# PLCs for Beginners



## CoreyOnTheBrink (Apr 9, 2021)

Hey all. I was wondering if anyone had recommendations for resources about PLC operation and programming? I know YouTube is a great resource, but does anyone have any specific channel that they would recommend? It stinks getting 5-10 minutes into a YouTube video and then realizing that it sucks. Or maybe an online class? I'm looking to learn the basics, especially the programming.


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## wiz1997 (Mar 30, 2021)

Have you looked into any classes at a local college or community College?
I took my first classes at a local college as continuing education classes.
No credits earned.
Years later I took the college level classes which really wasn't any different from the first classes I took.
This time I got the credits towards my Associates in Electrical Technology.
Unless you already have some type of field related degree, most employers are looking for PLC related education and experience.

Something I left out, was perhaps taking a motor control class first would be beneficial to get a basic understanding of motors and drives.


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## splatz (May 23, 2015)

I would highly recommend "PLC Programming for Industrial Automation" by Kevin Collins, it's a great introductory textbook and it's well suited to self-study. 









PLC Programming for Industrial Automation: Kevin Collins: 9781846855986: Amazon.com: Books


PLC Programming for Industrial Automation [Kevin Collins] on Amazon.com. *FREE* shipping on qualifying offers. PLC Programming for Industrial Automation



www.amazon.com


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## bill39 (Sep 4, 2009)

Get involved on this website: PLC talk.net/quanda

It’s free, people are helpful, and there is a free trainer to use. You can ask homework questions but won’t do it for you.


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## Wardenclyffe (Jan 11, 2019)

RSlogix 5000 student manual and troubleshooting guide.


I have an rslogix 5000 student manual and troubleshooting guide I no longer need! the student manual has a loose page but its still there and has a bit of dirt from being in my tool locker. and the troubleshooting guide is in good condition. If anyone is interested in them, They are free I just...




www.electriciantalk.com


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## SWDweller (Dec 9, 2020)

Have you discovered that there is two general ways of programing PLC's?
Ladder logic, and Function Block. 
Depending on where you live you will use one or the other. I live and worked in the western US and ladder was what I learned. Where as some of my friends and co workers knew function block.
I my humble opinion check on line and buy one. 4 inputs and 4 outputs is enough to get started.
Learning the communication from the PLC to say you laptop is critical. You might check with you local Eaton, Siemens, or GE reps. They might have one that you could use for some time.
I know that Eaton's PLC,s are made by Toshiba and brand labeled to Eaton.
The type is less important IMO than knowing how to start and end a program 
The memory registers for timers and counters is very important to know how to use. 
Where you live may have a lot to do with what every one uses. 
The ABB rep pissed me off so I bought 30 grand of PLC parts and pieces from Omron. They sent the instruction manuals in either Japanese or Chinese. Either way I could not program it. So I called up the inside man and politely asked for English manuals. I was told I should have asked for English now i would have to pay for them. I then left a message for the sales man and when he called I told him what had happened. He agreed that the manuals were extra. I said because only one box had been opened the next time he stopped by he could pic all of it up. We would be returning the order. 2 weeks later we got the manuals in English. 
I have used 4-5 different manufactures of PLC's. All I need is a manual with the memory locations and I can get started programing. 

if you looking for a challenge write the code for a 4 way traffic signal with a leading turn arrow of 40 seconds before green. Have fun.

Now the rub. Some of the older PLC's communicate on Serial ports. Worse some only work with true DOS. Not a DOS emulator like what is in Windoze now days. My work laptop was a dual boot with Win95 and NT 4.0. Be sure to check the specs. 
Have fun it is I believe a rewarding skill to learn


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## bill39 (Sep 4, 2009)

CoreyOntheBrink:
Please don’t be offended but here is an important point- Are you quite well versed in hard-wired relay logic? This goes a long way in properly wiring the I/O points, creating drawings, as well as programming for failsafe conditions.


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## paulengr (Oct 8, 2017)

Most PLCs these days are converging towards IEC languages. In the US I’d say in large plants AB has about 85% of the market. Outside of those Koyo (Automation Direct) is extremely popular. Everything else is hit or miss. Support with the first two is quite good. But for example it took 4-1/2 years after reporting a bug before GE fixed it and in North Carolina there is just about one contract programmer in the entire state for Siemens and zero factory support.

In terms of the PLCs themselves as an example the Automation Direct Click PLCs come with free software and the PLC itself is $50-200 depending on model. All you need extra is a 24 VDC power supply and a $20’programmjng cable. The documentation and training on their web site is free. In contrast with AB the cable is now USB. The software is $6500 plus you pay 20% of that per year for support (first year is free). PLCs start at $1500. Get the idea? With AB you can always find better but you’ll never pay more.

In terms of programming languages I’d say 90% of it is ladder logic. It’s the one most easily understood by electricians and instrument engineers. In some parts of Europe Instruction List that looks like machine language is popular. Structured Text which some PLCs support is Pascal. It is popular with computer programmers but very difficult to troubleshoot so everyone else hates it. Finally function block is basically the old DCS system. It works best for control loops (analog) but it’s not very popular. Most PLCs don’t support it. You pay extra for the software with AB. There are also all kinds of mini languages in every PLC and tons of idioms and ways of doing things. For instance I swear every PLC out there has its own unique way of doing timers and almost no two are alike. IEC has standardized the way programs are organized...sort of. Remote I/O is always a treat to program...which means it’s always some funky unique syntax.

But beyond this there are certain algorithms and ways of doing things that work better than others. Well written and organized code is a thing of beauty. That is where you get into programming theory and where most PLC programmers fail. For instance many PLC programmers wrote code for a sequence of steps using a method called onion logic. It is highly error prone, difficult to troubleshoot, and difficult to work on. Another method called state machines is very easy to write and troubleshoot, very robust, and just plain better. That being said in 30 years I’ve only seen 3 or 4 programmers use state machines.

Still I’d say 90% of PLC programs have or should have less than 50 lines of code. There are only so many ways to write code for conveyor sequencers. Very few involve analog and of those few do closed loop control. So you can go a long way with “smart relay” programming before you get more advanced and by then you’ll be looking at programs written by others as examples.


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## CoreyOnTheBrink (Apr 9, 2021)

Wow guys. Thanks for all the information! To answer a couple of questions, I didn't know that there were so many different programming languages that could be used. The only one that I have heard people refer to is the ladder logic. It does seem like a good idea, if I were to pursue this, to just take a college course or two. I'm not sure what the "well-versed" level of relay logic would be, but I can read and write a wiring diagram and build control cabinets from them. I just built a cabinet for day tank fuel controls based on a design someone had in their head. So I think I could probably make the leap into an introduction to PLCs. I do lack a little bit in theory and also I'm not naturally mechanically inclined; that's something that I've had to train and teach myself.

It's a little overwhelming and I'm not sure I'll dive into this world, but when it comes to electrical work I have just loved control circuitry, both design and assembly. It also seems really valuable and something most electricians know little about. Anyway, this all seems like a trade in and of itself and I wonder how much research and development it would take to actually be able to gain the skills to use in the market. I do not work for an employer that installs or maintains or programs PLCs, but I think it would be fun and challenging one day to market myself as such and perform those services. I've seen a few guys that are self-taught just because they were fascinated by them and it quickly formed into a time-consuming hobby. Now if I could just kick my two and four year olds out of my house already maybe I could take on that hobby.


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## SWDweller (Dec 9, 2020)

I have worked for a slew of contactors in my career. 3 come to mind that had people who could work on PLC's and those guys did not get paid much more than the rest of the pack. Unless your doing startup for a vendor the odds are the skill will not be needed. I was pushed into learning because of working for a University in Arizona. Some body bought a new sprinkler control/pump sled and it did not work very well. The problem was nobody realized that this machine got is power from a 440v 3 phase transformer, (not a misprint) The controller was set for 480V. We all know how important foot ball is to a students education. 
It is exacting and interesting work, I would not have wanted a steady diet of it.


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## Bahd (May 26, 2020)

Check out TheLearningPit - PLC Simulators and Resources for Training. There is a bunch of free tutorials on there along with a download link for a 15-day trial of LogixPro. Which is a basic version of Rockwell's RSLogix500. Should give you a good foundation to start with the basics of ladder logic.


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