Question on Learning

Hi All,

I've been reading this forum for a while now and I just want to thank you for everything I have learned...some things, I have no clue what you are talking about, but hopefully I will sometime.

I work for a company in which I am in charge of the electronics of our plant as well as some electrical. I have started learning AB RSLogix and I understand it somewhat. I don't know all the commands but I can write a program that will do what I want it to do (make be a few extra rungs, but all is good). I have RSLogix 500 and Emulate installed on my computer here at the house. (I don't want to learn 5000 yet until I have a good grasp on 500) Also installed I have DeviceNet and ControlNet. I want to know what are good sources to learn these two packages. I have viewed alot of programs that have them, and I am not quite sure how to use it in my programs.

Eventually I want to get into the automation business. My Dad has been in this business for 18+ years now. Before I can go to work for him I have to finish my AAS degree in Electrical/Electronics and have 5+ years of field experince. As of now, I have 6 months experience. I came out of the computer programming field into this great field, and I must say I love it. Should've of gone into it to begin with!

Thanks for any help you all give me. I look foward to talking with you all more in the near future.

Here are a couple of DeviceNet sites



http://www.odva.org/

http://www.koldwater.com/

Greetings Lionel,

my simple advice is to get your hands on some “real world” hardware as soon as possible ... the “emulator” software is ok for a start ... but nothing beats wiring up inputs and outputs and learning how the whole system fits together ... one suggestion: since your father works in this trade, coming up with some “scrap” hardware shouldn’t be too hard to do ... remember (for example) that if one or two outputs are “blown” on a module, the rest of the outputs might still work just fine for “experimenting” in the lab ... e-bay is another source of reasonably priced hardware ...

another good thing to do: try to dissect some “real-world” programs and figure out exactly how they work ... if you run into something that you don’t understand, consider posting the troublesome sections on this forum ... the guys here will be glad to give you a hand ... just make sure that you’re not posting any “proprietary-super-secret” stuff from one of your father’s customers, etc. ...

final suggestion (for now): get yourself some of those cardboard “archive” storage boxes from an office supply house ... reason: do not use the trash can for your “scrap” notepaper from now on ... instead, drop the “scraps” into one of these storage boxes ... when the first box gets full, store it in the attic and start filling up a new box ... you’ll be surprised how often you’ll find yourself shuffling through these old “I’ll-never-need-this-junk-again” notes ... the more experience you gain, the more you’ll start to recognize that a LOT of this stuff falls into repeating patterns ... do the same with your old PLC program files ... don’t throw them out ... instead zip them up and salt them away (on something more trustworthy than a computer hard drive) ... you’ll be surprised how handy this stuff will come in down the road ...

good luck ... keep us posted on your progress ... let us know how we can help ... and welcome aboard ...

PS edit ... make friends with your local distributor ... most of them have complimentary (free) "show and tell" seminars from time-to-time ... sure they're basically a "sales pitch" but they often involve some "hands-on" exercises and demonstrations which can be a good way to gain some extra experience for free ...

Ron,

Thanks for all the information and advice! I do want to get a PLC for my own personal use so I can actually see what is going on. My Dad is going to try to help me out with that part. I also want to get a 110 motor and such so I can actually hook up items here and learn with them.

I have a test board at work but I don't get much time to spend with it so I need one here that I can do before I go to work. My Dad sent me about seven of his programs for me to look at, I understand a lot more then I did at the start. I might have to post some things I have questions about.

This board is full of information and plenty of people who know their stuff. I look foward to learning. But for now, off for another wonderful day of work. (You have to love 2nd shift!)

First major Project!

Well I finally got my first major project at work. It is nothing that has to be done right now. They have been trying to do this for 3 years and well, still nothing.

I am going to draw up some plans and let you guys look at them and give me some feedback. All this has to do is turn a package 90 degrees counter clockwise. My biggest thing will be getting it to keep up with the speed of the machine, but I have an idea on how to do it.

What would you all suggest would be a good PLC to get? I've been looking on eBay and there are someout there, I just want suggestions on which to use.

well if your looking to completely study all of the AB instructions I would look for an SLC 503 or better. although micrologix 1200 and up would be more affordable.

I am leaning towards the 503 since I can learn the entire instruction set with it and we mainly have that in the plant. I know it is going to cost a little more but thats the price we pay to learn.

I am also looking for different things to hook up to it so I can see it run. I was looking at getting a control cabinet but dag, those things are expensive.

I acquired mine from an old machine that no longer is in use.

Sounds like you are on the right track to get started well. Please keep us up to date on your project - sounds like it is probably a good one.

But beware...two statements you made make me wonder...

They have been trying to do this for 3 years and well, still nothing.

Click to expand...

and

All this has to do is turn a package 90 degrees counter clockwise.

Click to expand...

Make me think that there is a whole lot they haven't told you yet.

If I were taking this on, some of the first stops I would make would be with the machine operators to find out what all REALLY needs to happen, and then with anybody and everybody who has had anything to do with the attempts over the last 3 years. Something kept those efforts from being a success. I would definitely want to know what that was.

In short, be a detective, do your leg work, and don't be afraid to look stupid. No one will remember how you looked in the beginning, especially when you accomplish something others have been unable to.

Steve

I am sure there is a little they have not told me. The person who was in charge of it just never really made a try at it either. It has been something they have wanted to do, but just haven't got around to it. Being on 2nd shift I have a little time to do it (also helps that this machine does not run on my shift).

Also no one really has any PLC experience at the plant. They always hire someone to come in. I want to take over that if possible (save the company money so maybe the can pay me more )

The project is this:

Packages some out of the machine long ways onto a conv. that feeds the scale/pre price system. For the correct placement of the pre price label and bottom label it has to be rotated 90 degrees clockwise. Tonight I will draw up a diagram showing what I mean. I hope to have some ideas down also so you all can critize it and give me any possible pointers.

But for now, I am heading home ... err work... I swear I spend way to much time at work.

Is there a mechanism in place to turn the packages that nobody has been able to make work? Is it appropriate for the type of packages that your have to turn? Do you know why it doesn't work?

Before you try to write a PLC program to control the machine, make sure that the machine is capable of doing the job. You may be able to overcome some of the shortcomings of bad mechanical design by clever programming, but only up to a point. Furthermore, by taking on the task, you assume ownership. When the project ultimately fails, all anyone remembers is that the control system didn't work. They overlook the fact that the mechanical design was inadequate.

Hi Lionel!
Welcome to your new adventure! Steve brings up some interesting questions (inquiring minds want to know), but in addition to those....I have a few also.
1. Dimensions and weight of product
2. Dimensions and weight of turntable or positioning device
3. Method of actuation; motor-driven, pneumatic or hydraulic cylinders, chain, belt, etc...
4. Speed of process
Just want to make sure that your load doesn't exceed the output capacity of the PLC. You'll probably need at least a couple of relays between the PLC and the load and some sort of positioning feedback. I hope I'm not overstating the obvious, but you mentioned that you're new at this.

You may also be able to do this job with a popup conveyer that feeds one direction exits another. If its a live roller conveyer there are some tricks for positioning that you can do with the rollers themselves. not a 90 degree shift but if you can shift it 15 degrees then having the rollers mounted on an angle can correct your positioning without any additional controls. This is usually called scewing of the rollers

I'm familiar with that set-up too Mordrid and it works well if you have enough space.

I apologize for the misspelling Mordred!