To control plant with WinNT.

  • Thread starter Yamashita Taiichiro
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Yamashita Taiichiro

Hello guys.This is Yamashita, working as electric engineer at a Japanese company, and I'm a Japanese.

First of all, I'm not good at English well, so if you cannot understand my e-mail, don't hesitate to ask me the meanings.

Now, I have a question.

We produce optical fiber in our factorys, and the processes are becoming more complicated, so it is difficult to control such processes by PLC now.

So, we decided to use PC/AT based control-systems.

But, we've never used such systems, so there is no informations of that.

Now, I want to ask:

I've heard that WinNT didn't secure about real time responses like RTOS, such as OS-9, VxWorks and QNX. It's depending on the way to use, I mean, when we use some heavy GUIs, programed by VB, the responses would be dull, but don't , really quick.

Even when the other processes are heavy, the main processes for controling can work in milli-second-units, I mean, quicker than 100 milli-second, that would be no problem.

But, I've heard that when used quite heavy processes, sometimes, the response time would up to 1 second or more, and much worse, hung up.

I don't know if we set the priority level properly, the main control process would work.

So, are there someones who use WinNT to control some productive equipment ?

And, how are your systems composed ? Only WinNT? or WinNT + some board PLCs?

And, are there any real time extension products for WinNT ?

Yamashita Taiichiro

Richard Dewees

We are using PC based control from a company called Think and Do but I can't speak for the performance since we haven't gone into production yet. There technical support people have been excellent though.
I believe they use real time extensions to NT produced by Wind River Systems.

Rick Dewees
Ocean Kayak

Phillip O'Meley

There are many Soft PLC systems available for you, many of them use real time extensions for NT. My experience has been with about 12 installations of a product called Waltz. It has and continues to perform remarkably well. When using the real time extension the processor time stayed constant. When we used the system in native NT, we would see the scan time vary when our rather heavy handed and hungry messaging software kicked in. Up to a factor of 10. so from 10 ms to 100ms. The systems comprised of an industrially hardened platform, running NT on
Laptop hard drives with the Soft PLC performing the logic and proprietary software handling the messaging services. As far as a real time extension for NT, I know Venturcom ( has done a lot of good work in this area, and they had some very good papers available. Try them first I just did a search for "Real Time Extension" on the web and ended up with 126 hits. The IEEE site looks good but you will need to become a member to access their information.
Trust this helps
Phill O'Meley
[email protected]
PC based control has come a long way in the last three years.

There are alot of good products that have bypassed the real time issue by running a real time kernel. This is loaded ahead of windows NT giving your control package highest priority of operation so when your controls demand is heavy the Computer Side is slowed (displays, mouse movement, printing). This is hardly noticable with the speed and performance of todays computers. I have tested bothways with and without real time kernels on Pentium III class
systems with only KHz range speed variances.

If you are good at Ladder logic Look into Frameworks PC based control by Total Control/Fanuc. Very easy to get up and runningvat powerful.

If you are into flow type programing look into Steeplechase software. Mitsubishi also prvides their version of Steeplechase called MC2. Very good products all the way around.

hope it helps

Yamashita Taiichiro none

Hi, this is Yamashita.

First of all, I must say thanks for all who sent me e-mails directly and reply to this ML.

And, second, I must apologize to be late for report how to compose our system.

From many, I received advices to use PC/AT(running WinNT or RTOS) and SoftwarePLCs.
But, there is no experience for them, and WinNT (or RTOS) programming. Of cource, no GUIs, it would be simple. But, when about GUIs even on the WinNT, it's too challenging for me. I can use C language on Unix (FreeBSD, Linux, etc.) with GCC, but I've never used GTK+ and GLIB, I mean, I've never built GUIs.

Anyway, even to program on the WinNT is challenging for me, moreover, to learn the usage of software PLC would be too difficult now.

So, we decided to use hardware PLC supplied from OMRON and PC/AT, which are connected via ISA bus, this time. And, for SCADA tool, AIMAX-FA from OMRON (really cheap !!).

In this case, my challengings would be to build GUIs and some VB programs and service programs on WinNT with VC++.

A little bit better than to use SofwarePLCs.

Yamashita Taiichiro none wrote:

> In this case, my challengings would be to build GUIs and some VB programs and service programs on WinNT with VC++. <

I would recommend Borland C++ Builder for NT, it combines VB like ease of GUI development, but your app routines are in the efficient C you need for control/comms.

Likewise for Linux I would recommend the Kdevelop package, not because K is necessarily better than GTK, but the GTK development tools are not as
complete, and you will have to code some of the interface by hand, wheras K develop has a graphical dialog/form editor.
I am experienced GUI using wonderware and running on WinNT.

i think to solved your problem, not because WInNT but what IO server your using because if you would builds GUIs you no problem usng VB, but you must using IO server good perfomance

You can use any PLCs if you have IO server compatible.

Yamashita Taiichiro

In this case, this "IO server" means a kind of bridge between PLCs and PC/AT machine ?

If so, I could purchase that "IO server" product from OMRON, named "FinsGateway".