> ------------ Forwarded Message ------------
> From: tecnog
> To: [email protected]
> Subject: Re: PLCS: Need to Setup a PLC Lab
>
> If the lab is to be setup "for academical purposes", as
> stated by Mariano, I would suggest the evaluation of softPLCs, better if
under
> GNU license and Linux operating system. There's nothing cheaper.

I do not know of any such beast that works and is in any sort of production
format. If the topic of the class is "writing softplcs", then sure, go get
MAT actually working with a ladder editor. Otherwise, go and actually buy a
PLC. I think what students want to learn -- how to program ladder logic --
can be taught very effectively using small AB Micrologix or Automation
Direct 05s or what have you.

> 1. in automation world , micro-PLCs are mostly used only
> by a small part of integrators and mainly for a specific family of
> applications (e.g. packaging). Many of them do not allow online
programming and
> have reduced fieldbus/networking/communication capabilities. Mastering one

> of these PLCs will not ensure one will be able to program other PLCs in a
> reasonably short time.

Mastering any one family of PLC and its specific software, even the
compilcated ones, doesn't mean that it will be easier to learn another PLC.

> 2. PLC software simulators often do not provide a complete
instruction
> set and proper CPU behaviour. The editors are not the same you will use in

> the real world, so they're still useful for "academical purposes" but not
> for real training. The only simulators worth some money are those
> developed by main PLC brands themselves (e.g. Siemens, etc),
> where you use exactly the same tools (editor, Xreference,hardware
> configurator) and the identical instruction set you would use in the real
world.

So don't buy simulators. Buy small PLCs from the company that gives you the
best deal.

Alex Pavloff -- [email protected]
Eason Technology --- www.eason.com
--- Linux-based industrial HMI ---
-------- www.eason.com/5k --------

 

I have to agree with Alex here except for a couple small points. The first is, of course, the slamming of our project. In a typical educational environment where the emphasis is not on experience setting up and using an "industry representative" product, but learning that this logic does that, MAT could provide a lot of
seats at very low cost. Indeed the computer labs needed for other classes could be pressed into service with something like the parallel port interface to provide large numbers of students an
education experience in how logic works at almost zero cost. If you are training direct labor, then the micros and specific equipment might be better. But, if you were giving CS students a unit on IA the ability to see how MAT works could also be of great value. Indeed Mario has had some of his students actually code parts, I believe. Try to have them do that for the experience with a SLC500. In fact, have them try to find out exactly how it, or any of it's myraid functionally identical parallel competitors
do things without paying for training. _That_ would be a very valuable experience for engineers looking to be automation decision makers. Education is about information, keeping that information secret and selling it just doesn't jive well with education. When the basic info you really need to teach a class is a "RSLogix 500 Procedures Guide" at $103.00, and not publishable on the net, or legally reproducable, it excludes even me from an education, along with direct labor or CS students.

Last, we get many requests here from individuals seeking to get into automation or transition from other fields. How many working people can afford $5000.00 to learn to program a SLC500 typical of what's used in industry? That's my estimate by the time you buy a machine, a useful assortment of cards and the manuals, cables, etc. That's not hype, it's fact. And I do give credit where credit is due for their encouraging effort with the ML1000 with free software. And that would work for most other folks who own or run Windows.
But for most working individuals, even that is pretty spendy and I'm not sure you still wouldn't need to buy some books to make use of it. None of this is a problem for industry, they're used to traumatic sticker shock. But for educators and individuals? Give me a free PLC with free docs anytime. It's the difference between doable and
not. I can cope with the minor transition to RSLogix when someone rich buys a copy for my use.

Regards

cww

 

At 04:09 PM 07/05/2003 -0400, you wrote:
> > the real world, so they're still useful for "academical purposes" but not
> > for real training. The only simulators worth some money are those
> > developed by main PLC brands themselves (e.g. Siemens, etc),
> > where you use exactly the same tools (editor, Xreference,hardware
> > configurator) and the identical instruction set you would use in the real
>world.
>
>So don't buy simulators. Buy small PLCs from the company that gives you the
>best deal.

The use of a good simulator is still useful if compared to a complete PLC +
I/O + HW application system. Again, it must be a *good" simulator, which
integrates smoothly into the official PLC developing environment, otherwise
it would be of little help unless you use it for very basic learning.
Once you have such a simulator, it is really a cost-effective tool for
educational purposes and lab tests.
I'm developing something, based upon Siemens PLCSIM. If interested you can
take a look at
http://www.runmode.com/r_s7trainer/f_s7trainer.htm

best regards
Luca Gallina

 

I would agree with Mr Technog, but a great deal depends on what level of intruction is contemplated. For an introductory course, your needs are much different than an industry sponsered, "hire the graduates directly to work on such and such course". For the former and
intermediate, simulators and micros, especially if they share the same procedures and intruction set as the more prevelent products,should be
fine. For specialties, you may need equipment very similar to the target to be relevent. And trust me, from recent experience, building a machine is often less damanding than having to fix a variety of unfamiliar machines. And the skill set is much different. You need to know little more than how to run the tools, but deducing the theory of operation and sequence are important along with just about everything but the PLC.

Regards

cww