Re: [CAD_CAM_EDM_DRO] PLC's and industrial automation

Dough
some moer info?
I agree most plc´s are simple 70's stuff but much cheaper
than in yhose days.

Sven Peter

Doug Fortune wrote:

> Doug Harrison wrote:
>
>> Try www.automationdirect.com and look for the DL-05 or DL-105. The 05
>> starts at $99 and the 105 at $149. I got the software for an additional
>> $99, though I think its now $199. AB, GE, etc are often available in the
>> dumpsters but the software will kill your bank account if you have to buy it.
>
>
> OK, no-one has said just what the darn things are! Just a quick overview
> please. Is it just a little loop logic and input/output relays?
>
> I'll give you a counter-example: A Scenix (now Ubicom) SX-28
> programmable microcontroller chip:
>
> http://www.ubicom.com/hardware/sx28ac.html
>
> programmers available (~$200 range) from:
> http://www.parallaxinc.com/html_files/sxtech/sxtech_home.htm
>
> It gives you 20 I/O (dedicated or multiplexed), analog in & out,
> and 50 or 75 MIPs (millions of instructions/sec). If you prefer
> not to use assembly, there are C compilers (at least one is free).
> I have one very complex program that is 35 pages long, and am
> still only using half the ROM! The chip is only $5.
>
>
> The SX-52 runs at 100 MIPs and has 40 I/O pins, and twice the
> ROM storage. This chip is around $10.
>
> - - - -
>
> I am assuming the PLC's have no where near this sophistication,
> so unless someone tells me otherwise, I am still going to assume
> PLC's are 1970's technology, and it is more worthwhile to spend
> time learning something new ( like high performance microcontrollers)
> vs something old (like PLC's). The only two advantages to PLC's is
> perhaps that they are field programmable & integrated with high current
> drivers - but really that is no different than putting some relays and
> programming pins on a little SX circuitboard.
>
> ....unless I'm way off base, of course.
>
> Doug Fortune
> http://www.cncKITS.com
>
>
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