand the MainTask.
Change a fault routine
assignment of a program

Chapter 1 Major Faults
Rockwell Automation Publication 1756-PM014N-EN-P - March 2022 15
If there is already a fault routine, it appears in the MainProgram.
2. Right-click MainProgram and select Properties.
3. On the Program Properties - MainProgram dialog box, select the
Configuration tab.
4. In Fault, choose the routine to be the program’s fault routine.
5. Select OK.
The program specified in step 4 is now indicated as the fault routine in
the MainProgram.
See also
Create a fault routine for a program on page 13

Chapter 1 Major Faults
16 Rockwell Automation Publication 1756-PM014N-EN-P - March 2022
Use these steps to create a fault routine to operate as the controller fault
handler. Program tags are automatically created during this process.
IMPORTANT
When programming the fault handler, remember that any instruction that is skipped as part
of the fault-handling program does not run when the main tasksand associated programs
run.
For example, if the fault handler skips a JSR instruction that is causing a major fault, then
that JSR instruction, including all of the programming within the subroutine, does not run.
When an instruction generates an error due to a fault (for example, a COP with an indirect
addressing programming error), the instruction is skipped and does not run. This occurs
with all instructions.
To create a routine for the controller fault handler:
1. In the Controller Organizer, right-click Controller Fault Handler and
select NewProgram.
2. On the NewProgram dialog box, in Name, type a program name.
Verify that Schedule in is set to Controller Fault Handler.
3. Select OK.
Create a routine for the
controller fault handler

Chapter 1 Major Faults
Rockwell Automation Publication 1756-PM014N-EN-P - March 2022 17
4. In the Controller Organizer, right-click the program created in step 2
and select Add>New Routine.
5. On the NewRoutine dialog box, in Name, type a name for the routine.
6. In Type, choose the type of routine to create. The default is Ladder
Diagram.
7. In Assignment, use the default setting, Main.
Tip: Even though Fault is an option in the Assignment, assigning the routine as a fault routine within
the Controller Fault Handler is not necessary.
8. Select OK.
The fault routine is created in the Controller Fault Handler program.
9. Double-click the fault routine to edit it.
See also
Recover from a major fault on page 9
Fault handling during prescan and postscan on page 11
The Power-Up Handler is an optional task that executes when the controller
powers up in Run or Remote Run modes.
To
Do this
Prevent the controller from returning to Runor
Remote mode
Leave the routine for the Power-Up Handler empty. When
power restored, a major fault (type 1, code 1) occurs and the
controller enters the faulted state.
Direct the controller to take specific actions, then
resume normal operation when power restored
In the Power-Up Handler fault routine, complete these steps.
1. Clear the major fault (type 1, code 1).
2. Run the appropriate logic for the specificactions required.
Create a routine for the
power-up handler

Chapter 1 Major Faults
18 Rockwell Automation Publication 1756-PM014N-EN-P - March 2022
IMPORTANT
Do not use fault routines to continually clear all faults on the controller. Program the fault
routine to be selective in the types and number of faults cleared.
IMPORTANT
When an instruction generates an error due to a fault (for example, a COP with an indirect
addressing programming error), the routine skips the instruction and the instruction does
not run. This occurs with all instructions.
To create a routine for the power-up handler:
1. In the Controller Organizer, right-click Power-Up Handler and select
New Program.
2. On the NewProgram dialog box, in Name, type a program name.

Chapter 1 Major Faults
Rockwell Automation Publication 1756-PM014N-EN-P - March 2022 19
3. Select OK. The program is added to the Power-Up Handler.
4. Right-click the program you created in step 2 and click
Add>New Routine.
5. On the NewRoutine dialog box, in Name, type the name of the
routine.
6. In Assignment, keep the default setting, Main.
Tip: Even though Fault is an option in Assignment, assigning the routine as a fault routine within the
Power-Up Handler is not necessary.
7. Click OK. The fault routine is added to the Power-Up Handler.

Chapter 1 Major Faults
20 Rockwell Automation Publication 1756-PM014N-EN-P - March 2022
8. Double-click new routine to edit.
See also
Major fault codes on page 25
To programmatically clear a major fault that occurs during the execution of
the project:
•Create a data type to store fault information
•Write a fault routine to clear the fault
IMPORTANT
Do not use fault routines to continually clear all faults on the controller. Program the fault
routine to be selective in the types and number of faults cleared.
IMPORTANT
When an instruction generates an error due to a fault (for example, a COP with an indirect
addressing programming error), the routine skips the instruction and the instruction does
not run. This occurs with all instructions.
See also
Create a data type to store fault information on page 20
Write a routine to clear the fault on page 21
Logix 5000 controllers store system information in objects. Unlike PLC-5 or
SLC 500 controllers, there is no status file.
•To access system information, use a Get System Value (GSV) or Set
System Value (SSV) instruction.
•To get status information about a program, access the Program object.
•To get fault information for the program, access the MajorFaultRecord
attribute of the Program object.
Attribute
Data Type
Instruction
Description
MajorFaultRecord
DINT[11]
GSV
SSV
Records major faults for this program.
Specifies the program name to determine which
Program objectto use, or specifies THIS to access
the Program object for the program that contains the
GSV or SSV instruction.
To simplify access to the MajorFaultRecord attribute, complete these steps to
create a user-defined data type.
Programmatically clearing
a major fault
Create a data type to store
fault information