Logixpro Batch simulator

[Lancie1]

In the last part (Switching Modes A B C) i'm completely lost what should be done to achieve the desired work in each Mode.

You need to do Steps 1 to 4 as noted on the attached file.

You need to set up your logic correctly so that you can stop all Outputs by turning OFF Output O:2/5 SYSTEM RUN. Then use an Auto-Stop relay to shut off O:2/5 when either Selector A or C is on. For the continuous running "B" position, you need to have the logic so that it automatically repeats after the drain step, unless the new Auto-Stop relay is activated. That way you do nothing when Selector B is ON. It becomes your default setting.

 

[Glendoor]

Help with PLC Project

Hello, new here and looking for some help. I have a project that I am having a bit of trouble getting to work. Well the main problem is getting my program to run one cycle when the selector switch is in position A. Everything else works as it should according to the instructions I was given, just having trouble getting one cycle to work. I tried using the example Lancie1 gave in regards to using an auto stop bit however I can't seem to get the logic to work in my program. Any help/advice is greatly appreciated.

 

[Lancie1]

Any help/advice is greatly appreciated.

I see a few things that I would use to reduce your homework score.

1. No rung comments, a sure way to knock off 10 points!. This indicates that you do not know how the program works, and do not understand what each rung is supposed to do.

2. Rung 001: you do not need the parallel branch with I:1/3 Low Level Switch. This is a binary case of either ONE, or the OTHER, but never both. The Batch Simulator is either in RUN mode, or it is not in RUN mode. If it is NOT in RUN mode (O:2/5 RUN Lamp is OFF), then it is in IDLE mode and O:2/6 should be ON. There should be no other conditions for O:2/6 other than NOT O:2/5.

3. You have your steps jumbled up and out-of-order in the program. That makes it hard to follow your non-logic. Put them in a logical order: Step 1 FILL, Step 2 MIX, Step 3 HEAT (apparently, but the original LogixPro exercise calls for heating before mixing - resolve this conflict), then LAST should be the Step 4 DRAIN.

As is, you program cannot operate. Rung 10 causes it to halt as soon as the tank is full, because the tank starts off empty and the Low Level Switch I:1/3 is ON, latching your flag B3:1/3 TANK EMPTY. That immediately causes rung 14 to activate the B3:1/4 Manual Bit, which stops the system.

I will attach a corrected version of your program, as I think you meant it to work.

 

[Glendoor]

Thanks for taking the time to go through my program Lancie1. I ended up figuring out the code I had to put in on the last rung to get the stop bit to work. I will be adding in rung comments, my program was a bit of a rough draft when I posted it. The program was a custom thing my instructor wanted us to do, it wasn't part of the logixpro examples or anything like that. There is this timer I had to put in so that the cycle would'nt start until it was idle for 2 seconds. So it's a bit different then what the examples wanted but it did give me a good reference to go by.

I will take your suggestions to heart and clean it up a bit. Thanks again for the help, really appreciate it.

 

[Lancie1]

I will be adding in rung comments, my program was a bit of a rough draft when I posted it.

That is exactly backwards. First think about what the next rung needs to do, then write a comment that describes that and nothing more. Only then are you ready to write the rung logic - after you write the comment that serves as your rung road map!

There is this timer I had to put in so that the cycle would'nt start until it was idle for 2 seconds.

So that is what T4:2 was SUPPOSED to do! You were a long way from having Timer T4:2 cause a 2-second delay at the BEGINNING of the cycle. You had it somewhere in the middle after the tank was FULL, not while it was still empty.

The attached picture of the revised first 3 rungs shows a 2-second delay at the beginning, after the Start PB is pressed (and the RUN Relay & Light are ON).