PLC Parking Garage Program

[SandwichMagic]

So, we know that our outputs are working now! that is great. Now we just have inputs to deal with. So I am not familiar with AD's programming software, I imagine that the UDC is a counter? and the third rung is meant to clear it, yes? If so that all looks fine. The reason why the light is always on is in Rung #3. You have a set of comparative contacts which compare the status of the counter (I think) with 23, and those contacts close when the status of the counter (I think) is less than 23. The problem is that this is your only instruction on that line. It doesn't care whether you have hit the start button or not, you haven't told it to. All it is looking for is whether the counter is less than 23, and when you first turn on the PLC, it is 0, which is less than 23. You can remedy this by putting in a XIC tied to X1 as the first thing in rung 3.

Edit: Forgot to mention that you would need to add the same thing for rungs 4 and 5 as well, when you get your inputs working, the red and yellow lights will also not care. as a side note as well, I don't know how much turning the program "off" in this manner will help maintenance, I suppose you could ensure that power wont go to your lights but that's about it.

For your input problem, this link (http://www.automationdirect.com/static/manuals/d0user/ch2.pdf) is a link to the installation manual for your PLC, the inputs are on page 28 of the pdf. The diagram from the manual for your plc is on how to wire the inputs correctly. The manual says that you can wire it sinking or sourcing, so it doesn't matter if you decide to do it sourcing.

 

[CraigY49ers]

Parking Garage program

Hello Everyone,

Okay, so i fixed the third rung by adding the XIC "X1" in the rung before the compare instruction. But you said that I need to add an XIC to both rung 4 and 5. Did you mean that they should both be tied to "X1" or "X2 and X3"? I am not sure if that is what you meant?

Sincerely,

Craig Yarges

 

[SandwichMagic]

In retrospect, I am actually a huge dummy, and it should be an XIC addressed to your internal coil, C0, on rungs 3, 4, and 5. Essentially with this instruction, you are telling the program not to fire the output unless it is in run mode. For some reason i thought that X was your bit and not your inputs, oops, sorry about that one.

 

[CraigY49ers]

Hello SandwichMagic,

Thank You for clarifying that for me I am so tired I am having trouble concentrating but I must go on. I really appreciate the help and will fix that problem right now and get back to you in a few minutes.

Sincerely,

Craig yarges

 

[SandwichMagic]

not a problem! You shouldn't have too much more from the looks of things.

but of course, that is the last thing you hear before more problems occur! *knock on wood*

 

[CraigY49ers]

Parking Garage program

Hello Everyone,

I have updated my program to include the XIC instruction in the other rungs that did not have it yet. I am going to try and run it now and see what is happening I will post again right after I try the program and see what happens. Thank You for your help. Here is what my program looks like now.

Sincerely,

Craig Yarges

 

[CraigY49ers]

Parking Garage Program

Hello everyone,

I have saved and downloaded the program to the PLC but when I try and run it now I get no lights at all. It does not turn on with the green button or count up or down with the others or reset. I will have to go back and look at the contacts I entered or I do not know what else to do at this point. I am a little frustrated but I am not giving up. If anyone has a comment I would definitely like to hear it?

Sincerely,

Craig Yarges

 

[SandwichMagic]

Did you fix your inputs yet? did you set them up how the diagram in the pdf I linked to you has them set up?

 

[CraigY49ers]

Parking Garage Program

Hello everyone,

Yes, that is the document I used when I wired them and when I rechecked them tonight. They are wired just like the diagram shows but I just cannot get the program to run now. When I download it to the PLC and run it does nothing when I press the buttons now. Not sure what is up with that? Here is a copy of what it looks like now.

Sincerely,

Craig Yarges

 

[CraigY49ers]

Hello Everyone,

I am going to have to go to bed and start fresh in the morning because my back is starting to hurt. I will be back at it tomorrow working until I get it right. I have to demo it tomorrow evening at 5:00pm Pacific Time Zone. I have no Idea what I am going to show them though? I will do my best and show them how it is suppose to work. Thank You for the help and encouragement and I hope to hear from you tomorrow. Please email me if you see anything wrong with my program? Or if you can think of something I did not.

Sincerely,

Craig Yarges

 

[SandwichMagic]

To your program:

The only problem I immediately see is that your counter will constantly be reset. The instruction in front of your reset should be a XIO on your stop, X1. This way it will reset when you press the stop button.

Once you get that going, now the light being on is dependent on your inputs, so if you cant use your inputs, then you cannot fire any outputs. So just to double check: from your power supply, you have your negative going into the common (c0), then you have your positive going into EACH top side of your buttons, and you have a wire going out from the bottom side of each of your buttons, but each button's bottom side wire goes into a different input on the plc. This is how it should be wired. This is a sinking configuration.

 

[CraigY49ers]

Parking Garage Program

Hello SandwichMagic,

I have the power supply wired to the PLC and then I have one side of my switches wired to the PLC and the other side wired together with the positive side of the power supply. That is what it shows in the manual did I wire it wrong?

Sincerely Craig Yarges

 

[SandwichMagic]

What is going into your C0 Terminal?

 

[CraigY49ers]

Parking Garage Program

Hello SandwichMagic,

Here is my updated copy of my program as of right now. I fixed the reset now I think did you think that I wired it wrong? I did it just like it pictures the positive wires all connected to the same wire. If it was suppose to be different I messed up because I thought that was right. how else would you connect the four switch wires to the same connection?

Sincerely,

Craig Yarges

 

[CraigY49ers]

The main C0 is the wire that I ran from one side of the switches to the PLC.