From: Don Pearce
Subject: Re: Avoiding PLCs
Date: Thu, 17 Oct 2002 10:10:39 +0430
References: <email@example.com> <firstname.lastname@example.org> <email@example.com> <2jqr9.76172$oq6.18550@sccrnsc01> <firstname.lastname@example.org>
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On Thu, 17 Oct 2002 04:26:21 GMT, email@example.com (Mike
>On Thu, 17 Oct 2002 13:56:53 +1000, "Cameron Dorrough"
>>And that's one of the *best* reasons not to use custom PC's with custom
>>software right there..
>>If the PLC ever needs to be upgraded/replaced, simply translate the existing
>>ladder logic, PID loops, etc to the new platform. It is very easily done
>>(especially something like Siemens to AB or vice-versa).
>>Heaven help you if your plant is reliant on custom PC software written for a
>>particular (eg. Microsoft) operating system that is no longer supported, on
>>a PC chipset (eg. x86) that you can't buy parts for.. That's just asking
>>for trouble. Been ther done that.. remember DOS? ;-)
>Yep. And we should still be using it for any kind of control
>system running on a PC. By version 5 and 6 it was/is
>pretty stable and has all the features we need.
Remember Dr DOS? Now that was the one to use in my books. I had a PC
with that on it until very recently.