can anyone help

Hey I'm just starting to learn rslogix500 and I was wondering if I could get some help. I have to write a program to install a red light and buzzer. If out of the last 10 parts made 5 are scraps, then the red light and buzzer go off alternating. Also the press has to shut down. The PLC is new and has no outputs or inputs so any can be used. If anyone could help guide me and give me some tips that would be appreciated. I can be emailed at [email protected] also. Thanks.

Sounds to me like you need an up counter, a down counter, and a bit shift instruction. Since I'm guessing you're a student, I'm not going to offer anything more than that. Read up on those instructions and you should be able to envision how they could be used to do what you want.

BTW, let's keep the discussion on-forum so that the maximum number of people can benefit from the discussion. No private consultations without a purchase order.

The SLC500/Micrologix 1000 Instruction Set Manual can be downloaded at:
The Automation Bookstore

purduedb....hmmm sounds like a student email..ie doesnt Purdue have a decent basketball program? It seems they also have a very intense Engineering program: https://engineering.purdue.edu/Engr/Academics/

As was stated many here need/want to be paid if they are to do the programming. You are expected, even if working in an industrial position, to make an effort to create a program.

BTW I have never seen a PLC without inputs or outputs...oohh I see you have no input or output devices connected to it. THE first thing you MUST do is determine what input devices are available or need to be added to accomplish this task. Since all you need to in this application is trigger a light a buzzer and shutdown the press its kind of obvious what the outputs are. The shutdown could involve a relay or relay output that is NC...if you arent a student you will understand this part, like a ESTOP interlock.

Lets see if I cant give you some bad advice that may get you thinking on good ways to do this. It seems you have to be able to "count" all the parts and the bad parts then do a COMPARE of the last ten, this could take a little thinking because you want to look at ten items at a time and if out of that ten five are bad do the alarm/shutdown. That could require some form of a register that holds the number of good parts and bad parts that get shifted.

I aint that good so maybe you could show me how this could be done, I an intrigued.

Mattbdb,
I, like everyone else assume that this is a student assignment. This site has a history of ensuring that students do their own work and not get the members here to do it for them. But I’m going to assume that you are not one of those and that you are looking for a place to start.

You must break these types of problems into smaller parts. The first key to your problem is counting the work.
1.Build a counter that resets itself every 10 parts.
2.Build another counter that counts bad parts. Use the reset of counter 1 to reset both counters.
3.Once you have the counters working the way you want try making just the light come on when the proper number of scrap parts is reached.
4.Now that all of that works, make the buzzer alternate with the light.
5.Finally add the interrupt for the press.

Once you have everything working go over your design and find ways to make it better. Once you get some experience with programming you will be able to look at a problem like this and know how you can do 95% of it before you ever start programming. But for now don’t be too worried about the whole operation. Just make one part work, then another, and another until you have a total job.

Good Luck

KMG if you re-read the post and your solution you will see it wont work. The idea is not to look at 10 parts and see if 5 are bad, its to look at ALL parts and see if 5 out of 10 are bad. There is a difference.

Using your scenario you would look at 10 parts at a time, what about those situations where 10 parts are made and the last 2 are bad, then the next 10 are made with the first 3 bad. That would be a situation where 5 in a row were bad but didnt trigger the alarm.

I think Steve has given the best advice so far, I just added mine to invoke a response.

Yes, I know what the objective was. As I said, it's a starting point. And I also said after the work is done to go bad and improve the design. Steve's Idea is the way I would do it, but I wanted to give him an outline to follow. When I read the post I though that he was over thinking the problem and I felt a general outline would be useful.

No I/O plc?

I am surprise if we use plc without I/O..
However,we can do with plc simulation program such as Logixpro..
Gpp for Win.. Automation Studio...and.. etc

In this case...If you need help ..
Try to do by yourself first .. if can not then try..plcs.net

Do Good received Good ..Do Evil received Evil..

A.Char

Acshully, I wouldn't do this hyar with a counter 't all. I would use 11 registers, 9 moves moves, addition, and wun compare.