Car wash blues

[howardc69]

I am looking for a little critiquing on my car wash ladder logic diagram that isn't working that well. As well as I want to put in a door program which i have just not sure where to insert it and lights as well.View attachment Howards car wash02.zip Thank you in advance for critical advice. Howard

 

[Lancie1]

For your 4 Wash modes, you use the instruction "T4:x.ACC Less Than or Equal yyy", for each of 4 timers. What you may not have thought about is that when a timer is not activated, the Accumulator = 0. That means that all rungs that use the LEQ instruction will be active, even when they should not be. You need to fix these problems by using your Mode Enabled bit in front of each LEQ, as shown in the attached revision "Howards Car Wash 03". An alternate fix would be to use "T4:x.ACC Less Than or Equal yyy" AND T4:x.ACC Greater Than 0" in place of the LEQ instructions.

Apparently most of your rung comments and symbol comments got deleted when you ZIPPed your file, so I tried to figure out what they should be and reentered those as needed. I organized the rungs by the 4 operational modes: 1 Wash Only, 2 Rinse & Wash, 3 Wash and Wax, 4 Rinse, Wash, & Wax.

Where is the door, at the entrance or exit? If entrance, put it before the Mode 1 rungs. If at exit, put the door after the Mode 4 rungs and before Outputs. For lights, if you want to indicate each Mode, use the Mode "B3:0/x" mode relays to trigger a light for that mode. You could put the light Output in a parallel branch with the Mode relay. For a light for Pump, Blower, Brushes, ect, put the light in a parallel branch with each device output.

 

[howardc69]

car wash blues

Okay that is really helpful, thank you. I opened the pdf and it disappeared. the door is at the entrance and when finished washing activated at the beginning of the blower. Howard

 

[Lancie1]

Which output are you using for the door motor? Does the door have to open to let the car into the wash? How long does it take for the door to get from closed to open? What inputs are your Door Open and Door Closed Limit Switches? (Probably also need a photo sensor under the door to make sure it does not close on a car).

I opened the pdf and it disappeared.

I don't know why it would disappear. I can open it and read all 6 pages. Initially I tried to post the PDF without zipping it, but it was too large. Maybe you tried to open that first copy (that I had to delete).

 

[howardc69]

car wash blues

Okay that is really helpful, thank you. I opened the pdf and it disappeared. OK so do I enter the whole door command at the beginning and the end? Since I have the door opening upon coin activation and closing once car is in side and again opening after wash complete going towards blowers. That would add 10 more rows to the diagram. Here is what I have as a program:
hopefully their is something smaller that wont cause me to go through and change my in/out addresses to much.

 

[Lancie1]

You already used O:2/1 through O:2/5. I suggest that you make O:2/6 Motor Up and O:2/7 Motor Down, followed by the 3 door lights in sequence.

O:2/6 Motor Up
O:2/7 Motor Down
O:2/8 Door Ajar Light
O:2/9 Door Open Light
O:2/10 Door Closed Light

I:1/0 Coin Switch (also now serves as Door Open PB too)
I:1/1 Vehicle Sensor
I:1/2 Door Stop PB
I:1/3 Door Open Limit Switch
I:1/4 Door Closed Limit Switch

After thinking about this addition, I would make it a separate section after all the current rungs, to prevent confusion about how the system operates. An option would be to make the Door rungs a new subroutine Lad 3 file called "DOOR", called with a JSR instruction as the last rung in the Lad 2 file.

 

[howardc69]

car wash blues

Well looks like I'm going to have to go back to the drawing board, i didn't include a total vehicle counter and need to add a master reset. when I'm done I'll re post for another critical look, thank you the lights at the mode worked great easy fix that i am surprised i didn't think of. Unfortunately no subroutines allowed on this project, it would have made it a lot easier to do, so i have to incorporate them in the main diagram.
I originally had inserted the door program at the end but wasn't happy with the results since it's so long i didn't feel it was working right, or i could be wrong.

 

[Lancie1]

There are some bits you have to add to make the door:
1. Open when coin deposited, then
2. Close when Vehicle Sensor goes on for 1 cycle (use One Shot OSR); then
3. Open when Blower first goes on (use another one-shot); then
4. Close after Exit when vehicle sensor goes off (use 3rd one-shot).

In other words, your Entry/Exit door will have to make 2 complete round trips up/down, up/down for each vehicle.

I can give you a suggested addition for the above, if you want it.

One thing to know is when you get many symbol descriptions in LogixPro, it starts deleting some of them when you do a Save. In other words, you can put them in, but they will not be there the next time you open the program! It is really an aggravating bug. I think it has to do with the amount of memory that LogixPro allocates for symbol descriptions. One thing you can do is to delete all the unused symbols. In RSLogix500, that is easy to do, but in LogixPro, the only way to delete an unused symbol is to add the address on a temporary rung, then delete the symbol description, then delete the temporary rung!

A Vehicle Counter and Master Reset should only require 2 more rungs.

 

[howardc69]

car wash blues

Any suggestions are defiantly appreciated. I was actually thinking of using osr but was so wrapped up in all of the requirements for this project i forgot the simple things like adding a door program, it wasn't neccasary but most car washes i go to have the door for bad weather and traffic control so i wanted to put it in their. A suggested addition would be great thank you. Yes I've noticed the problem with saving, and actually some of my saves end up getting corrupted and changed as im scrattching my head as to why its not working lol
Howard

 

[Lancie1]

Here is Revision 4. I tested the door part and it seems to work, with the Limit Switches Normally Open and closing when door is Up or Down. The "1" in the Vehicle Counter C5:1 Accumulator was for when I tested it. To Reset to 0, press the I:1/5 PB while in RUN mode.

 

[howardc69]

car wash blues

That is awesome, and fast thank you very much, hopefully one day I am as adept at programming as you are. When i tried to tie it in at the end it didn't work well, i like how you tied every thing together seamless execution thank you for the over the top assistance, any thing you need that i can help with I'm here.
Howard

 

[Lancie1]

No problem, I was glad to help.

EDIT: If you need a manual OPEN PB for the door, you can add a button with the next unused Input address (I:1/6) for that on Rung 38 with another parallel bit with the 2 existing Door Open triggers.

...hopefully one day I am as adept at programming as you are.

Copy (Ctrl-C), Paste (Ctrl-V), and Edit (click to highlight and type) are what makes me faster!

 

[howardc69]

car wash blues no longer

Thank you.

 

[howardc69]

car wash blues

OK, so on the total coin counter( Line 00 CTU C5:0) which RES should i delete to be able for the total coin counter not resetting each time the cycle is complete? So that i can have a total coin count.

 

[Lancie1]

OK, so on the total coin counter( Line 00 CTU C5:0), which RES should I delete to be able for the total coin counter not resetting each time the cycle is complete?

If you delete any of those C5:0 Resets, then your program will no longer work correctly. The way you set it up, the logic depends on being able to count the coins from 1 to 4 EACH WASH in order to figure out which type of wash mode to enable. If you count higher than 5 (with C5:0) before resetting C5:0, your logic no longer will work.

Now, the way to get a total coin count is to add another counter C5:2. Place the Coin Counter on Rung 000 in a new parallel branch with C5:0. Rename the old counter C5:0 to something like "MODE COUNTER" (that is what it really does), call the new Counter C5:2 something like "TOTAL COIN COUNTER". Then reset the new counter ONLY when the coin box is emptied, or you want to manually reset it with a pushubtton. One way is shown in the attached picture for Rungs 0 and 1.

PS: The reason to set the counter Presets to no more than 32767 is that is all that a real RSLogix 500 counter can count to (15 binary bits 0 to 14 max - last bit 15 is used as a sign bit). LogixPro will allow you to put in a much larger 14-digit decimal number, but you should not because in real-life programs you will not be able to do that using RSLogix.