What now ?

HoldenC

Member
H
Join Date
Sep 2012
Location
Cumberland, KY
Posts
220
In the past couple of weeks I have been able to read the Beginner, Intermediate, and Electrical books from this website. They helped a lot. Also in the meantime I installed LogixPro on my pc and have been working my way through them simulations. I got the program from my PLC class i took while in college a few years ago.

My questions now is, what would you suggest I do now ? Other books to read, or software to practice with ?

I will admit first that I understood the Beginner and Electrical books right off. Now the intermediate book still has a few parts that are still giving me problems understanding. However, I am reading over it a 2nd time right now.

I thought about getting a copy of the ladder logic from my job site and and going over it at home and maybe learning how things work there. Would this be a good idea ?
 
Find out what Brand of PLC your job site is using, then get the programming and installation manuals for that Brand(s). There may be items used that you have not yet seen.

How are you going to look at the logic? Programming software is best, but it costs. Looking at a pdf file can be done, but how will you get a printout?

Make sure your employer is OK with you having a copy of some sort.
 
before you take a copy of the plc program at home, i suggest you ask your boss first and get permission. some companies won't mind your learning the program at home and showing initiative while others will look down on it, you are stealing company information.

regards,
james
 
One of the things i was having trouble with was the PID loops. I know my work places uses these because It was a big deal when we put them in the logic a couple years ago.

The place i work at actually hired me to learn their PLC set-up, along with some other stuff. Networking, warehouse management, electrician, ect. So, its no problem for them to get me a copy of logic software.

They are totally fine with me making copies of the ladder logic.

I know we use AB PLC-5's and AB SLC-500's. The SLC-500s were added when upgrades were done.

Thats where im a little confused as well. Since there are multiple PLC's spread out on the property that are all connected together, could i get all the ladder logic from one of them? Or, would I need to visit everyone of them ?
 
Every PLC has its own program so you would need access toeach one.
if your factory PLC's are networked then you need to be carefull.
as far as getting copies of the programs there will be copies on a PC with 'Tags' it is very easy to erase these by accident - not a good thing.

As Far as PID
Think of a bouncing ball the first bounce is to one height the next is lower then lower and lower etc.
when you have a hot cup of coffee and it is too hot. how much cold (water/milk) do you put in it
similar to the bouncing ball.
so a PID can be set for how often to check temperature how long to apply heat or cold etc.

this is only a very rough explanation
 
Thanks so much for the help.

Could you explain the "tags" thing. Maybe you could explain the best way to download the ladder logic and not mess anything up.

Im thinking the ladder logic files are stored on a pc for backup. I may be able to just make a copy of that.

I think I understand the basics of a PID loop. Im going to see if I can find some videos on programming one as well.
 
I don't know any of your background, but I would look at the processes I was going to be working with and be sure to have solid knowledge and experience troubleshooting mechanically what is going on.

In my opinion the total understanding of the mechanics of the machine and principals of operation, i.e. hydraulics, pneumatics, electrical circuits, etc., is mandatory before modifying a running PLC program or writing a PLC program.

Dave
 
Maybe you could explain the best way to download the ladder logic and not mess anything up.
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The best way would be to get the person (that maintains backup copies of the plant PLC programs) to make you paper print-outs of the ladder logic programs (or print PDF copies to a thumb drive). Then you don't risk making a bad mistake while trying to copy the files, and you can watch and learn how to do it at your site.

If you have no such person, then we can go from there and find the next-best alternative.

Note that with these ladder logic copies, you will not be able to use these to go online with a PLC or modify a program in any way. I think that will be best at this point in your training.
 
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I would really like to just look at the ladder logic and see how things are configured.

I think this will be my next step. Ill look around for copies stored on the computer.

By the way, what type of file extension should i be looking for ?

What is the average file size in a coal preparation plant ? I know they must vary wildly, but should it fit on a 16GB flash drive, correct ?
 
By the way, what type of file extension should i be looking for ?
Click to expand...
I would look for *.PDF files in the folders used for storing backups. With PDF files, you can view or print out with the Adobe Acrobat Reader. If there are no PDF files, then you will need to get someone to run the PLC software programs to create PDF files (by printing a "report" of the ladder logic to a PDF file.
 
Hi

.rss for the slc .rsp for the logix 5 and . Acd if you have any 5000

If you need them converted to PDF and you ate aloud post them here you will get them converted fit you

Keep on looking and learning I am this game 10 plus years and I learn everyday and ask loads of questions never lose that

Donnchadh
 
One thing I learned in my many years of technical work is "If you want to really know how something works, try changing it." So, if you have anybody there willing to help, have them print-out the logic for a particular function and then challenge you to develop, on paper, some modification. It will be a challenge.
 
in some PLC's Tags or Symbols and or descriptions / lables etc. are only kept in the prrogram on your PC or notebook
once you erase this or copy over it with a blank file you loose that info.
eg.
Input 1.0 = stop button
if this is copied over all you would see is
1.0
 
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