Linux Anyone?

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Thread Starter

Christopher

If there were a Linux Automation programming package and or data acquisition package would there be any interest in it?

Just curious, I'd appreciate any feedback.

One thing I ought to mention. With Linux once it is set up it is hard to screw it up w/o root access. So if you set up a laptop for maintenance say, you wouldn't have to worry about people changing settings and screwing it up!

Chris
 
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Michael Griffin

What do you mean by a "Linux Automation programming package" or "data aquisition package"? Those phrases can cover a lot of different areas.

If you are looking for ideas for a product or service involving Linux, I do have a suggestion. You could put together a development system targeted towards automatic test equipment. This would be a package of various software which someone who is building test equipment could use to write test programs. Much of this software already exists, but would need to be selected, tested, and packaged together. This could involve:

1) Real time Linux (real time response simplifies test sequencing and control).
2) Development software to write the test program. This could be a 'C' or Java compiler or something similar.
3) Software to create the various tester screens quickly and easily. These would include screen controls such as strip charts, push buttons, indicators, etc. This would work in conjunction with the previous item.
4) Drivers for various popular GPIB and data aquisition boards.
5) Math and signal processing libraries.
6) Documentation on how how the various bits mentioned above can be made to work together. This should include a few very simple example applications.

The target market for the above would be the small companies who develop custom one-off test systems for industrial customers. They currently tend to use Visual Basic or National Instruments Labview or Labwindows with a Windows NT operating system.

This market may be well suited for Linux, as the equipment generally runs a single custom designed application and nothing else, so compatability with other commercially packaged software is not an issue. The final customer for the test equipment simply wants to turn on the machine and have it test parts. As long as the tester works, he would rather not see Windows
(or Linux) at all so familiarity with the operating system is not an issue for them either.

Many of the people who develop these systems have an expertise in test and instrumentation. They do not have the time or interest to become Windows NT experts as well. They seem to learn just enough about Windows to
get by. If Linux is offered to them as something that supports the application with the required features but otherwise stays out of their way,
it could be a big help to them. The reason they generally pick Visual Basic or Labwindows and Windows NT now is because that is what is readily
available. Windows NT is a bit too general purpose to be a good fit for this application though. The trick is to offer them something as a complete "test equipment software development system" package with suitable documentation and examples so they don't have to search out or create all the bits and pieces for themselves.


**********************
Michael Griffin
London, Ont. Canada
[email protected]
**********************
 
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Wan Chon Kong

Try Vispro from www.vsys.de
I saw the software in Germany Interkama '99 show and I was convinced of the stability and speed of the software compare to any Window based HMI software. Only problem is the PLC driver support.

Wan
 
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Curt Wuollet

Hi Christopher

Of course there would be interest in it. There already is a package called AutomationX and we at the Linux PLC project will eventually get to a
programming package. The National Instruments LabView package is available for Linux for data acquisition. I prefer to code my own, but easy alternatives would always be welcome.

Regards

Curt Wuollet, Owner
Wide Open Technologies
 
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Adi Purnomo Sopamena

Christopher,

Basically there are a lot of Linux Automation Programming packages. You should have only a programming software package which can be compatible to UNIX platform. You can also have a security system or access system to protect your laptop. Hopefully this is the way out.

Adi Purnomo S
Sales & Marketing Manager
e-mail : [email protected]
Phone : 62-21-8649318
Fax : 62-21-8649316
 
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Warren Postma

> One thing I ought to mention. With Linux once it is set up it is hard
> to screw it up w/o root access. So if you set up a laptop for
> maintenance say, you wouldn't have to worry about people changing
> settings and screwing it up!

If you have a typical system, there is zero security once you are physically present at the keyboard of the machine. The easiest way to get root access and screw things up is to type in "LINUX SINGLE". Works on my redhat 6.2 system and totally bypasses all system security measures! :)

Just goes to show you that nothing is automatically secure, you have to audit just about anything to even get a reasonable amount of security.

Warren
 
Hello there,
What is the significant difference between ordinay Linux (Slackware, Redhat and other commercial brand..) and a real time version ?

regards.
 
K
> ------- Forwarded message follows -------
> From: "Wan Chon Kong" <[email protected]>
>
> Try Vispro from www.vsys.de
> I saw the software in Germany Interkama '99 show and I was
> convinced of the stability and speed of the software compare to any
> Window based HMI software. Only problem is the PLC driver
> support.

This looks very interesting, and a demo is even part of the SuSE Linux distribution, so should be easy to check out. I've been unable to find any information on the product in English, however, but I'm hoping that is or will be available.

> > From: "Christopher" <[email protected]>
>
> > If there were a Linux Automation programming package and or data
> > acquisition package would there be any interest in it?

I'm sure there is much interest in this. I'm working on a generic approach, where email and web servers can make backend queries against a plc server.

--
Ken Irving
Trident Software
[email protected]
 
J
Chris,

Check out www.linuxplc.org which is an ongoing effort to produce just what you described. We are currently working on the controls, but I am sure the DA will follow.

There is allegedly a Java based scada package for linux, but the name escapes me at the moment. I beleive it was jaguar or panther or something
similar to that, but not sure. Anyone else know of this package?
 
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Prabhat Ranjan

Real time version of Linux (specifically RTLinux ) comes with a patch for a specific version of Linux kernel distribution. I have used RTLinux
version 1.0 and right now I am using RTLinux version 2.0. RTLinux gives direct access to hardware and if one has a DOS driver source, its not difficult to get it working for RTLinux. This is not the case for a Normal Linux Kernel, where device drivers are little more difficult to write.
RTLinux v 2.0 is more POSIX compliant and we did not have much difficulty in changing the device driver from v1.0 to v2.0.

I hope this helps!

- Prabhat Ranjan
 
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Anthony Kerstens

Just curious. It's "LINUX SINGLE", in all upper case, entered into the login prompt, without a password?

And is there a way of disabling this?

Anthony Kerstens P.Eng.
 
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> I'm sure there is much interest in this. I'm working on a generic
> approach, where email and web servers can make backend queries
> against a plc server.

I have given up on just about anything high level, I hook everything up with basic TCP/IP messages.

Funny thing is it works great, runs on anything with TCP/IP, and it needs very little coding

(ex. I have a unit that bridges a 485 multi-drop connection to TCP/IP that allows any number of users to issue commands on the 485 from anywhere on the network. This took about 20 lines of Python code on a Linux box for the gateway, and about 15 lines of VB code on the client to replace the code that would ordinarily be used for the serial.)

There is a companion to the re-install it mindset, it is the 'I could not possibly do it without $2000 software module' mindset. KISS.
 
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Peter Placek

Hi,

Concerning the communication with PLC's and other devices under Linux, I believe OPC might be the right way.

The problem is DCOM for Linux. But it seems to be solved by porting it as e.g. Software AG has done.

We are doing tests in our company and have first two beta versions of OPC servers ready. We also successfully applied for IST grant (European Committee) thus we have started an extensive OPC
project for Linux recently - the goal is low cost SCADA and OPC tools.

Peter Placek.

Merz Company
tel: +420 48 510 0272, fax: +420 48 510 0273
http://www.merz-sw.com
for Clean Sound of Software
 
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Warren Postma

I usually type it in as lowercase, but I believe its not case sensitive. No password necessary. For information on disabling this little back-door, or at least password protecting it, see the LILO documentation. You much with the contents of /etc/lilo.conf, then run lilo again, and it will protect you against that.

Warren
 
M
I think we have an oversimplification here.

The ability to change the run state is limited to the root user. However at boot time anyone sitting at the keyboard is considered the super-user (ie-root privileges) and can enter boot options.

So, if LILO is configured to accept keyboard commands you can enter '<boot image name> single' to place linux into single user mode. This does not bypass the login requirement.

You can configure the system to boot without offering the LILO prompt.

The easiest way to bypass security on ANY computer
system is to have physical access to the hardware. On Wintel boxes all you need to do is boot from a floppy. This works for all flavors of MS systems, and Linux.

Moral -- don't allow boots from floppies!

Mark
 
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Mark Blunier

> Just curious. It's "LINUX SINGLE", in all upper case, entered into
> the login prompt, without a password?

It depends. If the laptop using lilo as the boot loader, LINUX refers to the label used to identify which kernel to boot. This is typically
either LINUX, vmlinux, or zimage. Case doesn't matter. The names are set up in /etc/lilo.conf, and can be anything. This is useful for
booting different kernels. The rest of the lines are options passed to the kernel. Single is not a kernel parameter, so it gets passed from the kernel to the initial process, which is typically /sbin/init. Single tells /sbin/init to boot to single user mode, which usually does not require
a password.

> And is there a way of disabling this?

Change the init process so that run level 1 is not a 'single user' mode, but is set up as the normal run level (like 2). Also, make sure they can't boot from a floppy, or they will have free access to boot a floppy, edit the password files, etc.

Mark Blunier
Any opinions expressed in this message are not necessarily those of the
company.
 
K
> And is there a way of disabling this?

I'm not sure of the syntax of the above command (I would think it would be entered at the initial "LILO" prompt), but there are other ways to attack a Linux machine given physical access, including single floppy installations, sledge hammers, etc. The box has be physically secure as a first step.

--
Ken Irving
Trident Software
[email protected]
 
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Frank McNamara

For the last 3 years we've been installing ABACUS4 based process control systems (se http://www.abacus4.com). These range from paper machine control, to waste water treatement plant. We are commercial, and I expect you are thinking of Open Source.
 
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