PLC TRAINING OVERVIEW

PLC Training by Business Industrial Network 11/02/2014
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This presentation is designed to give you the basics of what a PLC is, and why you
should know. This PLC training PowerPoint is from 1 hour Webinar BIN95.com
president put on for the Association for Facilities Engineering (AFE.org).
Pictured here is what a PLC looks like. It’s a small square computing device that
controls machines and has a bunch of LED lights. Next time you ride an elevator, sit
at a traffic light, or use the water faucet, think about the fact that a PLC, or PLC like
device is controlling it. Next time you look at all the machines in a manufacturing
plant, know that each one probably has a PLC in it controlling that machine, being
the brains of the operation.
Copyright 2014 by www.bin95.com

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Business Industrial Network www.BIN95.com

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It’s best to first learn what a PLC is to better understand why all of maintenance,
and engineering should know these basics of what a PLC is. ☺
PLC and lighting control – On or off, it is as simple as that.
Technology evolution – Smaller and faster in a nut shell
PLC control cycle – Who’s in control now?
PLC Programming – What to look for.
PLC/Automation management – Save money you didn't even know you where
losing.
Why train all maintenance & engineering? – And at what levels?

Everything in the PLC is 1s and 0s, on and off, etc. , like switches that are on or off.
A lot about the PLC and working with it can be simplified to that same level… 1 or
0, on or off, true or false. In this 1 hour webinar, we will be keeping it to its most
simplest form. We could go on about that “PLC” stands for Programmable Logic
Controller and all, but everyone refers to them as PLC, so for this webinar purpose,
you do not need to memorize acronyms. As long as when we are done, if someone
mentions “PLC” to you, you know what they are talking about.
Copyright 2014 by www.bin95.com 4

Person in control uses Sense of sight to determine room is dark, so turns on light.
The person’s eye is a sensor input, and their brain the controller making the
decision, and their finger output action of flipping on light.

But the smart sensor is very limited in decisions it can make, unlike the human
doing the same job. Also important to note, if we wanted to add conditions, it would
take hard wiring and possible replacement of sensor/control to modify control. So
greater time and cost will result than if a PLC was used to control light.

The PLC, just like the human …
1. Looks at inputs for sensors, then …
2. Makes a decision based on preset conditions it is programmed to look for, then
…
3. Tells the output to energize and turn on the light.
After
step 3 above, it restarts the 3 steps over, in a continuous cycle (loop). This is called
a scan cycle.
Scan cycle = Scan inputs, process ladder logic, update outputs. Then repeat in a
continuous loop.
The advantages of a PLC over a human? The PLC frees up human time, and is more
reliable. Equally advantageous is when process changes or is improved. No
rewiring, and retraining of all humans in a building, manufacturing plant or
society.

It started out as hard wiring Relays which made modifying circuits/control costly,
and the electro-mechanical relay + wiring was less reliable. The PLC was
specifically designed to reduce relays, wiring and cost while providing more
reliable and flexible control. The PLC was also specifically designed to be as simple
as possible for electricians to work with, so its designer’s adapted electrical
diagrams as the programming language called Ladder Logic.
About 10 years ago the PLC evolved into a PAC (Process Automation Controller).
The PAC has many differences between them and a PLC, with the most notable
being scan cycle and audience designed for. The PLC scans rungs in sequence and
can only work on each of the 3 task, one task at a time. The PAC multi-task, update
I/O simultaneously as it has multiple processors instead of just one micro-processor
like the PLC has. But even more monumental than multi-tasking is the fact the PAC
was designed for the IT/Computer programming audience, instead of electricians.

Scan Cycle = Inputs, Ladder Logic, Outputs (repeat)
Inputs: There are basically 4 types of inputs to a PLC. There is discrete (1 or 0, on or off),
analog (varying voltage or current), special and communications. Examples of discrete
inputs are push buttons, limit switches, proximity sensors, etc. An examples of an analog
input is a thermal couple that measures temperature. A special module example might be a
high speed counter module you wire an encoder to that measures linier distance and speed.
Communication modules are both inputs and outputs, sending and receiving data from
another device external to the PLC.
Ladder Logic: Is an electrical schematic used as the programming language of choice for a
PLC. You will see rungs (electrical circuits) of logic on the computer software you use to
access the PLC. Ladder logic is a blend of Boolean logic (1 and 0s language) and electrical
schematic. One rung of logic can be interpreted as Boolean using key operands “IF”,
“AND”, “OR”, “THEN”.
[IF darkness is sensed AND motion is detected, THEN output to light.] “IF” starts new
rung, “AND” and “OR” are conditions to be met, with “THEN” indicating output if rung
conditions are met.
Outputs: Outputs come in basically 4 types also, discrete, analog, special and
communications. Outputs most commonly are discrete and wired to an external relay to
drive greater current or voltage than the PLC is capable of internally. An analog output
example is outputting a 0-10 volt signal proportional to the speed you want a motor to go.

The PLC 5 is the full size (regular) PLC series. (Item numbers like PLC 5/40, 5/20.
5/15 etc.)
The SLC 500 is the “Small” series. (Item numbers like SLC 5/01, 5/02, 5/03, 5/04,
and 5/05)
The Micrologix is the smallest of all three legacy series. (The micro 1000 being the
least expensive and smallest.)
The PLC on the far right is the ControlLogix from the new series Allen Bradley
came out with. The one shown is the full size of that new series. They then have a
small PLC daubed “CompactLogix” and a very inexpensive FlexLogix in the new
AB series of PLCs.

SLC 5/01 This processor offers a basic set of 51 instructions with the choice
of 1K or 4K of memory in a modular hardware configuration. Modular I/O
systems that include a SLC 5/01 processor can be configured with a maximum of
three chassis (30 total slots) and from 4 I/O points to a maximum of 3940 I/O points.
SLC 5/02 This processor offers additional complex instructions, enhanced
communications, faster scan times than the SLC 5/01, and extensive
diagnostics that allow it to function in more complex applications.
SLC 5/03 This processor provides 8 K, 16 K, or 32 K of memory. A built-in RS-
232 channel gives you the flexibility to connect to external intelligent devices
without the need for additional modules.
SLC 5/04 The standard DH-485 port has been replaced with a DH+ port,
providing high-speed SLC 5/04-to-SLC 5/04 communications and direct
connection to PLC-5 controllers.
The available memory options are 16 K, 32 K, or 64 K. In addition, there is an
SLC 5/04P option, which is designed specifically for the Plastics Industry and
contains ERC2 algorithms for Plastics Machinery Control.
SLC 5/05 The SLC 5/05 processor provides the same functionality as the SLC 5/04
processor with standard Ethernet communications rather than DH+
communications. Ethernet communication occurs at 10 Mbps or 100 Mbps,
providing a high performance network for program upload/download, online editing,
and peer-to-peer messaging.

When you plug into a PLC with a computer and open the PLC vendor’s software, a
screen similar to the one above is what you will see. On the left is a project tree
which is files and folders like on your computer, but these all have to do with the
PLC. On the right is the programming language, in this case Ladder Logic. The
example pictured also has some key elements to best practices. Discripted
subroutines, more than one subroutine, descriptions on all elements (contacts/coils)
and supporting documentation like symbols/tags and rung descriptions.
If the “DARK” contact (element) and the “MOTION” contact are highlighted green,
the PLC will highlight green with the output “LIGHT_ON”. This allows the PLC to
turn on the light in the real world.

Of course Safety and Reliability are a given, but keep in mind there is usually room
to make it more safe and reliable. The more experience, training, and exposure to
other professional’s methods you have, the more likely you will see areas for
improvement. So it requires a continuous learning and improvement program.
Make sure the PLCs and PACs are primarily programmed in Ladder Logic so your
electricians and in-house staff can understand them. Alternate programming
languages should only be used if necessary to meet control expectations. Like with
a PAC, the equipment designers have 5 programming languages to chose from. If
the OEM chose to use structured text programming language, the people working
with the machine may not be trained in IT or computer programming, which will
drive up your total cost of ownership over the life cycle to possibly many times the
original purchase. So it is well worth getting your maintenance trained enough to
spot a lack of best practices, and have them involved in the purchasing process of
equipment with a PLC/PAC in it.
The quickest way for one to learn more about PLC programming, and learn industry
standards is to study existing working programs.

But it doesn’t matter if you have 5 PLCs or 50, the odds are mishandling and
mismanagement of your PLCs will negatively impact your operation and possibly
bottom line. I have written much on this topic, and you can get more detailed advice
in the article at http://bin95.com/maintenance_management_plc.htm
http://bin95.com/maintenance_management_plc.htm
For this short webinar, if I had to narrow it down to just three takeaways, they
would be …
•Inventory all your company’s PLCs (spreadsheet to help in article above.)
•Train all of your maintenance and engineers (Who will be working with PLC
controlled equipment)
•Develop PLC policies and procedures. (SOP/ISO level would be nice, but some
is better than none in this case.)

Besides protecting a company’s bottom line, technology keeps evolving, and so
should a company’s employees with the aid of proper PLC training. Notice the
slide do not read “Why educate …” , it reads “”Why train …” While PLC education
is always helpful, to reduce a company’s risk, its pesonel should be trained as well.
That is trained in working with PLCs and automation safely, reliably, and using best
practices.
Worse case scenario for a company, they only have one employee who is their “PLC
Guru”. An all your eggs in one basket situation. We recommend as a minimum 1
PLC Technician per shift, 1 from engineering department, and the maintenance
manager. (As a minimum) Typically companies who don’t have the minimum, lose
in downtime cost what it would cost for training or even an additional employee.
PLC Training should meet our standards (http://bin95.com/plc_training.htm)
covering not only scholastic knowledge, but real world practice application that
focuses on Safety, Reliability and best practices. Just getting by with one training
software, video course, seminar, book, or self taught should not acceptable for those
who have to work with PLCs. The ultimate solution should be a holistic, and all of
the above approach. (As time and money permit after considering reduced
downtime savings and increased reliability value.)

Many believe you complete one PLC training software program, or take one online
PLC course, or video course, and they’ll be ready to hit the ground running,
troubleshooting, and modifying PLC programs in a machine or system that may cost
thousands, or millions of dollars, with potential risk to man or machine. From the
chart on this slide you can see that can’t be further from the truth if you want to
remove most of that unnecessary risk. Believe it or not, some are out there taking
that risk, and are only self taught. (They don’t know what they don’t know.☺ )
First, one should have the prerequisites of being trained in industrial electrical
basics, and be computer literate. Then the next part of training should be the Safety,
Reliability and Best practices foundations (Currently only taught by bin95.com and
colleges we taught), which reduce the bulk of risk to man or machine. Then after
establishing a good foundation to build on, then it is time to add the scholastic
knowledge (books, video courses, basic software, etc.). From there you move on to
acquiring the PLC troubleshooting experience, which could take years, or you could
supplement that troubleshooting experience by using the training software at
BIN95.com. Then the PLC tech needs to get experience on 2 or more PLC brands.
That’s the basics of PLC training, then a person is ready to move on to advanced
topics like PLC programming, communications, the PAC, and more computer
training in prep for HMI and SCADA.
The chart on this slide has guides based on job titles, and experiences. Based on
your experiences, and your PLC related responsibilities, different levels of training
are needed.
You can download, and view full size chart at
https://www.flickr.com/photos/manufacturing/15734663012/

As you might have already known, the most effective PLC training is on-site,
followed by hands-on seminars, with instructor based delivery methods. Then those
training delivery methods are followed by online courses, video course, and training
software, depending on the quality and approach of each. As on-site PLC training
comes at a higher cost, and with instructor live on-site, time can be a limitation.
That is why our approach is to first deliver the most important core foundation via
instructor based on-site training, or training seminar. For more time consuming
scholastic part of knowledge delivery, other delivery methods can be used more cost
effectively, if building on the core foundation mentioned previously.
Hopefully by now you are starting to realize no one single method is the total
solution. It takes blended learning to cost effectively become a PLC expert working
with PLCs safely, reliably, and using best practices.
(http://bin95.blogspot.com/2012/02/path-to-plc-expertise.html)
You can view a larger size chart at http://bin95.com/Why_onsite_training.htm

Extra slides follow this one should there be extra time today, and for you to review
on your own time later. Several of the slides also mention extra learning links for
resources that support the respective slide’s topic. Also remember when attending
BIN95.com seminars or requesting a quote for on-site PLC training, that AFE
members get 10% discount if they let us know they’re a member.
I recommend everyone check out 3 free on-line PLC related courses on bottom of
page http://bin95.com/university/ as part of their continuing education.
Advice: If a person is saying, “I already had PLC training”, or “I have been working
with PLCs for over 10 years, I don’t need additional training”. Ask yourself or
them…
In the previous PLC training? …
How many tips on reducing downtime did the instructor give you?
How many times did instructor give you advice on how to work safely with PLCs
that was not in the PLC manual’s safety installation tips?
How many ways to work with PLCs more reliably did the instructor pass along?
How many best practices did you get instructed on? (Typically manuals only cover
wiring and installation best practices, not best practices in programming, working
with PLCs, or in managing them within your facility).
Most will answer “none” to all of the above. For the few who do remember a few,
but not details… its time for a refresher, or your annual PLC training. ☺

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This slide and the following slides are excerpts from our instructor based PLC
training, shown here for additional information….
During BIN95.com instructor based PLC training, the above recommendations
where emphasized. They are listed here as an reminder and for future reference.

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The methods we have chosen are based on experience over many years, and within
many industries. Not only are the methods taught in this class, highly recommended
to reduce risk, but will also give you more confidence while working with PLCs,
knowing you have a quick way to recover from most mistakes.
You may notice some redundancy in the methods taught. Please note, this is to
emphasize the more important methods while overcoming lesser efficient methods,
and habits that may have been picked up from being self taught.

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As mentioned earlier, in all windows type programs, there are several ways to
perform the same task. Most tasks are accessible via “Toolbars” as this is found to
be the easiest to remember. Individuals may better associate a picture icon with the
word related to the task to be performed.
The Search Tool (Find Instruction, Address/Symbol) is probably the most
important, and most used tool. You can type in an input address, or the associated
symbol (tag) for that input, and press enter. The display will go to the first rung
found with that input. Then you can check for status, or monitor for change. The
same search tool can be used with all types of contacts, and descriptions.
Example: XIC I:2.0/2 with a symbol of “PE2” and a description of “TOP KNIFE
WIDE LOAD PRESENT”
This can be found by typing in …
“I:2/2” or “PE2” or “KNIFE” (Note: there is only one contact with address I:2/2 or
symbol “PE2”, but there may be many different contacts with “KNIFE” in their
description.)
Also important note: You see a red “x” on “Confirm Edit Tools” to remind you
never use that worst practice. (As explained why in our instructor based PLC
training.) With vendor PLC training, most college instructors, videos on YouTube
(other than ours at bin952 channel), and most other PLC training providers, you will
see them use and instruct you to use the “Confirm Edit Tools” without ever
mentioning, or knowing to tell you “to never use these two toolbar buttons”, as it is
worst practices and can cause huge amount of downtime. Even worse, the user of
these two tool bar buttons will never know that is what caused them the downtime.
So they will most likely never learn not to, unless they receive http://bin95.com
instructor based PLC training, where a lot more best practices are taught.

The cable selection chart shown organizes the various cables used to access Allen
Bradley’s PLC 5, SLC 500 series, and their Micrologix controller. The DH+ and
Ethernet columns show cable choices if you want to view and access PLCs that are
networked together. The Data Highway Plus is a secure industrial network. The
Ethernet would be a less secure network common to computer networks.
The RJ485 and RS232 columns have cables that would be your second choice if
your PLC does not have DH+ or Ethernet connection capabilities. RJ485 is a
standard industrial communication protocol while RS232 is standard to computers.
If a company’s laptop does not have a 9 pin serial port (RS232) on it or a PCMCIA
to RS232 Port Replicator, you will need to use an additional cable to convert from
USB to RS232. Converting from USB is the least desired of all connections, as
there will be more to the set up of software and more possibilities for
communication driver conflicts. If you have to use a USB to RS232 converter, go
with Allen Bradley’s UIC cable or PLCCables.com cable.

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IMPORTANT! Click the Normal Protection Control button if you want to
reuse the EEPROM Memory module.
When you select “Store to EEPROM”, a dialog box will pop up, giving your two
options to select from. Normal Protection, allows you to re-burn the EEPROM in
the future if changes are made to the program. This is the default selection and
should always be the one you choose.
Write Only Protection, will prevent any future burning of the EEPROM, thus you
will not have a way to save any future changes to the program. DO NOT SELECT
THIS OPTION.
Remember how in class the instructor showed you how to use EEPROM to have
zero downtime from one of the most common causes.

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This is another slide from bin95.com instructor based PLC training with tips, notes,
and terminology as a reminder to what was covered in the workshop.
Load Memory Module On Memory Error S:1/10
Upon cycling of power to the processor, if a memory error is detected in the RAM,
the backup copy in EPROM will be automatically loaded into RAM and the
processor will be placed back in REM RUN.
So with S:1/10 bit set and EEPROM program copy kept current, your customer can
have a normal operation with error from voltage spike going undetected and zero
downtime.
* Additional Note: Currently flash memory stick is the most stable offering
possible, as it cannot scratch like a CD, it cannot be de-magnetized like a floppy
disk, and is overall, fairly indestructible.

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The instructor will show you in the actual RSLogix software, several real life
program examples while explaining troubleshooting and how common instructions
work. We will start with elements being highlighted, to show their “True” or “False”
state. The Examine if Closed (XIC-’normally open contact’) and Examine if Open
(XIO- ’normally close contact’) will be discussed. Moving on to timers, counters,
and compare statements. This part of the class varies greatly depending on the
classes experience level and questions.

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Another slide from our instructor based course
you won’t see in other’s PLC courses, or in PLC
training delivered via other medias…
***** SAFETY *****
BUSINESS INDUSTRIAL NETWORK DOES NOT PROMOTE THE USE OF
FORCES!
The difference between “forcing” a bit and “toggling” a bit is …
When you “Force” a bit on or off, it over rides what condition the ladder logic is
calling for and all failsafe the programmer designed in the logic.
When you “Toggle” a bit, the very next scan cycle, the ladder logic is read and the
bit is returned to the condition the ladder logic is calling for.
So even though we toggle bits in class for demonstration and simulation purposes,
in the real world with a running PLC, toggling a bit does not affect the machine in
most cases. (because within one scan cycle, the bit’s original value is restored.)

This is a PAC. It looks like a PLC, but the important differences between a PLC and
PAC are critical to know before working with one. Many do not know, surprisingly
many other companies, and colleges delivering PAC training don’t even emphasize
the difference to students.
In short, the Process Automation Controller (PAC) is an Advanced PLC. More
accurately it is structured like a computer and has a PLC built inside it as just one of
the many functions. To learn more see http://bin95.com/PLC-PAC-Difference.htm

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We also put extra slides in our on-site, and seminar powerpoints so attendees can
continue to learn after instructor based training time has ran out. Like this slide…
PLC - Program Logic Controller Used to control equipment.
Symbol – A word that can be assigned to and be used in the place of an Address.
(Example: Can type in a search field or edit field; S:1/15 or you can type
“1st_scan_bit”. Both would be inter-replaceable.)
Note: Rung descriptions, element descriptors, symbols, page titles, etc. are not
saved inside the PLC. They are saved in the copy of the program on your computer
only.
PE - Photo Eye

PLC TRAINING OVERVIEW

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