Allen-Bradley or Direct PLC DL-05?

[mmw]

Steve -
I think you hit the nail on the head (if I can use a mechanical analogy) by using the word "learn". Some can't; many more just simply don't want to.

 

[Tom Jenkins]

Well, mmw ole pardner, I ain't niver been much of a carpenter - jist buildin' hog pens and sich. But I figger ya might o' lost sight o' the original question, which was how to teach high school students. It may be obvious to you which deerecshun is upload and which is download, but I doubt it is intuitively obvious ta them. I reckined we wanted to get them kids excited about possibilities o' automashun engineerin' and I didn't figger the instructor had a whole semester available fer instructin' them.

I ain't niver used a PLC-2, and I has no doubt thet at my first encounter I will be forced to run screamin' fer my life an' lookin' fer help!

 

[rsdoran]

I dont think that was a fair representation of AB with RSLogix. As with most brands you do a hardware configuration and the I/O data files will be preset dependent on type of I/O. By default you have internal bit(s)(B3) pre-configured, as are all the other Data Files.
If another word file is needed in the program all you have to do is use the next unused bit number, it will create another file automatically.

I dont care much for RSLinx but with so many different choices on communication I guess they needed that in a separate package to work with multiple models of their plc's.

Now for the other side of that, I have 6 machines that are using SLC 500 L-30D which when they fail I will replace with an A&D model.

I like cream and sugar in my coffee, not every one does.

 

[Allen Nelson]

Tom:

Your wrong about needing to needing to create the data tables first. If you enter an address that hasn't been used yet, RSLogix (heck, even old DOS AI) will expand the data table automatically.

You can get in trouble if you decide you want to have a data file 10, and in one instance think that it should be configured as an integer (N10) and another as a timer (T10), but that's also part of the strength of AB, the ability to help you organize your data tables (ex: All Alarm timers are in T24:, all setpoints are in F48, etc)

I never have had a problem with AB's method of I/O addressing (I:3/0 = the input in the 0th point on the fourth card (counting from zero). I haven't used AD, so I can't comment. If you add a card in the middle of a rack in the middle of a project, do you need to change all your addressing, or is there some sort of Modico-like "Traffic Cop" to map the modules to internal registers. Probably not, since you say you don't have to do anything, and it's irrelevant to the point of the thread, which was so predictible in it's invitation for AB-bashing/-advocating that I posted a warning to ignore it all before it happened.

As to upload/download, I never can remember which is "up" or "down", no matter what system I'm working with. I always look at the helper words 'to' and 'from'. I don't get confused which way things are going as if it says "Download to PLC" or "Download from PLC". AB's interface does make it clear which it's doing, even if it may seem backwards to some.

 

[mmw]

A good instructor can drive any vehicle. Tell me, Mr. Jenkins, just how much teaching experience do you have?

Dan - Allen was probably right; ignore all of this and go with your budget. You're probably painted into that corner anyway. Good luck.

 

[93lt1]

banghead

Over and over and over and over...........

 

[Tom Jenkins]

Allen and Ron, you are of course correct and there are alternate ways to do lots of jobs in RSLogix. That power brings attendant complexities. The point I was trying to make, in response to the specific questions from mmw and Mr Stacy (remember him?), was exactly what aspects of A-B PLC programming I thought were more complicated. If mmw or others don't feel that configuring files or using the specific format that A-B has used to maintain backward compatibility with older models is more complicated, that's OK. I tried to make it very clear that I wasn't A-B bashing, just trying to explain why I (me, as in my personal opinion) thought ADC was easier to use for teaching ladder logic to high school students. In fact, I went out of my way to say I liked many things about A-B, and that a point in their favor was the huge installed base!

As far as my experience as an instructor, although I'm not sure why it matters, I have taught several courses in automation at Waukesha County Technical Institute, including recent high school grads and "returning students" from industry. I have also taught basic PC classes at Milwaukee Area Technical College, and most of my students in those classes were post retirement. Believe me, I learned there is nothing obvious about "download" and "upload", or any other jargon for that matter! I've also trained many students and interns working for my company, some of whom have worked for me after graduation and many others who have come back years later and thanked me for the training and professional development they obtained from me!

And now, if for no other reason than sympathy for 93It1, please let this thread die!

 

[mmw]

Wow, I had no idea about your illustrious background in the hallowed halls of academia.
Although trembling with awe, I will humbly and respectfully leave this thread.

 

[Rick Densing]

If AB is so complicated, wouldn't you want to teach that? Then your students would find everything else easy.

Seriously, the main goal that your students had in mind when enrolling at your school is to develop skills that will give them a greater chance of being employed. That said, depending on your location, AB has the market share (as mentioned before) and you will be imparting on your students greater marketability.

Another note- Intuitive is a very subjective term. One person's intuition is another's confustion.

 

[akreel]

If AB is so complicated, wouldn't you want to teach that? Then your students would find everything else easy.

I've been away from this thread too long! Tom's taking all the hits!

Wouldn't you want to teach AB first? For some reason, many of the people I've known who started with AB can't (or won't?) adapt to something else. Maybe it's because they get too used to the bells and whistles (is that spinning ladder a hypnosis tool?) that Tom is talking about. ("Where the heck is my magic 'DO ALL' button?") I can see why Allen Bradley does many of the things they do; some things happen because they added stuff later (after thoughts are always fun), other things are supposed to give you more control. Like they say: one it works, it runs like a champ. But working with AB usually takes me longer than I think it should. It's all those "features." A typcial programming session reminds me so much of working with Windows:

Me: OK, download.
RSLogix: Really? I don't think the PLC is ready.
Me: Make it ready.
RSLogix: There's already something in there and the PLC is busy, you know.
Me: I can see that. Go ahead.
RSLogix: All right, but don't say I didn't warn you. You can't Undo this you know.

Granted, most software does this. It should, actually. It's the fact that there are SO many of these "interruptions," and sometimes my responses really don't matter. For me, it's the "attitude" of RSLogix that makes me want to do brain surgery with a sledge hammer. This is the kind of thing that REALLY annoys me:

Me: Run.
RSLogix: You know, you forgot to set up these vestigial parameters on that one module over there.
Me: It's OK. I'm not using it yet.
RSLogix: But you might use it.
Me: TRUST ME. I'm not!
RSLogix: Well, let me show you what I'm talking about anyway.
Me: ARGHHHH!
RSLogix: Did you leave the oven on? I smell something burning.

The root of the problem for guys like Tom and myself is that all the "ADVANCED" features of the software are so prevalent in routine programming. The default mode ought to be less "invasive." I guess what I'm trying to say is: the more "powerful" features of the program shouldn't be getting top billing when I select a menu.

True story, this is probably going to get me FLAMED! The first time I tried to print ladder from RSLogix500, everything was highlighted or really light. It looked nothing like what was on my screen, because I'd turned off highlighting. Well, as you RSLogix people (an now I) know, you have to configure the print settings SEPARATELY. What especially annoyed me about this is that the print settings DIDN'T get prominent linkage, so when I wanted to retune them I had to try and remember where I found that option... "File" menu, "Report Options," Ok, try the "Program files" tab... OH! The "Ladder View" button!

What other program has you go through that to set up your printout (RSLogix5 and RsLogix5000 DON'T COUNT!)? Has anyone ever heard of WYSIWYG?

AK

 

[Rick Densing]

I guess I should have put a after my comment. I was not taking a swipe at anyone.

 

[akreel]

I guess I should have put a after my comment. I was not taking a swipe at anyone.

It wasn't you, Rick. It was mmw with his grand total of 17 posts that was getting me. I'm surprised Tom spent any of his time responding. I'd bet anything mmw is actually that 100011110011100 guy posting again to get us all riled up.

Oh, and by the way (before anyone tries to call me on it). I AM aware of the checkbox on the print setup for RSLogix that says "Use program view...." Mine was set to OFF by default. I assume everyone who uses that particular build of RSLogix encounters the same thing, unless my computer is just out to get me.

AK

 

[mmw]

funny, Mr. 128

and ak, I'm not the 1010100010 guy if that's who you're referring to. He/she appears to be the epitome of post #16 in this thread.

 

[TimothyMoulder]

Remember the audience

Ya know, this presentation is supposed to be going out to high school kids. Those who aren't snoring will be day-dreaming about the girl or guy two rows over.

On the odd chance that somebody might be paying attention, there is no reason to overwhelm them with a powerhouse piece of software like RSLogix. Get something dirt-simple and easy to use. A Unitronics M90 is right up this line, and relatively cheap.

My two bits

TM

 

[rsdoran]

Yes there are other brands

I should have mentioned this before, FUJI ELECTRIC
<<a link
also has plc's as low as $81 and the software is free. For a high school they also may lower that or provide a demo. If by any chance any student(s) are serious this may be within their price range for an experiment.