LogixPro Compressor flip flop ladder logic explanation. Details about how the OSR is used to flip

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LogixPro Compressor flip flop ladder logic explanation. Details about how the OSR is used to flip

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Күн бұрын

I go into details about why the OSR flips the bit that controls which compressor is used. When you watch this logic in real time as the system is running, it's hard to understand why this works. Here I slow it down to one scan cycle at a time to explain what is actually happening with these bits and why. It only makes sense if you can understand the order in which Allen-Bradley evaluated the different parts of the logic.

Пікірлер: 7

@austinlay4085 Жыл бұрын

Thank you for this explanation

@DJRY360 2 жыл бұрын

I used this in the traffic lights with delay to achieve the sequence with only four timers, however even at high scan rates there is a noticeable blip in the middle of both reds being on, the moment where the cascade resets. there are no lights on briefly and every now and then a car slips through. is this just a result of the simulation or is this a poor way to do traffic lights? basically my logic is: four timer cascade (10,80,40,10) >>> osr flipflop >>> logic for light outputs based on timer TTs and direction controlled by flipflop thanks for these videos, they have been a big help for me :)

@hanarobinson6738 3 жыл бұрын

Hello is there anyway to make rungs 5 & 6 without the use of the OSR?

@elmeonline9932 3 жыл бұрын

There are certainly other ways to make the compressors alternate. This is the first solution I thought of using only the instructions available in the "bit" tab. You could use a counter that increments 1 count for every switch of PE1 and have one motor operate when the counter ACC is even, and the other motor operate when the ACC of the counter is odd. There are other more advanced functions you could use for this job as well, but my interpretation of the instructions was that you're supposed to use the most basic instructions you can.

@iliapopovich Жыл бұрын

yes. I used 2-bit latch.

@iliapopovich Жыл бұрын

@@elmeonline9932 Counter isn't allowed. You need just relay logic and even OSR isn't a professional solving to the problem. If you have an email I can send it. It took me some hours to do it by the way.

@iliapopovich Жыл бұрын

I guessed could do it with a flip-flop, but used a similar latch based on a 2-bit relay counter(not the CTU instruction) because using OSR isn't allowed. It's the same result with about 40 inputs. Actually, this job could be done only with 5v-220v relays and push buttons.