An Application example for me to teach PLC

I guess that I should tell you the same thing that I would tell one of your students who wanted me to do their homework for them.
And that is: Show me what you have and I will be happy to comment on it.

As with all classes of this type, you need to decide what your main focus is. Are you trying to teach logic development, how to use and get familiar with the programming environment or both?

The biggest problem you will have is that any process that would logically use all the programming methods you list will be too involved to comprehend in a day. The students will spend all their time figuring out the process and none of it learning how to enter code unless you have already broken the process down and tell the students what functions they need to put in each format.

Having said that, a multi-station 'machining' center with variable tool feedrate and feed force could logically use all the programming formats you listed. But, again, you would need to break apart the process for them if you want them to get the code entered in a day.

Keith

The applications I worked earlier are too complex to be taught in a one day session.

Click to expand...

does this mean that you only have ONE day for the training? ... yikes! ...



but anyway, my favorite way of handling the problem is to take one semi-simple programming project and then work through the program in all four of the programming methods ... so ...



(1) “here’s how it looks in ladder logic” ...

(2) “here’s how it looks in function block” ...

(3) “here’s how it looks in structured text” ...

(4) “here’s how it looks in sequential function chart” ...



using the same project over and over makes it easier to concentrate on the programming method - without getting needlessly bogged down in how the machinery functions ... pointing out how each programming method is “similar” to the others - and “different” from the others - has always been the best plan of attack for me ...



action plan: pick a project that will translate (at least moderately well) into all four programming methods ...



if the objective of the class is to demonstrate the similarities and the differences between the different programming methods, then I personally wouldn’t worry too much about which is the “best” way to tackle any particular project ... once the students have a grasp of what makes each programming method “tick” then they shouldn’t have much trouble determining which method would work best with their future projects ...

I want program simatickey .you help call i

The applications I worked earlier are too complex to be taught in a one day session. Can you guys suggest me real world application ( no traffic lights and star-delta starters please ..) and give a small write up about the same?

Interesting that you find your desired example too complicated to teach in one day but you reject something nearly everyone in the world has experience with - namely a traffic light. I agree it is simplistic but you would not have to explain the operation to anyone they already know it. Another good example would be a home washing machine - may be a little harder to mockup than a traffic light.

Dan Bentler

I just finished up teaching a semester and heres some of the various examples I had them program.(some where from the existing currculum, some I came up with).

Traffic lights - I had the students program them using JUST NO/NC/Coils/Timers & Counters, then let them redo it using a sequencer.

Bottle/Box filling machine - This is the LogicPro simulator one and you can make it as simple or complex as you want. I started the students off with the easy stuff like the sampler and the cracked bottle detector then worked up to the filler/capper and cracked bottle disposal section etc.

4-floor Elevator

Simple pump controls/motor start stop. I used this to demonstrate seal-in contacts etc.

Pump lead/lag system - I built on the above example.

Security Keypad with & without 'learning mode' - This one made them think for a while but it taught them how to break up a program so it remains understandable.

Boiler controls - PID controls introduction.

for the inexperienced I found a simple pick & place robot a good one, i.e. part on nest drop pick, grip part retract pick, move to place position drop pick, release part, go back to start.
Although you would not require timers you could introduce them in the sequence to delay the movements this helps to show timer functions & see the logic steps in a slower time (good for explaining the logic).
You could then increase the number of stations, create a standard function for each one & introduce tracking shift registers etc.
This becomes modular for a range of skills level.