Re: RTOSes, PLCs and control

C

Thread Starter

Curt Wuollet

Hi Pete

Why would anybody who cares enough to write Open Source code on Linux want to depend on MS proprietary protocols and having a Windows box
in the mix? At that point your system is neither Open or Free as in Freedom. I would think people who care enough to give us a chance would like an Open System from one end to the other. It's binary
rather than a continuum. Being a little proprietary is like being a little pregnant. This by the way, is IMHO, others take a more pragmatic view. There may be compromises we have to make, but OPC isn't worth compromising for. I just don't see the reasons for mixed environments. Folks who think Windows is necessary or even
adequate are unlikely candidates. Just my personal view. For the project, we'll do what we have to do. We should offer an Open
alternative.

Regards

cww

Peter Wurmsdobler wrote:
>
> Chaire Chiron !
>
> On the one hand PuffinSCADA could talk to matPLC over a server sitting
> on top of matPLC and being implemented with code from both PuffinSCADA
> and matPLC. On the other, could a server be implemented on a non-UNIX
> machine with PuffinSCADA libraries, which talks both to the OpenPCS PLC
> programming environment and matPLC?
>
> Now I use a word like in Monty Python's film "The Holy Gral": We are the
> knights who say: Ni! Ni! OPC! Using again PuffinSCADA library elements,
> would it be possible to implement something which talks PuffinSCADA on
> one side, and OPC on the other? I know, OPC is based on MS technology,
> yours on UNIX standards.
>
> If I understand correctly from our Houston conversation, PuffinSCADA
> offers a sophisticated protocoll between modules, clients and server,
> tailored for automation. I do not know both this protocoll and OPC
> in detail, but does the PuffinSCADA protocoll a similar functionality.
> Finally, how can a PuffinSCADA system talk to other automation software
> other than in Puffin ?
>
> Still searching for a multi-element solution THE PuffinControl,
> peter
> --
> Peter Wurmsdobler
> Control.com Inc.
> 508-621-3611 fon
> 508-621-3614 fax

--
Free Tools!
Machine Automation Tools (LinuxPLC) Free, Truly Open & Publicly Owned
Industrial Automation Software For Linux. mat.sourceforge.net.
Day Job: Heartland Engineering, Automation & ATE for Automotive
Rebuilders.
Consultancy: Wide Open Technologies: Moving Business & Automation to
Linux.

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G
Curt,

It seems to me that the two most successfull applications on Linux are Apache and Samba. These two apps have more to do with people switching away from Microsoft product than all other Linux applications combined. Both applications, especially the second, are designed to interact with Windows machines. It seems like these apps are winning the battle by chipping away the stone in a continuous manner, rather than blowing it up in a binary manner.

--
Gary James
http://home.twcny.rr.com/embedded/
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C

Chiron Consulting

Curt wrote:

> Hi Pete
>
> Why would anybody who cares enough to write Open Source code on Linux
> want to depend on MS proprietary protocols and having a Windows box
> in the mix?

I don't think that's the right question. I don't "want to depend on MS proprietary protocols". The question is "why would anybody be willing to support an MS - or any other - proprietary protocol?" And the answer is,
"because somebody's willing to pay for it". For example...

I have a client who loves his WonderWare screens. His plant automation philosophy is "control on Linux, pretty pictures on Windows". He's got no particular interest in OPC, no interest in pulling process data into
Access with ODBC, etc... he just wants easy-to-build, easy-to-use screens for his operators, and he's settled on WonderWare as his tool of choice.
Until I can offer him a Linux package that he feels does operator screens as well as WonderWare, that's what he's going to use. And I'm not going to pass on his projects just because he wants a WonderWare SuiteLink driver for PuffinSCADA.

If somebody came along tomorrow and said they wanted to use PuffinSCADA on a project but required an OPC server, I'd quote a price for the
development.

I'm an Open Source advocate and user and contributor, but I don't require that my clients be committed to Linux purity, and my willingness to develop a given feature is driven in part by what my clients demand.

> At that point your system is neither Open or Free as in
> Freedom.

No, but it's a system somebody's willing to pay me to deploy, and that's the only reason the system exists in the first place.

> This by the way, is IMHO, others take a more pragmatic view.
> There may be compromises we have to make, but OPC
> isn't worth compromising for.

I guess I qualify as a pragmatist. If it isn't illegal or immoral, then there's a dollar value that will make it worth my time to do.

> We should offer an Open alternative.

Absolutely. No question about it. We're working on it.

Regards,
Greg Goodman
Chiron Consulting


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C

Curt Wuollet

Hi Gary

That's true but that's a different arena and typically people who know both systems. In my experience, which is considerable in the
business of conversions, there is almost no such thing as a successful partial Windows environment that doesn't tend towards a total Windows environment. Nearly all MS's effort is devoted
to making such a thing impractical with both their marketing and their manipulation of protocols and file formats. Everything bad that happens is "because you're not using MS". Even the Windows crashes get blamed on the "foreign" software. And if there are Windows devotees in the crowd, you have a major political
headache.
And if the strategy didn't work, they wouldn't have a monopoly You start out such things on shaky ground and except for file and print servers and possibly web servers that can be made
invisible and transparent, you have to win the war over and over every day. The worst is office software where anything that is not an exact copy of Word or whatever is junk, no matter how well
it works. I have tried both, and total replacement has a much better chance of success and happy customers. There is no rational
explanation for it. I would (and do) advise people to change or not change as those states in between are more or less continuous conflict. You are fighting the strongest advantages of a monopoly, "change and hassle avoidance" and it never goes away as long as there is the option of not changing.

This is IMHO why Linux gains market share on servers and not on the desktop. Servers are a complete change and there's no opportunity for hedging. Some of my most radical opinions are
based on harsh reality rather that the idealism that is often supposed. The technical problems are trivial compared to the people problems.

Just my experience selling Linux to non-techies. I'm not at all criticizing you, just explaining where I'm coming from. We will probably have to live with mixed systems, it just makes things
a lot harder.

Regards

cww

--
Free Tools!
Machine Automation Tools (LinuxPLC) Free, Truly Open & Publicly Owned
Industrial Automation Software For Linux. mat.sourceforge.net.
Day Job: Heartland Engineering, Automation & ATE for Automotive
Rebuilders.
Consultancy: Wide Open Technologies: Moving Business & Automation to
Linux.

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Curt Wuollet

Hi Greg

I can understand your point of view, especially as I'm trying to get cash together to buy some propane. It's no longer possible to ignore
that Winter is around the corner when it's 55 degrees in here. The other side of that issue is that, as I was telling Peter, with the monopoly and the mindset of the majors in the industry, it takes only a little compromise here and there to preserve the status quo forever. And it is my stated purpose to bring about change. That's
why my focus is on a system free and Open end to end. I am in a perhaps unique position in that I do my work entirely with Linux and the only contact I have with Windows is to replace it. I do work with proprietary products to the extent it takes to integrate them with Linux, existing Robots and CNC are not replaceable just yet.
I can afford to do things this way so far although the dark side would be far more comfortable. Any compromise would have made the
picture very, very, different, no advancement would be visible and most certainly no one in my little world would ever know that it is
possible and indeed very favorable to build automation with Linux.
My point is that, it's that last 10% of committment that has brought about change where none existed before. It _is_ very difficult to
change things, but without the committment it simply won't happen. I guess that would make me a zealot, but my day job company runs Linux and is happy and our Linux automation is running 24x7 and
performing so well it gets noticed, and I don't have to make any excuses to my consulting customers. And people all over the world are reading this. It's just my way of accomplishing things. Sorta pragmatic in it's own way. It's what it takes to change things. I don't expect everyone to do it the same way as long as they plan to change things rather than accept them. If we accept things as they are, that doesn't include OSS and Linux.

Regards

cww

--
Free Tools!
Machine Automation Tools (LinuxPLC) Free, Truly Open & Publicly Owned
Industrial Automation Software For Linux. mat.sourceforge.net.
Day Job: Heartland Engineering, Automation & ATE for Automotive
Rebuilders.
Consultancy: Wide Open Technologies: Moving Business & Automation to
Linux.

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Peter Wurmsdobler

Curt & Gary,

just to put oil into the fire. As a ThinkingNerds.com, I can tell you: we hosted our site on a Linux box at a MS certified provider, the only Linux machine, uptime 400 days until they pushed the machine back to the wall which stopped ventilation. It was a pain in the ass of the manager that this small little 486 had a long uptime and their NT stations needed a reboot from time to time, no reason why. But then they needed a FAX server. So Nicholas installed one on Linux,
they annouced it on their site. Few days later the provider got a phone call from MS-Austria that they better should remove all Linux boxes, if not they loose their certification.

The same happened to a school, where Nicholas installed a linux print server: They lost the school rebate because there were another machine on the net than MS. But the school had it easier: Just remove all MS PCs, and pay nothing at all !

If you deal with MS, you sign for entire dependance. And open cooperation with other products and standards is neither appreciated nor encouraged.

When starting the real time linux workshops, my declared goal was: Help pushing alternatives to MS products and don't let them become monopolists in the rt&embedded market. "Ceterum censeo Mircosoftem delendam esse" is now extended to simply: "In tyrannos".

peter
--
Peter Wurmsdobler
Control.com Inc.
508-621-3611 fon
508-621-3614 fax

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Curt Wuollet

And It'll get worse before it gets any better. MS is frantically getting as much dirty work done as possible knowing that remedies will probably limit future behaviour. This is the stuff that the DOJ case should have been about. A much clearer abuse of monopoly power and much more
damaging than bundling Internet Exploder with the OS. These exclusivity deals are preventing a lot of folks from pre-installing Linux at the risk of losing the Windows pricing they need to be competitive. Even Dell caved when their margins were threatened. This is not even considering their latest push for legislation that would make Linux illegal.

Regards

cww

--
Free Tools!
Machine Automation Tools (LinuxPLC) Free, Truly Open & Publicly Owned
Industrial Automation Software For Linux. mat.sourceforge.net.
Day Job: Heartland Engineering, Automation & ATE for Automotive Rebuilders.
Consultancy: Wide Open Technologies: Moving Business & Automation to Linux.

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Gary/Curt et al.

Some of us don't even require "chipping away." We just want to be able to coexist, an effort which Microsoft does its best to either
eliminate as an option, or at least get paid a license fee for the privilege.

I think I coined the term for Microsoft's modus vivendi as: "A hand in every pocket." I'm old enough to remember the old days of Microsoft's compilers, where they wanted to be paid a royalty for every application compiled... Fortunately, that policy was short-lived.

Curt is fortunate and/or skilled enough to be able to live in a non-Windows environment. The rest of us our not so lucky.

I think it would be foolish to be explicitly incompatible with MS. But I think we should also avoid Microsoft proprietary also. The closest we should get is providing a gateway, or protocol converter, to convert from our universal, open protocol, to/from Microsoft's. I think there will be many cases where we need at least *some* Microsoft. Not all system components will qualify for replacement, no matter how slick a system we create.

Rufus

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P
One day, a chemical plant operator is going to be unable to respond to an emergency, because his OPC server crashed or his mouseball was glued up, and we are going to see a really big boiler explosion (Algiers, January 2004?) or an ammonium nitrate explosion or a gas plant explosion. And then we will see a very big lawsuit against your favourite company. We should not underestimate the seriousness of this issue.

Paul Wilson
Process Control Engineer
 
Safety systems should be outboard of any processor based device, including any mainstream PLC or DCS. There are specialized systems that are firmware based, e.g. FSC that are available for these types of applications. Others may use logic board systems or hardwired, redundant and "fail-safe" shutoff devices.

We operate Linux and Windows2000 servers along side of PLC and DCS. For the users they see no difference in reliability.

We've found the OS's fine and the commodity IT hardware to be great as well. A lot of the Windows-based software is pretty sluggish and unreliable. That is why we have written our applications in the POSIX standard (Unix/Linux). Put a quality server alone in a room with no applications and let it run. It will be fine for more than a few years.

Paul Jager
www.automationX.ca
 
M

Michael Griffin

Re: Paul Wilson & Software

If by "your favourite company" you are referring to Microsoft, then may I offer the following excerpts from their Windows XP license.

"Microsoft and its suppliers provide the Product and support services (if any) AS IS AND WITH ALL FAULTS, and hereby disclaim all other warranties and conditions, ...(including) accuracy or completeness of responses, of results, of workmanlike effort, of lack of viruses, and of lack of negligence, ..."

"IN NO EVENT SHALL MICROSOFT OR ITS SUPPLIERS BE LIABLE ... FOR BUSINESS INTERRUPTION, FOR PERSONAL INJURY, ... FOR FAILURE TO MEET ANY DUTY INCLUDING OF GOOD FAITH OR OF REASONABLE CARE, FOR NEGLIGENCE, ... EVEN IN THE EVENT OF
THE FAULT, TORT (INCLUDING NEGLIGENCE), STRICT LIABILITY, BREACH OF CONTRACT OR BREACH OF WARRANTY OF MICROSOFT OR ANY SUPPLIER, AND EVEN IF MICROSOFT OR ANY SUPPLIER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES."

Have a good look at the above. Microsoft isn't claiming that their software is reliable. Companies in the finance and retailing businesses have already lost stacks of money because of Windows security problems. None of them has
successfully sued Microsoft over problems with Windows, so I don't think an industrial customer is going to do any better.
--

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