PLC logic

Greg, the numbers are just showing how the output lamp will be affected by the inputs. It describes how pressing a button turns on a lamp. Releasing the button then pressing it again will turn the lamp off. It describing a toggle operation.

I also suspect there is a typo on the third description since it should be the same as the first. When the finger is released the lamp should remain on.

Taelryn said:

Greg, the numbers are just showing how the output lamp will be affected by the inputs. It describes how pressing a button turns on a lamp. Releasing the button then pressing it again will turn the lamp off. It describing a toggle operation.

I also suspect there is a typo on the third description since it should be the same as the first. When the finger is released the lamp should remain on.

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I understand now them questions made it seem a lot different.

Just use Do-More Designer. Much easier that way.

geniusintraining said:

sczot, what is the value of the reset for the counter ?

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it's reseted by it's own output... so when it counts to 3 it will reset itself

Read the scope again, that would work for 1 and 2 but not 3

1) When we press push-button light comes on and we took off a finger from a push button and light stays on.

2) When we again press that same push button, the light goes off and when we take off a finger from a push button it stays off.

3) Again when we press a push button, the light comes on and when we take off a finger, a light goes off.

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DWF said:

Just use Do-More Designer. Much easier that way.

Click to expand...

Same that will not work for number 3

patelaksh30 Hi, and welcome to the forum. I like to see these homework or interview questions--when I'm not busy, keeps me sharp. I have a PLC on my desk, so I wrote the logic to do exactly as you wrote what they wanted--Push once and let go, light stays on. Push again and let go, light goes off. Push and hold, light is on, let go, goes off. Repeats like that indefinitely.
4 rungs. Everyone programs differently, and it may be "clunky" but it works. If someone gives me a restriction on how I write logic, then I don't want to work with them. I had to take a 1 hour timed test once, had to populate a rack, write logic, PID's, AOI's UDT's for a hot water pump process. I don't know too many people that could do all of that in an hour, and they told me one probably couldn't, but they just wanted to see how you think and how quickly you can get to a certain point.

Anyway, good luck with your job search. I wish you the best in your career. These pros on this site will help you but not do it for you. They have gotten me out of many a jam.

The way the OP worded the original post. There is the possibility of two push buttons.
One is a toggle, and the other momentary.

When I first started programing I did with counters and a lot of **** but it worked, I have even came across some of my old programs and get a laugh at what I had done. Now I use this alot.