PLCs...

[paul]

Re: PLCs...

You can really grasp how much we benefit from PLC's after you open up an old elevator relay cabinet. All those relays can be replaced by a few lines of code.

 

[physis]

Re: PLCs...

I've only worked with Allen Bradley Modules a couple times and didn't get to program any. That's always disappointed me a little. I was looking for the first guy to mention ladder logic. Unless I missed someone it was Bryan.

From what you said Bryan it sounds like a pretty low level language. (The lower the level the closer to machine code). I've heard of guys that had a lot of problems with it and others that had no trouble.

 

[paul]

Re: PLCs...

Physis,

Ladder logic is also known as relay logic. Not any different that what you would use for figuring out how to wire a motor control system.

 

[friebel]

Re: PLCs...

I am an instructor at Delaware Technical & Community College in the State of Delaware.
One of the courses that I teach is PLC's(programmable logic controllers). I am teaching the Allen-Bradley SLC 500 PLC.
I want to point out to all of the aspiring electricians out their the importance of learning the basic rudiments of PLC's.
One of my students informed me that he had a resume with a company that trys to get employment for applicants. The student informed me that he had a couple of "hits" for employment. Upon taking the PLC course, he updated his resume, to include the PLC course that he was taking.
He received 18 hits within a two week period.
So, you can see the importance of having a basic understanding of PLC's on your resume.

 

[Ed MacLaren]

Re: PLCs...

It has been my experience, from years of teaching PLC Basics, that the guys that were already familiar with relay logic, that is, those who had already completed our motor control courses, found the PLC courses much easier to understand.

Most PLC principles can be introduced using "mechanical" analogies. For example, I used the city street and house number analogy to introduce the concept of I/O addressing and memory locations.

The most difficult "adjustment" seemed to be how to get the guys to stop thinking of the "Examine ON" and "Examine OFF" instructions as actual NO and NC contacts.
I wish the originators of ladder logic had used different symbols for these basic instructions.

Ed

[ December 18, 2004, 08:57 AM: Message edited by: Ed MacLaren ]

 

[petersonra]

Re: PLCs...

One thing that is often helpful in instructing students on RLL is to explain them as ands and ors. Most kids have some basic boolean algebra somewhere along the way (whether they know it or not).

 

[rattus]

Re: PLCs...

For Midget: I think you should plan for an ASET, that is Associate of Science in Engineering Technology. With some guidance, you can plan out a program that will prepare you for employment as an engineering technician including programming.

Meanwhile, you need to learn about binary number systems before you tackle Boolean algebra.

The ASET is a two year program; the BSET is a four year program; the BSEE is a five year program. Take your pick.