This document outlines a basic troubleshooting course that teaches a functional search strategy using sensory input, filtering, action, and documentation to systematically identify the root cause of malfunctions in industrial processes, with the goal of improving troubleshooting effectiveness and reducing downtime.
RCA is a part of Problem Management and basic tool for Problem and Error Control.
This document should help you to understand Root Cause Analysis more closely
Enjoy learning
- Loved it ? Like it here and ask me for a copy :-)
In order to prevent a breakdown or a sudden failure of the equipment in the workplace, organization need to monitor the maintenance of equipment's and prevent problems before it occurs.
It refers to a regular examine and routine maintenance, which helps in keeping equipment up and running.
It is a planned maintenance of the plant and equipment's which is designed to improve equipment life and avoid any sudden failure.
It includes painting, lubrication, cleaning, adjusting and component replacement to prolong the useful life of the production equipment.
RCA is a part of Problem Management and basic tool for Problem and Error Control.
This document should help you to understand Root Cause Analysis more closely
Enjoy learning
- Loved it ? Like it here and ask me for a copy :-)
In order to prevent a breakdown or a sudden failure of the equipment in the workplace, organization need to monitor the maintenance of equipment's and prevent problems before it occurs.
It refers to a regular examine and routine maintenance, which helps in keeping equipment up and running.
It is a planned maintenance of the plant and equipment's which is designed to improve equipment life and avoid any sudden failure.
It includes painting, lubrication, cleaning, adjusting and component replacement to prolong the useful life of the production equipment.
[Note: To download the complete presentation, visit:
https://www.oeconsulting.com.sg/training-presentations]
Autonomous Maintenance (Jishu Hozen) is one of the most important building blocks in any Total Productive Maintenance (TPM) program. Autonomous Maintenance refers to TPM activities that involve operators in maintaining their own equipment, independent of the maintenance department.
One of the basic principles of TPM is that operators are the first line of defense against unplanned equipment downtime. Operators and others in daily contact with equipment can use their knowledge and familiarity with operating conditions to predict and prevent breakdowns and other equipment-related losses. They do this through regular cleaning and inspection of equipment, and through team-based autonomous. maintenance activities that tackle equipment-related problems.
Activities in an Autonomous Maintenance program include: daily inspections, lubrication, parts replacement, simple repairs, abnormality detection and precision checks.
The goals of the Autonomous Maintenance program are to prevent equipment deterioration, restore equipment to its ideal state, and establish basic conditions needed to keep equipment well maintained.
Developed by our JIPM-certified TPM instructor, this Autonomous Maintenance (Jishu Hozen) PPT presentation is packed with diagrams, examples and practical tips and can be used to train shopfloor staff participating in autonomous maintenance activities.
LEARNING OBJECTIVES
1. Understand the key concepts of TPM and AM activities
2. Learn how to implement the AM activities, step by step
3. Learn how to use activity boards, meetings and one-point lessons to promote TPM goals
4. Learn how to measure and audit AM activities and performance
5. Familiarize with the JIPM TPM excellence criteria for AM
6. Understand the critical success factors in sustaining AM activities on the shopfloor
What is poka yoke?, Classification of poke yoke Poka, What Causes Defects?, Why is it important?, When to use it?, Step by step process in applying poka-yoke, Characteristics of Poka Yoke devices, ADVANTAGES and LIMITATIONS.
This presentation is equipped with the basic concepts of Condition Monitoring. The methods and analysis, circumscribed by Condition Monitoring, are summarized with an addition of application in this presentation.
[Note: To download the complete presentation, visit:
https://www.oeconsulting.com.sg/training-presentations]
Autonomous Maintenance (Jishu Hozen) is one of the most important building blocks in any Total Productive Maintenance (TPM) program. Autonomous Maintenance refers to TPM activities that involve operators in maintaining their own equipment, independent of the maintenance department.
One of the basic principles of TPM is that operators are the first line of defense against unplanned equipment downtime. Operators and others in daily contact with equipment can use their knowledge and familiarity with operating conditions to predict and prevent breakdowns and other equipment-related losses. They do this through regular cleaning and inspection of equipment, and through team-based autonomous. maintenance activities that tackle equipment-related problems.
Activities in an Autonomous Maintenance program include: daily inspections, lubrication, parts replacement, simple repairs, abnormality detection and precision checks.
The goals of the Autonomous Maintenance program are to prevent equipment deterioration, restore equipment to its ideal state, and establish basic conditions needed to keep equipment well maintained.
Developed by our JIPM-certified TPM instructor, this Autonomous Maintenance (Jishu Hozen) PPT presentation is packed with diagrams, examples and practical tips and can be used to train shopfloor staff participating in autonomous maintenance activities.
LEARNING OBJECTIVES
1. Understand the key concepts of TPM and AM activities
2. Learn how to implement the AM activities, step by step
3. Learn how to use activity boards, meetings and one-point lessons to promote TPM goals
4. Learn how to measure and audit AM activities and performance
5. Familiarize with the JIPM TPM excellence criteria for AM
6. Understand the critical success factors in sustaining AM activities on the shopfloor
What is poka yoke?, Classification of poke yoke Poka, What Causes Defects?, Why is it important?, When to use it?, Step by step process in applying poka-yoke, Characteristics of Poka Yoke devices, ADVANTAGES and LIMITATIONS.
This presentation is equipped with the basic concepts of Condition Monitoring. The methods and analysis, circumscribed by Condition Monitoring, are summarized with an addition of application in this presentation.
Continuous integration using Jenkins and SonarPascal Larocque
Continuous Integration can help your to team release features faster. It reduces the risk of deployment issue and will speed up your development cycle. In this presentation we take a look at how Jenkins and Sonar can help you Test, Analyze, Deploy and gather performance metrics that will help your team increase their development quality and reduce deployment time
You work with software, and you feel overwhelmed. You test to learn, and the more you dig the more you find to dig. The development of the product is a constant surprise, and you can hear the product manager thinking “how hard can this be?”.
Oh, well, it turns out is can be pretty hard. As systems go, software is a great specimen, albeit an elusive one.
In this short talk we’ll take the elusiveness out and understand that software systems are complex entities that should be treated and acknowledged as such. We’ll learn about instrumental classic papers that can help us get started on thinking about software systems. Come with questions, leave with more :)
Key Takeaways:
• Discover how complex software systems lead to complex software testing
• Learn why you need skills that allow you to extract information from empiric experiments
• Learn to accept and cope with complexity and make systems more manageable
View webinar here: http://testhuddle.com/resource/software-well-its-complicated/
CAPA management, corrective and preventive action, Rootcause analysis, RCA, Problem mapping, FMEA, Failure Mode effect and Analysis, Fault Tree analysis, Fishbone : ISHIKAWA, CTQ Tree (Critical to Quality Tree), AFFINITY DIAGRAM, 5 Why’s, Human errors,
Step Up Your Data Security Against Third-Party RisksEvan Francen
This presentation was delivered to the Hacks & Hops event attendees in the Spring of 2019. The event featured a short keynote following by a moderated panel discussion. The panel experts provided excellent guidance for all risk managers, CISOs, vendor managers, etc.
Empirical Methods in Software Engineering - an Overviewalessio_ferrari
A first introductory lecture on empirical methods in software engineering. It includes:
1) Motivation for empirical software engineering studies
2) How to define research questions
3) Measures and data collection methods
4) Formulating theories in software engineering
5) Software engineering research strategies
Find the videos at: https://www.youtube.com/playlist?list=PLSKM4VZcJjV-P3fFJYMu2OhlTjEr9Bjl0
تتحدث هذه المحاضرة عن تحليل أسباب جذور المشكلة أو
Root Cause Analysis (RCA)
وهي أداة يتم استخدامها بغرض معرفة جذر أو جذور أسباب مشكلة ما ومن ثم وضع الحل المناسب لعدم تكرار حدوث المشكلة
قمت في هذه المحاضرة بتعريف تحليل أسباب جذور المشكلة او ال
Root Cause Analysis (RCA)
والمبادئ التي يقوم عليها وأنه يركز على تقديم حلول جذرية تمنع عودة المشكلة مرة أخرى بدلا عن التركيز على وضع حلول وقتية لأعراض المشاكل
قمت بعد ذلك بتوضيح خطوات تحليل أسباب جذور المشكلة او ال
Root Cause Analysis (RCA)
متطرقا لعدة أدوات تستخدم في تحليل أسباب جذور المشكلة او ال
Root Cause Analysis (RCA).
1. BASIC TROUBLESHOOTING
STRATEGY
Developing a
Functional Search Strategy for an
Effective Basic
Troubleshooting Process
Developed and presented by Bob Lonzo
BASIC TROUBLESHOOTING
2. COURSE OVERVIEW
• Course Objectives
• What is troubleshooting?
• Troubleshooter Styles
• Basic Troubleshooting
Search Strategy
• Using the Troubleshooting Tools
• Review and Evaluation
BASIC TROUBLESHOOTING
3. COURSE OBJECTIVES
This course is designed to present to
the participant a Basic Troubleshooting
Search Strategy that can be used to
troubleshoot and identify malfunctions
in any type of industrial process
environment.
BASIC TROUBLESHOOTING
4. COURSE OBJECTIVES
Upon completion of this course, the participants
will be able to;
• Apply basic troubleshooting search strategies to several
different process problem scenarios and effectively
identify a malfunction.
• Identify the components and documentation
associated with troubleshooting plant floor systems
and their work areas.
• Use the identified components and documentation
to identify the root cause of a malfunction.
BASIC TROUBLESHOOTING
5. COURSE OBJECTIVES
Upon completion of this course
the participant will be able to:
• Identify the various troubleshooting
styles and list the advantages and
disadvantages for each.
• List the elements in the Basic
Troubleshooting Strategy.
• Demonstrate the how to utilize
machine HMI screen to obtain data.
BASIC TROUBLESHOOTING
6. COURSE OBJECTIVES
• Demonstrate the how to utilize
WD machine drawings
to obtain data.
• Demonstrate the how to utilize
control system indicators
to obtain data.
• Demonstrate the how to utilize
machine manuals to obtain data.
• Prepare a maintenance repair
document for use in their
daily activities.
BASIC TROUBLESHOOTING
7. Housekeeping
• Start / Stop Time
• Breaks
• Lunch Break
• Safety Concerns
Adhere to all Plant Safety rules
Evacuation Route
BASIC TROUBLESHOOTING
9. TROUBLESHOOTING DEFINED
The Definition TROUBLESHOOTER is;
• A person skilled at solving or
anticipating problems or difficulties.
• A skilled worker employed to locate
trouble and make repairs in machinery
and technical equipment.
• An expert in resolving diplomatic or
political disputes a mediator of
disputes that are at an impasse.
BASIC TROUBLESHOOTING
12. BASIC TROUBLESHOOTING
WANDERER
• Relies completely on random chance to
find the problem!
• Logical sequence not followed!
• Requires little knowledge of
troubleshooting strategy!
• Forgets what already has been tested!
• Tends to waste time and effort!
BASIC TROUBLESHOOTING
13. BASIC TROUBLESHOOTING
WANDERER
• Conducts exhaustive search by checking
everything in the system!
• Gets lost in the search!
• Lack schematic interpretation and
component diagnostic skills!
• Limited system understanding!
BASIC TROUBLESHOOTING
14. TROUBLESHOOTING STYLES
RISK TAKERS
• Reconfigures the system to
provide new information!
• Very dangerous to both
equipment and personnel!
• Likes to experiment with
components within a system!
• Must use extreme care not to
introduce new faults!
BASIC TROUBLESHOOTING
15. TROUBLESHOOTING STYLES
ODDSMAKERS
• Rely on knowledge of
common fault occurrences!
• Bet on what they think is the
correct solution based on
symptoms they recognize!
• Troubleshooting requires an
increasing level of skill!
• Quickly become Wanderers!
BASIC TROUBLESHOOTING
16. TROUBLESHOOTING STYLES
SWAPPER
• Most encouraged form of gambling!
• Can be very efficient!
• Can quickly get the equipment
functioning!
• Exhibits risk-taking behavior!
BASIC TROUBLESHOOTING
17. TROUBLESHOOTING STYLES
SWAPPER
• Can damage good parts!
• Limited to supply of spare parts!
• Limited to easily substituted or
modular parts!
BASIC TROUBLESHOOTING
19. TROUBLESHOOTING STYLES
SENSORS
• Likes to look, listen, touch, and smell!
• Valuable strategy for obtaining important
information!
• Rarely a stand-alone problem
solving method!
BASIC TROUBLESHOOTING
20. TROUBLESHOOTING STYLES
TRACERS
• Generally use
schematics/prints!
• Performs voltage checks,
continuity
checks, or signal tracing!
• Start at a known good point in
the
system and work toward the
fault!
BASIC TROUBLESHOOTING
21. TROUBLESHOOTING STYLES
TRACERS
• Start from a faulty symptom
and
search backward to the
error’s
source!
• Depends heavily on good test
equipment and
schematic/print
reading skills!
BASIC TROUBLESHOOTING
22. TROUBLESHOOTING STYLES
SPLITTERS
• Divide & Conquer!
• Half split method!
• Successive approximation!
• Divide a system or circuit in half
and check for proper readings,
then continue to divide and check!
• Use jumper wires
BASIC TROUBLESHOOTING
23. TROUBLESHOOTING STYLES
SPLITTERS
• Disconnect portions of a system
or circuit!
• May contribute to confusion
because of the induced interaction
of components!
• Potential for damage to equipment
or injury to personnel!
BASIC TROUBLESHOOTING
25. TROUBLESHOOTING STYLES
READER
• Least skilled form of the
“Thinking” approach!
• Highly recommended in many
situations!
• Instances still arise to
troubleshoot manually!
• Must be able to switch to
another style of troubleshooting!
BASIC TROUBLESHOOTING
26. TROUBLESHOOTING STYLES
RECALLERS
• Rely more on their memory of
symptoms and solutions from
many years of experience!
• Troubleshooting needs continual
practice!
• Tend to lose troubleshooting skills!
• Solve common problems in familiar
systems!
BASIC TROUBLESHOOTING
27. TROUBLESHOOTING STYLES
DESIGNERS
• Use theoretical knowledge to
evaluate faults!
• Rarely efficient!
BASIC TROUBLESHOOTING
28. TROUBLESHOOTING STYLES
ANALYZERS
• Highly skilled troubleshooters!
• Use system knowledge and
observations (sight) of symptoms
to eliminate portions of a system
in a logical way!
BASIC TROUBLESHOOTING
29. TROUBLESHOOTING STYLES
ANALYZERS
• Requires a detailed understanding
of the system!
• Think before you approach!
• Relies on
FUNCTIONAL SEARCH STRATEGIES
BASIC TROUBLESHOOTING
30. TROUBLESHOOTING STYLES
What is your Troubleshooting style?
• GAMBLER
Wanderer, Risk Taker,
Oddsmaker, Swapper
• TESTER
Sensor, Tracer, splitter
• THINKER
Reader, Re-caller,
Designer, Analyzer
BASIC TROUBLESHOOTING
31. TROUBLESHOOTING STYLES
• List any advantages to being a SWAPPER.
• List the disadvantage to being a SPLITTER.
• Of all of the Troubleshooting
Styles presented, which Style
is the least efficient?
• Which Style is most efficient?
BASIC TROUBLESHOOTING
32. THE BASIC TROUBLESHOOTING
STRATEGY
SENSORY INPUT FILTERING ACTION
FILTER THE FILTER RE-ACTION
NO
YES
PROBLEM
DOCUMENTATION
SOLVED REPAIR
BASIC TROUBLESHOOTING
33. THE BASIC TROUBLESHOOTING
STRATEGY
• SENSORY INPUT
Comprehension of the elements of observation
• FILTERING
Skill set for determining root cause of problems
• ACTION
Introduction to elements of hardware/software/documentation
to implement root cause analysis
BASIC TROUBLESHOOTING
34. THE BASIC TROUBLESHOOTING
STRATEGY
• REPAIR
Show examples of necessary items
and information needed to affect repair
• DOCUMENTATION
Importance of documenting repairs
BASIC TROUBLESHOOTING
35. THE BASIC TROUBLESHOOTING
STRATEGY
SENSORY INPUT
What is Sensory Input?
• Using your senses to gather data on the
problem.
• Every malfunction leaves certain clues
as to where the problem occurred and what
is needed to start the troubleshooting
process.
• The more adept a you are at recognizing
the clues, the more information you will
have to accurately determine root cause
BASIC TROUBLESHOOTING
36. THE BASIC TROUBLESHOOTING
STRATEGY
SENSORY INPUT
Examples of sensory input:
• Visual Inspection of Machine
• Reference HMI device
• Listening to the Operator
• Checking Visual Indicators on
Modules and Components
BASIC TROUBLESHOOTING
37. THE BASIC TROUBLESHOOTING
STRATEGY
SENSORY INPUT
How do you Improve Sensory Acuity?
How does any brilliant idea ever come to
people?
• A person takes something he already
knows and thinks about it in a different
way.
• Questions like “What if-“ and “Imagine if”
spark different avenues of thought.
BASIC TROUBLESHOOTING
38. THE BASIC TROUBLESHOOTING
STRATEGY
SENSORY INPUT
• When is the best time to do troubleshooting
on a machine?
When it is operating correctly.
• What if you could see the machine from
a slightly different perspective every
time you look or listen or smell it?
• How much intuitive knowledge would you
have about its processes or its sequencing?
BASIC TROUBLESHOOTING
39. THE BASIC TROUBLESHOOTING
STRATEGY
FILTERING
Root Cause Concept
• Filtering through the different
sensory input should give you a
prioritized list of possible root
causes.
• This process is done mentally with
deduction or, sometimes,
induction.
BASIC TROUBLESHOOTING
40. THE BASIC TROUBLESHOOTING
STRATEGY
FILTERING
Root Cause Concept
• Assumption is the enemy of deduction.
Sometimes, problems that occur may
have the same symptoms but be an
entirely different cause.
• How many times have you found
yourself inventing obscure reasons
to justify a cause that you just
KNOW it has to be and find that it was
Something else entirely?
BASIC TROUBLESHOOTING
41. THE BASIC TROUBLESHOOTING
STRATEGY
FILTERING
• As you learn and gain
experience from a certain
machine line, your filtering
becomes more acute and
your first root cause
possibility will tend to be
the right one.
BASIC TROUBLESHOOTING
42. THE BASIC TROUBLESHOOTING
STRATEGY
ACTION
From Thought to Action
• After a likely root cause is formulated,
some type of action will be required
to prove the supposition out.
• We will make suggestions of the actions
that need to be taken to trace, diagnose,
and/or reference information in the
Control system.
BASIC TROUBLESHOOTING
43. THE BASIC TROUBLESHOOTING
STRATEGY
ACTION
Examples of typical action skills are:
• PLC Logic Tracing
• Searching and Cross-Referencing
• Referencing WD Prints
• Physical Inspection of Machine
Components
• Trend Data Monitoring
BASIC TROUBLESHOOTING
44. THE BASIC TROUBLESHOOTING
STRATEGY
FILTERING THE FILTER
The “Other Root Cause”
• Sometimes, first impressions
can be incorrect.
• If root cause is not found from
the current action, the subsequent
possibilities must be explored until
a root cause is found.
BASIC TROUBLESHOOTING
45. THE BASIC TROUBLESHOOTING
STRATEGY
FURTHER ACTION
Re-Action on the Filter
• After an alternate root cause is
determined, all steps listed in the
ACTION step listed above can be
re-used to prove out a possible
root cause.
BASIC TROUBLESHOOTING
46. THE BASIC TROUBLESHOOTING
STRATEGY
REPAIR
FIX IT!!!
• Once a definite root cause is
discovered, steps need to be
taken to temporarily or
permanently repair the machine.
• WD prints can be re-referenced
to locate specific sensors or valves.
BASIC TROUBLESHOOTING
47. THE BASIC TROUBLESHOOTING
STRATEGY
DOCUMENTATION
Words for the Ages
• Something often overlooked in the
troubleshooting process is
documentation.
• Not only does this help other personnel
who may also be troubleshooting that
piece of equipment, it will also help YOU
when two years have gone by and you
completely forget about a problem.
BASIC TROUBLESHOOTING
48. THE BASIC TROUBLESHOOTING
STRATEGY
The Basic Troubleshooting Strategy will:
• Make your troubleshooting more
effective.
• Eliminate duplicate troubleshooting
(Same problem appearing on different
shifts)
• Reduce Downtime due to more effective
repair of malfunctions.
BASIC TROUBLESHOOTING
49. THE BASIC TROUBLESHOOTING
STRATEGY
• List three examples of Sensory Input
• Filtering input is a way for you to
discover the _______ _______
of the problem.
• What is the final step in the Basic
Troubleshooting Strategy?
BASIC TROUBLESHOOTING
50. THE BASIC TROUBLESHOOTING TOOLS
DRAWINGS
The work area drawing depicts a dedicated area
of the plant comprised of;
• machinery
• control equipment
• personnel
This area implements
the manufacturing
process of a specific
Component(s)
BASIC TROUBLESHOOTING
51. THE BASIC TROUBLESHOOTING TOOLS
DRAWINGS
Depending on the process, this
machinery may consist of
various pieces of
equipment.
Each executes a
programmed sequence
of operation that puts
the part(s) through various
stages of the production
Process.
BASIC TROUBLESHOOTING
52. THE BASIC TROUBLESHOOTING TOOLS
DRAWINGS
Area Drawings can be
used to Locate equipment
and controls.
Suggestions;
• Make notes on drawings
for reference.
• Identify control device
locations
BASIC TROUBLESHOOTING
53. THE BASIC TROUBLESHOOTING TOOLS
DRAWINGS
Drawings can also indicate the
various control devices,
associated sensor devices,
and their tag names.
These tag names can be
searched and cross referenced
in the working drawings,
tag database, the ladder logic,
and the HMI I/O status display.
BASIC TROUBLESHOOTING
54. THE BASIC TROUBLESHOOTING TOOLS
DRAWINGS
Device Drawings can provide
The following data;
• Tag Name
• Node Address
• Wire Labels / Numbers
• Contact Data (NO or NC)
BASIC TROUBLESHOOTING
55. THE BASIC TROUBLESHOOTING TOOLS
SEQUENCE OF OPERATION Station 25W Widget Assembler
• Details the sequence of a •
•
Operator places Widget Part W21 on conveyor
Widget Part W21 moves into assemble
position, pin clamps open.
given machine or process. • Widget Part W21 part present #1 and #2 detected.
• Widget Part W24 travels to Assemble position
above Widget Part W21
• Can be used to identify the •
•
Pin Clamps close on Robot Widget Part W21
The assemble process starts
• The W-frame press starts down over Widget
area of malfunction. Part W21 and Widget Part W24
• W-Frame (Press) continues down and stops
(dwell time).
• Problem is usually in the step •
•
The clamps extend.
W-Welder Robot spot welds Widget Part W21 and
Widget Part W24
just before the uncompleted • The W-frame press starts up from Widget Part W21
and Widget Part W24
step. • The clamps retract
• Widget Part W-25 ( combined W21 & W24) moves
on to conveyor
• Widget Part W-25 clears fixture
• Next sequence begins
BASIC TROUBLESHOOTING
56. THE BASIC TROUBLESHOOTING TOOLS
HMI SCREENS
The Human Machine Interface (HMI)
is used to communicate with the
control system of the machines.
BASIC TROUBLESHOOTING
57. THE BASIC TROUBLESHOOTING TOOLS
HMI SCREENS
The Human Machine Interface (HMI)
is used to communicate with the
control system of the machines.
HMI devices are used to;
• Check the operation status of a
Machine.
• Permit operator to modify
operation.
• Provide alarms and warnings
BASIC TROUBLESHOOTING
58. THE BASIC TROUBLESHOOTING TOOLS
HMI SCREENS
Typical HMI Screen
• Display a system
status.
• A form of this
screen is located
on almost all
machine HMI’s.
BASIC TROUBLESHOOTING
59. THE BASIC TROUBLESHOOTING TOOLS
HMI SCREENS
• Displays are
typically color
coded (red and
Green) to indicate
normal or fault /
alarm status.
• Notice how the
Man/Auto Ready
indicator shows
Auto not ready,
along with the
system local
message. BASIC TROUBLESHOOTING
60. THE BASIC TROUBLESHOOTING TOOLS
HMI SCREENS
An example of an Alarm
Display to view system
faults.
• Every message has a
event number that is
related to a Message
Event in the controller
logic.
BASIC TROUBLESHOOTING
61. THE BASIC TROUBLESHOOTING TOOLS
TRACING LADDER LOGIC
ONLY TRAINED INDIVIDUALS SHOULD
ACCESS THE LADDER LOGIC.
• Tracing Ladder logic in the controller
requires specialized training in the
particular software used by the controller
unit.
• Possible machine damage and personnel
injury can result from un-authorized
modification to the controller logic.
BASIC TROUBLESHOOTING
62. THE BASIC TROUBLESHOOTING TOOLS
TRACING LADDER LOGIC
A trained individual can
use a Controller Work Remote
Run
station or a computer
loaded with specific
software to;
• View the ladder logic
program executing in
the controller.
• Modify logic
• Override some signals
for diagnostics
BASIC TROUBLESHOOTING
63. THE BASIC TROUBLESHOOTING TOOLS
TRACING LADDER LOGIC
An example of a Rung of
Ladder Logic.
• An input signal or
output signal can be
viewed in real time by
accessing the ladder
logic of the controller
unit.
BASIC TROUBLESHOOTING
64. THE BASIC TROUBLESHOOTING TOOLS
TRACING LADDER LOGIC
• Tracing a signal in the
logic requires good
documentation of the
various controller logic
elements.
• An input signal or
output signal can be
viewed in real time.
• Specific Signals can
be modified (forced) to
aid in diagnostics.
BASIC TROUBLESHOOTING
65. THE BASIC TROUBLESHOOTING TOOLS
CONTROLLER SYSTEM INDICATORS
• Controller Systems
usually have Status
Indicators located on
the Controller and
modules.
• Using the indicator
LEDs and the Manufacturer
manual one can get a clue
as to the malfunction
BASIC TROUBLESHOOTING
66. THE BASIC TROUBLESHOOTING TOOLS
CONTROLLER SYSTEM INDICATORS
• Controller Systems usually have
Status indicators located on the
Controller and modules.
• Using the indicator LEDs and the
Manufacturer manual one can
Get a clue as to the malfunction
BASIC TROUBLESHOOTING
67. THE BASIC TROUBLESHOOTING TOOLS
CONTROLLER SYSTEM INDICATORS
Example : 1756-L55 Controller Module
Status Indicator Descriptions
RUN - Indicates mode of operation:
Solid Green – Processor is running
(reading inputs, executing logic, and
writing output data to enabled output modules)
Off – Processor is not controlling outputs
(processor could be in program mode,
test mode, or no power)
BASIC TROUBLESHOOTING
68. THE BASIC TROUBLESHOOTING TOOLS
CONTROLLER SYSTEM INDICATORS
I/O - Indicates status of configured input and output
modules communication:
Solid Green – Processor is communicating to its
configured input and output modules
Flashing Green – One or more, but not all,
configured I/O modules is not communicating
Flashing Red – No I/O modules are
communicating or the processor has faulted
Off – No configured modules
BASIC TROUBLESHOOTING
69. THE BASIC TROUBLESHOOTING TOOLS
CONTROLLER SYSTEM INDICATORS
FORCE - Indicates the presence and status of
forced I/O:
Off – No forces exist in controller
Flashing Yellow – Forces installed, but not active
Solid Yellow – Forces installed and active
RS232 – Communications activity of serial port
Flashing Green – Data is being sent or received
through the serial port
BAT – Status of memory backup battery:
Solid Red – Battery Level low and needs
to be replaced
Off – Battery is OK, or no power
BASIC TROUBLESHOOTING
70. THE BASIC TROUBLESHOOTING TOOLS
CONTROLLER SYSTEM INDICATORS
OK – Status of Controller module:
Green – Controller is OK
Off – No power applied
Flashing Red – Minor or major recoverable fault
Solid Red – Major non-recoverable controller
fault; must be corrected and reset
BASIC TROUBLESHOOTING
71. THE BASIC TROUBLESHOOTING TOOLS
MANUFACTURER MANUALS
• Equipment manufacturers often
times include a troubleshooting
section in the machine manuals.
• Check the manuals for hints on
detecting and preventing
malfunctions
BASIC TROUBLESHOOTING
72. THE BASIC TROUBLESHOOTING TOOLS
MANUFACTURER MANUALS
• All have different styles.
(See this example) Excellent
source of information specific
to the machine.
• Some provide flowchart style data
BASIC TROUBLESHOOTING
73. THE BASIC TROUBLESHOOTING TOOLS
MANUFACTURER MANUALS
Type Code Fault Description Recovery
1 1 The controller pow ered on in Run mode. Execute the pow er-loss handler.
3 16 A required I/O module connection failed. Check that the I/O module is in the chassis.
• Others provide error Check electronic keying requirements.
View the controller properties Major Fault tab
and the module properties Connection tab for
code data. 3
3
20
23
Possible problem w ith the ControlBus chassis.
At least one required connection w as not
more information about the fault.
Not recoverable - replace the chassis.
Wait for the controller I/O light to turn green
(See AB Controller 4 16
established before going to Run mode.
Unknow n instruction encountered.
before changing to Run mode.
Remove the unknow n instruction. This probably
happened due to a program conversion
example) 4 20 Array subscript too big, control structure .POS or
process.
Adjust the value to be w ithin the valid range.
.LEN is invalid. Don’t exceed the array size or go beyond
dimensions defined.
4 21 Control structure .LEN or .POS < 0. Adjust the value so it is > 0.
• Use the manuals to
4 31 The parameters of the JSR instruction do not Pass the appropriate number of parameters. If
match those of the associated SBR or RET too many parameters are passed, the extra
instruction. ones are ignored w ithout any error.
4 34 A timer instruction has a negative preset or Fix the program to not load a negative value into
interrupt sensory 4 42
accumulated value.
JMP to a label that did not exist or w as deleted.
timer preset or accumulated value.
Correct the JMP target or add the missing label.
data. 4 82 A sequential function chart (SFC) called a
subroutine and the subroutine tried to jump back to
the calling SFC. Occurs w hen the SFC uses either
Remove the jump back to the calling SFC.
a JSR or FOR instruction to call the subroutine.
4 83 The data tested w as not inside the required limits. Modify value to be w ithin limits.
4 84 Stack overflow . Reduce the subroutine nesting levels or the
number of parameters passed.
4 89 In a SFR instruction, the target routine does not Correct the SFR target or add the missing step.
contain the target step.
6 1 Task w atchdog expired. User task has not Increase the task w atchdog, shorten the
completed in specified period of time. execution time, make the priority of this task
“higher,” simplify higher priority tasks, or move
some code to another controller.
BASIC TROUBLESHOOTING
74. THE BASIC TROUBLESHOOTING TOOLS
MAINTENANCE LOGS
• Maintaining accurate records of System performance
parameters of each machine will make problem
Identification and malfunction troubleshooting much easier.
• The sooner you identify potential problems will result
reduced downtime.
BASIC TROUBLESHOOTING
75. THE BASIC TROUBLESHOOTING TOOLS
MAINTENANCE LOGS
• Early detection can be achieved by recording a
“baseline” of selective parameters such as
voltages and average readings for each major device
and periodically checking for deterioration.
• The baseline data would ideally be collected at
the installation of the system once all of the bugs
have been worked out. In the event that this data
was not collected at installation time, data
collected when the system is functioning correctly
can be used for the baseline information.
BASIC TROUBLESHOOTING
76. THE BASIC TROUBLESHOOTING TOOLS
MAINTENANCE LOGS
• Once the baseline data is established, periodic
checks of the actual network data can be
compared to the baseline and potential
malfunctions addressed prior to becoming
shutdown situations.
• The next slide an example of a Baseline data form.
This is only an example. You may wish to develop
your own based on;
• Your experience with the network
• Operation of particular systems
• Certain types of devices
BASIC TROUBLESHOOTING
78. THE BASIC TROUBLESHOOTING TOOLS
Troubleshooting Worksheet
MAINTENANCE LOGS
Fill in the form to help you keep track of your troubleshooting effort. Exercise #
Check ‘Yes’ in each box if it applies. Team # Another example of a Log
Start with observation.
Questions Yes No Findings
Is power on?
Is the machine cycling?
Does the cell appear to have stopped mid-cycle?
Is there a fault message on the ‘Bingo’ board?
Notice that this example
Are there any fault lights, a fault message, or horn? Follows the Basic
Is it a hardware fault or operational fault?
Are there any unusual sounds?
Has the operator offered any information?
Troubleshooting Strategy
Are there any other unusual things happening? • Sensory Input
Determine where to find the cause. Narrowing your focus.
Questions What area are you going to focus on?
Are you going to review more PV+ screens?
Yes No Findings
• Filter
Are you going to look at more indicator lights?
Examine the tooling / fixture?
Are you going to view the teach pendant screens?
Are you going to look at weld controller screens?
• Action
Are you going to try to cycle in manual?
Are you going to look at the ladder logic?
Do you need a multi-meter or net-meter?
Other (specify):
BASIC TROUBLESHOOTING
ACTION I understand what happened. Now I determine what to do about it.
79. THE BASIC TROUBLESHOOTING TOOLS
MAINTENANCE LOGS
REPAIR Fix the problem and verify that it works.
Yes No Findings
Basic Troubleshooting
Questions
Were you able to fix the problem? Strategy
Is the line now in Automatic and ready to
run?
• Repair
Do you feel that the root cause was fixed?
• Documentation
DOCUMENTATION Finishing the effort by documenting your findings for others
• Adds Section for
Yes No Findings
Questions
Is there a logbook to fill out on this line? your Comments and
Was it necessary to update files after the suggestions
repair?
Were the prints updated and valid?
Did you find logic rungs that should be
commented better?
BASIC TROUBLESHOOTING
80. THE BASIC TROUBLESHOOTING
STRATEGY
• What would you check to determine
the next step in an operation or process?
• What should you check to determine the
Controller Systems is functioning
Correctly?
• What would you use to determine if the
malfunction had occurred previously?
• What would you put on a Log for the
machine you are responsible to
maintain?
BASIC TROUBLESHOOTING
81. THE BASIC TROUBLESHOOTING
Review
GAMBLERS
• Relies completely on random chance to find the problem!
• Logical sequence not followed!
• Forgets what already has been tested!
• Tends to waste time and effort!
• Checks everything in the system!
• Lack schematic interpretation and component
diagnostic skills!
• Reconfigures the system to provide new information!
• Very dangerous to both equipment and personnel!
• Likes to experiment with components within a system!
• Must use extreme care not to introduce new faults!
BASIC TROUBLESHOOTING
82. THE BASIC TROUBLESHOOTING
Review
GAMBLERS
• Rely on knowledge of common fault occurrences!
• Bet on what they think is the correct solution based
on symptoms they recognize!
• Troubleshooting requires an increasing level of skill!
• Can be very efficient!
• Can quickly get the equipment functioning!
• Exhibits risk-taking behavior!
BASIC TROUBLESHOOTING
83. THE BASIC TROUBLESHOOTING
Review
TESTERS
• Likes to look, listen, touch, and smell!
• Valuable strategy for obtaining important information!
• Rarely a stand-alone problem solving method!
• Generally use schematics/prints!
• Performs voltage checks, continuity checks, or signal tracing!
• Start at a known good point in the system and work
toward the fault!
• Start from a faulty symptom and search backward to
the error’s source!
• Depends heavily on good test equipment and
schematic/print reading skills!
BASIC TROUBLESHOOTING
84. THE BASIC TROUBLESHOOTING
Review
TESTERS
• Divide & Conquer!
• Half split method!
• Successive approximation!
• Divide a system or circuit in half and check for proper
readings, then continue to divide and check!
• Use jumper wires
• Disconnect portions of a system or circuit!
• May contribute to confusion because of the induced
interaction of components!
• Potential for damage to equipment or injury to personnel!
BASIC TROUBLESHOOTING
85. THE BASIC TROUBLESHOOTING
Review
THINKERS
• Least skilled form of the “Thinking” approach!
• Highly recommended in many situations!
• Instances still arise to troubleshoot manually!
• Must be able to switch to another style of troubleshooting!
• Rely more on their memory of symptoms and solutions
from many years of experience!
• Troubleshooting needs continual practice!
• Tend to lose troubleshooting skills!
• Solve common problems in familiar systems!
BASIC TROUBLESHOOTING
86. THE BASIC TROUBLESHOOTING
Review
THINKERS
• Use theoretical knowledge to evaluate faults!
• Rarely efficient!
• Highly skilled troubleshooters!
• Use system knowledge and observations (sight) of
symptoms to eliminate portions of a system in a logical
way!
• Requires a detailed understanding of the system!
• Think before you approach!
• Relies on FUNCTIONAL SEARCH STRATEGIES
BASIC TROUBLESHOOTING
87. THE BASIC TROUBLESHOOTING
Review
DRAWINGS
• The work area drawing depicts a dedicated area
of the plant comprised of; machinery , control equipment,
and Personnel
• Area Drawings can be used to Locate equipment and
controls.
• Drawings can also indicate the various control devices,
associated sensor devices, and their tag names
BASIC TROUBLESHOOTING
88. THE BASIC TROUBLESHOOTING
Review
SEQUENCE OF OPERATION
• Details the sequence of a given machine or process.
• Can be used to identify the area of malfunction.
• Problem is usually in the step just before the uncompleted
step.
BASIC TROUBLESHOOTING
89. THE BASIC TROUBLESHOOTING
Review
HMI SCREENS
• The Human Machine Interface (HMI) is used to
communicate with the control system of the machines.
• HMI devices are used to; Check the operation status of a
Machine, Permit operator to modify operation, and
Provide alarms and warnings
• Displays are typically color coded (red and Green) to
indicate normal or fault / alarm status.
BASIC TROUBLESHOOTING
90. THE BASIC TROUBLESHOOTING
Review
Trace Ladder Logic
ONLY TRAINED INDIVIDUALS SHOULD ACCESS THE
LADDER LOGIC.
• Tracing Ladder logic in the controller requires specialized
training in the particular software used by the controller
unit.
• Possible machine damage and personnel injury can result
from un-authorized modification to the controller logic.
• Use a Controller Work station or a computer loaded with
specific software to; View the ladder logic program,
modify logic, or Override some signals for diagnostics
BASIC TROUBLESHOOTING
91. THE BASIC TROUBLESHOOTING
Review
CONTROLLER SYSTEM INDICATORS
• Controller Systems usually have Status indicators located
on the
Controller and modules.
• Using the indicator LEDs and the Manufacturer manual
one can
Get a clue as to the malfunction
BASIC TROUBLESHOOTING
92. THE BASIC TROUBLESHOOTING
Review
MANUFACTURER MANUALS
• Equipment manufacturers often times include a
troubleshooting
section in the machine manuals.
• Check the manuals for hints on detecting and preventing
malfunctions
• Manuals provide error code data.
BASIC TROUBLESHOOTING
93. THE BASIC TROUBLESHOOTING
Conclusion Module One
Using the Basic Troubleshooting Strategy improve
Your troubleshooting ability and result in:
• Increased production
• Reduced down
• Confident Workforce
BASIC TROUBLESHOOTING
94. THE BASIC TROUBLESHOOTING
Conclusion Module One
Thank you for your attention.
Keep this process in mind
during the second Module
When we will address specific
Machines on your plant floor.
BASIC TROUBLESHOOTING