How PLC's (Computers) work at the fundemental level

Calscada

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Mar 2022
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California
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I posted how computers work at the fundamental level on Reddit if you want to check it out. Pretty fun stuff and thought I would share it here as well.

https://www.reddit.com/r/PLC/comments/trn3kq/lets_go_down_down_down_inside_the_plc_processor/?utm_source=share&utm_medium=web2x&context=3

The main point is to check out all the pages from Jeroen Brinkman's MERCIA Relay Computer https://www.relaiscomputer.nl/

And this simulation of an old 6502 processor! you can zoom in and hit the play button to see the transistors firing.http://www.visual6502.org/JSSim/index.html

Check out the main visual6502 site to see more simulations http://www.visual6502.org/

Decoder Circuit from the Relay Based Computer
ConditionDecoder.png
 
Hahaha, yeah, usually. We use the kiss method. Even though you can do hardcore computer science stuff in structured text
We try to keep it simple as possible.
 
None of those explain why an "efficient compiler" is the "pinnacle of computer science", much less what the term even means.

Does the compiler being efficient at anything determine whether you can implement parsers, kernels, or neural networks?

Oh, I misunderstood; I was under the impression that computer science is more than just compilers.

When talking about computers, compilers convert a high-level language into something the processor can run called machine code (“.EXE”). So, for example, 20 lines of high-level code could blow out to 1000 lines of machine code on an efficient compiler, compared to those same 20 lines of high-level code blowing out to 100,000 lines of machine code on an inefficient compiler. More code lines will lead to more instructions for the same task, thus running slower. In addition, the conversion from high-level to machine code loses the ability to edit the machine code in a high-level language. The same is valid but different in photoshop or AutoCAD; you can have an editable file, but once published as a PDF, you lose the ability to edit the layers and objects when using the PDF. I stated it's the pentacle of computer science; I either read it in a textbook, a teacher told me that, or smoked too much.

PLCs are different, and to the best of my limited knowledge of the inner workings, Studio/RsLogix, and step 7 are specialized visual editors/aids/error checkers? Both the visual editor and the PLC firmware can interpret the PLC program. To the best of my knowledge, the firmware translates the High-Level user program into something the PLC processor can execute, like Accept/Test/Assemble in RsLoxix 500, Thus giving the ability to upload/download PLC programs in their original form while being able to run user program.
 

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