Re: New forum topic - Open Control
Feb 17, 2002 1:54 pm, by Michael Griffin
Text :
<clip>
> If I were the plant operator, the one who purchases the software and pays
> your wages, I would be more comfortable with AB over Linux. With AB I am
> assured of a basic standard of software operation that I know will be the
> same from the time I purchase it 'till I am convinced to purchase an
> upgrade.

This is based on the assumption that "EPROMS don't change". There are two
problems with this argument. The first problem is that if EPROMs can't be changed, then they won't change if you have open source or proprietary software.
The second problem is that a lot of newer proprietary systems are built with flash EPROM. If you use a newer version of programming software (or an integrator or one of his subcontractors does), the programming software may download a new firmware revision into the hardware. It may even do this without telling you what it is doing (you just notice that the program download is taking longer than normal).
Some newer proprietary hardware is being shipped with nothing loaded into the firmware except a simple loader. The version of firmware which ends up in it depends upon what was on the hard drive of the computer used to program it. You could buy two identical pieces of hardware, but end up with different firmware in them when you download your applications.
This of course doesn't deal with the question of new equipment or repairs. If you order a new PLC this year, it isn't going to come with the same firmware as the one you bought a year ago. The manufacturer will likely have fixed bugs and added new features.

Even having conventional EPROMs doesn't guarranty that they are stock parts. We have stuff (not PLCs though) with custom EPROMs. All we had to do was to supply the manufacturer with a spec for the modifications we needed. There is nothing to stop one of your employees from doing the same thing.

Given the above, I am not sure why you feel that buying AB hardware will result in the "fundamental features" of the hardware being identical. You might argue that AB sells very good hardware, but that is another issue (and
another topic) altogether.

> This insures that in my plant's near future I will be protected by
> a warranty, I will know that one part of my empire has basically the same
> infrastructure as the other parts, I can send solutions from one plant area
> to another without worrying if some eager beaver has changed the
> infrastructure so that it is no longer compatible.

Your warranty with any control hardware manufacturer will be limited at most to the return of any non-functional hardware or software. They aren't going to "protect" you from any other consequences of changes they make to their product line. It would be unreasonable to expect them to do so.

> I can hire new employees
> that will know the AB infrastructure, I can transfer employees, with the
> assurance that they will not need to spend their time and my money
> determining how the infrastructure is engineered. All this to keep costs
> and problems down and production constant.

This is training, not open source versus closed. You can hire new employees who have worked with AB's hardware before because there is so much of it already in use elsewhere. However, if AB were to introduce a new product
which was unrelated to any of their existing product lines, your argument would not be valid.


> Another point - If I were a plant operator I would not buy software. I
> would purchase tools, software tools that you were able to use without
> adding further expense. I would try to purchase tools that you would not
> need to take apart and then put back together in order to make it work. I
> would do my best to buy those tools that don't require further time, effort
> and my money to make them work.

Have you had any luck with this? I'm sure a lot of people would like to know where to buy software that works the way it is supposed to. I've spent far too much time and money on the usual kind, and there doesn't seem to be much correlation between the price of the software and the quality of the product.

> Linux is a dream come true for the creative techs who want to solve
> problems effectively, quickly and by putting a little of themselves into
> the work.
>
> But - until I, as a plant operator (example only), can be satisfied that my
> concerns outlined above are satisfied, then I will be extremely reluctant
> to purchase open source.
<clip>

I think your last sentence is pretty close to your real reasons. The real issue for you is that you are pretty happy with what you have been getting from AB, and don't feel any compelling reason to change. No doubt you have bigger problems to worry about than any that AB has been giving you.

However, let me ask you a question. If AB introduced a new product that used a Linux operating system, would you consider buying it? If all their new operator interface terminals used "Rockwell Linux" to host the application, would you then switch to a different brand of hardware to avoid it?


--

************************
Michael Griffin
London, Ont. Canada
************************
Reply