New PLC programmer requesting help :)

Hello all!
I am completely new to PLC programming, and I am SURE that I will have even more questions for this forum before I am done. I have not even had a chance to get my hands on the hardware that I will be working with, but my question/dilemma is this: A friend wants me to do some PLC programming for him at his shop, and the person who he used to have doing it for him just up and left with all of the programs/documentation etc, so he has nothing except for the hardware with the PLC instructions in it. My first question is, how does one usually retrieve the PLC program from the hardware? Is there a certain software program that I need to do it? What sort of cabling is usually necessary? Once I retrieve it as a text file, I can then begin looking at it and try to make sense of it. I also understand that I will be using 'registers' which correspond to an action that the machine would take (ie move conveyor belt, move arm, etc)....how will I know which registers correspond to what without any documentation from the previous programmer? Thanks for your help on this, and thanks in advannce for your future help!

Lugosi,

Although I commend you on your ambition, I strongly suggest that you visit www.thelearningpit.com and read and study all the material there, and buy Phil's book and read and study that. THEN, if you still think this is what you want to do, come back here and ask away. I don't mean to put you down in any way, but I really think you need to spend a little time and become just a bit more informed.

Good Luck !!!

Jim

You sound like you might be a PC programmer who's just seen his first PLC. If that's the case, you've got experience that will help because you can "think" like a machine. But, PLCs are very different from PCs. You're probably going to experience some culture shock.

Some tips related to your post:

1. You won't (usually) be able to just download the PLC program to a text file. You need the programming software and communication drivers for the PLC brand and type you are looking at. Then, you can go online and grab the program if the processor isn't locked.

2. Download is a relative term. Most of us consider a download to be INTO the PLC.

3. Cables depend on the PLC.

4. When you manage to get at the program, you probably won't get any documentation. Most documentation is saved in the original program file on your PC. We're all looking forward to the day that changes! It is going to take time and patience to interpret the code without documentation.

Welcome to the forum!

AK

Thanks so much for the replies. Well, color me a bit disheartened, but I still want to go about trying to learn a little, even if I wont be able to take on the project. He doesnt have forever and a day for this to get done, and it is gonna take me quite a long time to learn what I am seeing on these very helpful sites that you folks led me to. It all sounds very interesting, and it could be fun once I learn what I am doing.

What brand of PLC and where are you located? Someone here may be close by.

The only thing that I know for sure is that it is an Allen Bradley, but I have no clue as to model # or anything like that.

Lugosi
You might want to check out the website on Allen Bradley PLC products. browse around and you will find the model you will be working on. Hope it helps.

regards
Sherine T.

I would try some "social" engineering first, ie. find the dude and get back the company property

Harry

That fish of an avatar you got there; now that really fits what you have stated.bonkhead

I would try some "social" engineering first, ie. find the dude and get back the company property

Click to expand...

Woah...scary harry fish.lolis