I am begginer ,how to proceed with projects.

Q1. What is the difference between plc and microprocessor

Q2 Which software is used to write programs for plc.If possible give examples.

Q3 Can u give real world example how plc works with any system.

Q4 How can I elobrate the information give on net into practical basis
Q5 How can I get plc simulator on my pc.give me a link.

Thanks

Nimish said:

Q1. What is the difference between plc and microprocessor

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The heart of a PLC is a microprocessor.

Nimish said:

Q2 Which software is used to write programs for plc.If possible give examples.

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Propriarty software: STEP5 for the Siemens S5 PLCs, STEP 7 for the Siemens S7-300/400 PLCs, S7MicroWIN for the Siemens S7-200 PLCs, RSLogix5 for Allen-Bradley PLC5, RSLogix500 for Allen-Bradley SLC500 PLCs, RSLogix5000 for Allen-Bradley CompactLogix and ControlLogix, CX Programmer for Omron PLCs, and so on. The list is as long as (in fact even longer than) the list of PLC manufacturers.

Nimish said:

Q3 Can u give real world example how plc works with any system.

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Nope. This question would take me way to long to answer. The best answer is to click the 'Learn PLCs' link at the top of the page.

Nimish said:

Q4 How can I elobrate the information give on net into practical basis

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By three simple words: practice, practice and practice. It gets better over the years, but beleive me: you're never done learning. It has taken me over 26 years by now and I have learned the most valuable lesson there is: you're never done learning.

Nimish said:

Q5 How can I get plc simulator on my pc.give me a link.

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I have no clue. The PLC simulator her on PLCs.net is strictly an on-line simulator. There are others around. One of the finest is the LogixPro one at the LearningPit, but it isn't free.

Kind regards,

Hi I am green on the topic too, but I found very useful starting from "small" PLC's like ZElIO (telemechanique) or LOGO. I prefer Zelio to tell you the truth. I bought a Zelio PLC which was a pack with the supporting software. I found it quite enlightening. This software includes also a simulator which makes programming quite fun. It also includes quite good notes on how to use the zelio soft

I am not sure but you might even find the software (zeliosoft) through internet. If you can pinpoint to me the way I might be able to send you the software and some notes I have (lets hope they are not in Greek...). I know how it seems at the beginning abyss isn't it. It is Fun though.

Learning to program plc's

I sympathize with you. I have found that the best way for a beginner to learn is to learn by doing. Have you ever been to Ebay? Goto Ebay and look around for machine controls, plcs, and pneumatic components. For less than $500 you can biuld a very good simulator that acts more like the real world.

You might end up with a couple of inverters, a couple of gearmotors, 5 or 6 pneumatic valves, an encoder and some photo switches and proximity switches. Get you some chain and sprockets. Use pillow block bearings.

To biuld a carraige that is postioned by an encoder all I did was to take a 3 ft long piece of gear rack and mounted some cam rolls on the sides so that the rack teeth were pointing up. Get a small electric motor and mount a spur gear onto it and mount the motor where the gear moves the rack back and forth. Mount the encoder next to this with it's own spur gear. Make sure that the gear on the encoder has a small amount of clearance between teeth so as not to strain shaft on encoder but only a small backlash. The cam rolls on the rack move on a piece of cold rolled steel mounted to a good work benck. Put an inexpensive microswitch on either end to stop travel.

Put a small shaft bteen two pillow block bearings so that you can you have a chain on either side driven by the motor. This gives you two chains. Put some dogs on the chain or go to a motion supply place and buy some conveyor chain links that have dogs on them. This way you can put proximity switches to read the dogs. You can use these to simulate conveyors and carriages. You can also take small motors and control these with small 24vdc relays. On Ebay you can sometimes buy this sort of thing cheap. Get a gear and put it on the motor and count teeth.

With your air cylinders you can use two proximity switches to measure forward and reverse. Just tap a small pc of steel and put it on the end of the rod for the prox to pick up on.

In your control cabinet put plenty of teminals end (cheap on ebay) so that hooking things up is easy. Put a few toggle switches in your control panel and plenty of pushbuttons. I goto the junkyard a lot too. Get a good big contol box so you'll have plenty of room to add and change things.

etc, etc, ect.

The point in all of this is that it's not boring when you are learning plcs this way because you actually are watching something that is moving. I am working on a panel saw right now and I may have to convert it over to a plc. With the simulator that I built I can simulate the whole panel saw. One chain with a dog on it represents the saw carriage which moves back and forth to make a cut. One air cylinder represents the hold down beam, one air cylinder represents the saw movement up and down, and the pusher is represented by the rack and pinion. This whole machine is easily simulated. My simulator is on a steel workbench that is on rollers so I can roll it where I need it. The control box is also on rollers. My first simulator was nothin but indicator lights. I was bored before I got started.

Put a good 3 foot machinist scale or tape rule next to the rack and drill a hole and put a pointer on it so that you can see how far it moves. I got a brake for my motor from Grainger and it stops right on the money. With this whole rig you can easily teach yourself all of the commands with a little thought and you'll be having fun as well if your just starting out. In saying all of this I assume that you have some electrical knowledge. Remember electricity kills. It can start a fire in a second.

If you've got a small workshop you will be surprised at what you can build with a small metal saw, a drill press, and a vise and files. A few handtools, files, drill bits, and taps. I have a small machine shop so it was no problem for me but I'm telling you it can be done with the small tools and what you'll learn you won't ever forget and you won't get bored. Just check out what PLC training costs. What I'm giving you is not unrealistic and is doable. Even if you spend a $1000 it's well worth it. However, you'll be surprised at what you can scrape up on ebay and at a good junk yard or manufacturer's auction. Good Luck!

helluvawreck

reg plc

sir,
i'm happy to inform u that i have some resource.if possible i can send u, plz tell me the way u can access it.
regards
ram

hellovawreck is right get a cheap used plc and software from ebay it doesnt matter what make as long as you get software because this can be very expensive personally i think mitsubishi is far easier than siemens and allen bradley but thats just my opinion.

When youve got the kit have a play start simple ie turn on input 1 output 1, then insert a timer to delay output 1, or a counter, or maybe get the output to flash at 1 sec intervals, just write very short code until you are happy with the way it works and unlike hellovawrecks advice i would use simple switches as inputs and lamps as outputs to get you started quicker and more cheaply.

when youve started writing code and have a problem come here and describe clearly what you want to achieve let us know what type of plc and software you are using and im sure plenty of people will help

finally can i say in my opinion its not worth asking questions until youve tried hands on with a plc, its like asking for advice on how to drive a car when youve only ever seen one in a magazine

I also agree with davefinic. At the very beginning of learning all I used was the output leds on the plc alone and wrote simple programs to get the feel. However, I became bored with this after a while and needed to be motivated by the other so at some point I believe many people will want to watch things move in a more realistic setting. BTW, I still consider myself a beginner and I never will stop learning. With me I use this stuff in my work at the plant but the only way to become a pro is to work under a pro and get on the job training. Being in the manufacturing business I was unable to work under a trained technician so what I know I had to teach myself. I know that I missed out on a lot of good training. I was forced to get envolved with it because machines break down but I also like it as well as machine work. Anyways, good luck with your learning.

helluvawreck

helluvawreck i agree a test rig is great but with no disrespect to nimish his questions are very basic and im sure he would be happy to see a light sequence that he has programmed.

I myself just use lights and switches on my simple test panel i might not be the sharpest knife in the drawer but i can imagine a cylinder moving forward or a motor starting when a light comes on

im not charging anyone for building my test rig so i save the serious work for when somebody else is paying

Mistsubishi book

Nimish, I used to trade on Ebay all the time and bought a lot of stuff for our plant. I have been on ebay but once lately so it may have changed. However, used Mistubishi's used to turn up frequently as well as some good deals on the new ones. A few years back the company Mistubishi even use to sell some plcs. I bought a number of these plcs from Mitsubishi and with each plc I got the Mistubishi software on cd. As a matter of fact I have 8 never used cd's that I legally own. It's older software but is marked FX-WIN - 1, version 3.00. I'm not sure what this software contains. I later bought from Mitsubishi their medium package because I thought that I might need their support. If Mistsubishi still sells on ebay they might still include the software with a plc and this would be a good deal. Also, Mistsubishi use to give you their software package if you buy a PLC from them from a dealer. This is exactly the reason I still use Mistubishi PLC's because I didn't have to buy the software. This is probably a good sales tool for Mitsubishi to get people to start using theior PLC's. I don't know enough to say where Mitsubishi's fit in in quality etc. However, they have always been good for me.

If you go with the Mitsubishi to start with look up the following book "Mitsubishi FX Programmable Logic Controllers, Aplications and Programming by John Ridley. It's published by Elsevier. It's not the deepest book on PLC's but it is specific about the Mitsubishi and can be helpful for a beginner. It's also modestly priced.

I think what we use is GX developer FX. The first copy I got was free a few years back for buying a PLC. I don't know if they still do this. Remember, I'm certainly not a pro so I'm just telling you what I know - one beginner to another you might say. I hope it is helpful.

helluvawreck

test rig

Dave, here's the thing though. You are probably a professional. I'm not a professional and I just own a manufacturing business with my brother. A lot of people just starting out with this sort of thing are just like me, I believe. They don't have any formal training so they don't know a prox switch from a photo switch. Now I'm a little further along with this, now. However, when your just starting out it helps to play around with prox switches, photo switches, relays, etc. especially when you can get them so cheap or even free at a junk yard. Lights don't really show you how to set these up and trouble shoot them. Naurally, a professional has formal training and is comfortable with all of this stuff and takes a lot for granted.

The way I started out was about 30 years ago I made it a point to watch everything an electrician or technician did when they came into our plant. I didn't know anything. I asked a lot of dumb questions. I did this for about 2 years, then I just started troubleshooting the stuff myself. It was a little clumbsy at first but I got better and better at it. Then I started building control cabinets on my own to replace worn out controls or for something that I built. I learned about electrical controls by using them. I would have given anything for the formal training but I didn't have time to go to school because of the business.

I'm not trying to put myself off as much more than a beginner. i went to machinist school for 6 months but i quit because I had a family and the instructer wouldn't let me make parts for a machine that I wanted to build. I talked the company into buying a horizontal bandsaw, a welding machine, a drill press, a cutting torch, and a Bridgeport Mill and I started to build stuff for our plant. I've been doing it now for 25 years or so but i know I'm not a machinist and missed out on a lot of good training. We've added to our shop quite a bit. However, I have learned a lot and 90% of it was by messing with the real thing.

Anyways, I understand completely what your saying and respect your point of view as well. Nothing is better than on the job training under a professional such as yourself but some people who use plc's are not able to work under a professional or get formal training. But they still want to use plc's in their business; also, the only way they are going to be able to do anything with controls is to build stuff with them and experiment.

There's probably two types of groups that want to learn PLC's and controls. Those who want to make a living as technicians and those who want to use them as a hobby or in their business. The latter group will never get the formal or on the job training that the first group does, therefore the latter group had better take a very hands on approach or they will never get anywhere.

helluvawreck

heluvawreck i think its great that youve learnt so much without any formal training. i have had good training full apprenticship and lots of good courses (some real bad ones too) but i still find its good to learn from just having a go if you learn the hard way youre more likely to remember than sitting in a class and just being told or shown, i run my own company now and have to find answers to problems every day sometimes if the guys that work for me ring in with a question i may know the answer but then again i may not, still i have to find an answer whereas they just pass the problem on to me. every time we get into something new i make the effort to learn at least as much as them even though they are working with it day in day out. were never through learning in this game which makes it all the more interesting.

professional technicians

Dave, I can't tell you how much I respect a professionally trained technician that really knows his stuff. It sounds like you are just such a technician. My favorite machinist friend was just such a fellow. He had come up through the ranks as a machinist in the Navy and then went to work for Caterpillar and started from scratch and went through their training and then worked as a professional for them then on into tool and die. He ended up in his 30 by 30 shop with just the basic machine tools and built special machines for people occasionally. That's just the way he loved it - a one man shop. I never saw a man that could do more with just the basic machine tools than he could. I never got to see him too much but when I did he never minded answering some of the dumb questions I would ask him. I would have loved to have been able to work under him for a few years but it just weren't meant to be.

My hat is off to people like you and him.

helluvawreck

hey, dave. I've got a dumb question for you. I noticed that you are from UK. You are obviously a trained and seasoned technician and also have your own business. I assume that you would know and understand the following question:

Because of my lack of formal training I do not know all of the modern electrical symbols for electrical blueprints, especially the european ones.

Whenever I build a control box I try my best to do a good neat job. In our plant we have a lot of modern equipment so I have been able to pick up some things from going through the blueprints for these machines. I can usually figure out how to find my way around and figure out what's going on for the most part in these machines.

Whenever I build a control panel I try to do a good engineering drawing for the controls. However, they are certainly not what I would call professional modern control drawings but are sort of a hodgepoge of things that I have picked up over my years of messing around.

i have used autocad light and also the simplified version of Turbocad to try to make my control drawings nice and neat (again a hodge poge of symbols not quite up to par). I understand my drawings well enough but I have always wanted to improve on them and use the right symbols.

Is there a place where I can goto to that shows the modern EU symbols and what they all mean? It seems like the Europeans are further along on this sort of thing than we are.

We are mostly in the archetectural moulding business and many of our machines are manufactured by a company called Weinig from Germany. They are high tech for this industry and use all of the modern methods. They make very neat control cabinets. Most of our machinery is European. I have learned a lot about control cabinets just spending time to see what they have used to build their cabinets with and studying their blueprints.

Where would somebody like me goto on the internet to get some good solid information about modern control symbols for electrical drawings?

helluvawreck

modern control cabinets

Hey, Dave. I've got another dumb question:

We all know there are places to goto on the internet to learn about PLC's.

Is there a place to goto to just learn about all of the modern methods to build modern control cabinets? If there are I would love to know these URL's.

Do you know of any?

Thanks

helluvawreck