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Curt Wuollet

Hi, all

Since I haven't been available for a few days, I'm just getting back in touch and thought I'd mention what I've been up to as some of you might be interested. Part of the delay is that I've taken over responsibility for robot programming at Heartland and I needed a reboot to work with Karel, it's like Pascal with predefined motion. I haven't touched Pascal for a few (ok, many) years, but, I did like it then. I like Karel less, but the tools have a lot to do with that. Anyway, on the same project, I am integrating pervasive Machine Vision to an automation cell we are building. The machine vision is based on the Video4Linux drivers and API and after some hacking, works rather well. We had the discussion and I can't release the actual application, however I can provide some pointers to hardware and software that works if anyone is interested. We are using it for measurement and pattern detection. I don't mind too much that I can't release the source, because Heartland is providing
some support for the Linux PLC and Westling has let me convert their entire IS operation to Linux. The integration experience will also apply to the LPLC over time.

I now have enough time to procure and look at the Optilogic Ethernet I/O. I'll probably get buried again soon after.

Hey, Hugh,

What the heck is "V"?

Curt Wuollet,
Wide Open Technologies.


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Curt Wuollet

Hi Jiri

This one is surprisingly high level and expressive for an automation tool. It looks
a lot like pascal with different punctuation. Var block, procedures, scoping, and yes, even variables. An interesting feature are conditions, where you monitor things and take action, I suppose on every scan. Almost multitasking. You still refer to I/O by short non descriptive labels like sdout[4] and din[13]. I haven't found a way to equate these to say, hold switch, or beer_tap except to wrap functions around them. They have predefined types like positions and functions like move along path [x...y]. A most pleasant respite from the lathe tenderbots that are essentially G-code machines. In fact the only more pleasant surprise I've had since I got
drafted into automation is GEF's State Logic. It just goes to show you that it doesn't _all_ have to be crude and nasty. I suspect that karel is a clone of ucsd Pascal, it even compiles to p-code. It's sorta like Turbo Pascal on my old CP/M machine. You get a taste of elegance, but you have to think small.

regards

cww

HEY GE, if you're reading this, State Logic on a Linux platform would be a "Killer Application" and would blow your other stuff right out of the water.

Jiri Baum wrote:

> Curt Wuollet wrote:
> > Part of the delay is that I've taken over responsibility for robot
> > programming at Heartland and I needed a reboot to work with Karel, it's
> > like Pascal with predefined motion. I haven't touched Pascal for a few
> > (ok, many) years, but, I did like it then.
>
> What!?!?
>
> Is this some sort of extension to Karel, or a retro-computing exercise?
>
> The Karel I know doesn't even have variables...
>
> Jiri
> --
> Jiri Baum <[email protected]>
> Windows is not popular. Windows is *widespread*. Linux is popular.


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Hi Curt,

I am interested in your comments about GE's state logic. I have not used it, but you obviously like it. Can you tell us a little more about it? What did you use it for? What was good about it...

Thanks,

Bill Sturm

----- Original Message -----
From: "Curt Wuollet" <[email protected]>
To: <[email protected]>
Sent: Friday, April 21, 2000 8:07 PM
> drafted into automation is GEF's State Logic. It just goes to show you that it
> doesn't _all_ have to be crude and nasty

> HEY GE, if you're reading this, State Logic on a Linux platform would be a "Killer Application" and would blow your other stuff right out of the
water.<


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Curt Wuollet

Hi Bill

The company I work for during the day uses quite a bit of State Logic. I am not directly responsible for PLC programming although I've read a lot of it and took a class in it. That's the most important point, it is readable and
makes sense to someone who programs is general computing languages. I can get what's going on much more quickly than with RLL. I have decided several times to do a project with it but, time pressures so far have dictated that we
outsource it to a specialist who has worked with us for years. I am a C programmer primarily, I have done Pascal in the past as well. I became a big fan of state machines because I do a lot of communications and protocol work and find them to be well suited for many classes of control work. State Logic is a "natural language" state machine description language. You can do the formal description as a state diagram and write code that is very easy to work with, even more "English like" than Pascal. Done right, even stuff you wrote a year ago is clear and lucid. That's what I liked about Pascal. It has other
advantages also, multitasking can be done reasonably. I'm not sure about electricians or the other people who supposedly benefit from using RLL, but anyone who has used a programming language could easily understand a well
written SL program. It's very much like pseudocode and being able to refer to the chiller valve as a chiller valve instead of q302 is especially helpful if you didn't write the code and the chiller isn't chilling. I think it's a big step in the right direction and much more appealing than most of the 1131 alternatives.
I prefer to write in C but, explaining that to a non-programmer is tedious at best. Almost everyone who sees a SL project says "I could do that" . That is a unique thing in my experience. Too bad they haven't pushed it more. I don't know why it isn't more popular either. It and karel are the only things I've seen from GE that I am impressed with, although we do have an install of CimplicityIU that runs a year at a stretch between maintenance. They won't sell that anymore though and the replacement didn't make it through the demo:^). Anyway, that's what I know, circumstances are conspiring in such a way that I will probably get a chance to do a project in it soon.

Regards

Curt Wuollet
Wide Open Technologies

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