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Microcontroller Programming » programming ladder logic

January 10, 2011
by mrkvickasteve
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this may be outside the relm of your beliefs but what do you guys think of programming in ladder logic? I would like some professional input on this subject before I get started. I found this software at

http://www.filetransit.com/download.php?id=60935

and was wondering if anyone tried it. I only ask because I used to program allen bradley plc's and would be able to understand that a lot more than "c" but I dont know if I would be able to write to the lcd in some of your projects but for a simple machine this may work well if it is all compatible with your chips, Steve

what do you guys think

January 10, 2011
by tomroth
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Ladder Logic is for PLC's, not micro-controllers. PLC's are really a bunch of relays that can be controlled via programming as opposed to rewiring. There is in no way any compatibility between the PLC and the Nerd Kit MCU. Now, while Ladder Logic is a much simpler way to program than in C, (I am learning C as well), it just won't work with a micro-controller. Sorry if that makes life any more difficult, but I had to learn assembly and Ladder Logic at the school I graduated from in December, I guess you will have to learn C.

Tom.

January 10, 2011
by SpaceGhost
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I have done ladder logic programming too with Allen Bradly PLCs. I have an AB 16 bit PLC, (Micrologix L16BWA) that I bought off ebay back back when I took a class on PLC programming at the community college. I use RSLogix lite (freeware) at home, compatable and nearly identical to the full version (expen$ive) that the school used.

I enjoyed ladder logic programming probably because I already had a fairly good understanding of electrical prints. PLCs were part of an electrical maintenance program I had been enrolled in. I liked that part of the program (PLC part was only a couple weeks) while most of the other guys hated it. I liked PLCs so much that I enrolled in a full semester advanced PLC class the next semester. Got an A, tied for top of the class!

I understand ladder logic programming waaay better than this C stuff, but I really want to learn. What sort of site is it that you cited? Is it a file sharing site? You gotta be careful. What is the actual name of the software that you are referring to that is downloadable from that site?

January 10, 2011
by mongo
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I too use the AB RSLogix as well as several others. Big difference between them and the NK environment. These little kits are more for the embedded programming that you can use to build purpose specific devices. A great educational tool that can be built into a real permanent circuit if you have a need for something like that. They are also great for learning C code as well. By doing, learning is achieved faster than by not doing.

January 10, 2011
by SpaceGhost
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I kinda agree with Tom also. I'm doubtful one could use a ladder logic type program with microcontrollers.

January 10, 2011
by bretm
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But....that's exactly what this software claims to do. It generates code for PIC16's and Atmegas. I don't understand what it's doing, but it looks like it generates a framework of the ladder-based application that calls down to specific hardware I/O routines that you have to supply, but it looks like that part would be mostly the same and reused across multiple apps.

It looks like wiring formulas together in a spreadsheet and the LDmicro app figures out what needs to be calculated in what order to satisfy all of the dependencies. It produces a function that needs to be called periodically in a main loop at a specified time interval.

January 11, 2011
by tomroth
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If you get down to the nitty-gritty, all programming could be loosely compared to Ladder Logic. A relay is on or off, a 1 or a 0. All programming is controlling specific bits to achieve some desired outcome. But in actual programming in such languages as C and others, far more user interaction can be achieved. Getting changing variables and the like into Ladder Logic isn't as simple and user friendly as having a computer screen in front of you asking you if you want degrees F or C, typing in the choice, and then having your results displayed. Ladder Logic and PLC's are desinged for industry, and do it quite well.

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