adccommunitymod (AutomationDirect) asked a question.
Created Date: May 23,2014
Created By: csbc
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I need help with writing a program for Click PLC to run the keg washer I am building for my brewery. There is a similar thread in the Interface category. I would like to take that drum sequence and expand it. I understand a little about the software, programming, and installation, however I do need help. I need about 35 steps. (I can write what I would need done.) Would I simply create another drum sequence to put below the first one on rung 2? I will have 10 valves and 2 pumps to control. All 110VAC. I would ideally like to control a heating element in the cleaning reservoir using a PID as the main temp controller connected to the PLC so that when the cleaning reservoir pump turns on, it will turn the element off as to not dry fire the element. I have a few questions about the Click PLC and using a Cmore Micro with it. 1. Can the PLC have 4 different run sequences? (I apologize for my terminology, may not be totally accurate.) 1. Fill tanks, 2. Run clean cycle, 3. Empty tanks, 4. Passivation run on new kegs. 2. I do not understand the cmore micro software, totally lost on there. Essentially, I want to select 1 of 4 different sequences and press a start push button and let it go. Maybe I can achieve this using another screen or HMI? 3. What type of push button would start a run sequence on the PLC? I will start here and I really appreciate any help that I can get. Thank you so much.
Created Date: May 23,2014
Created by: csbc
Steps are as follows for Keg Cleaning Cycle:
User presses push button
1. Open Drain Valve
2. Open Air Valve for 10 seconds
3. Close Air Valve
4. Open Water Valve for 30 sec
5. Close water valve
6. open air valve 10 sec
7. close air valve
8. close drain valve
9. open detergent-return valve
10. open detergent-fast valve for 3 minutes
11. turn on detergent pump
12. close detergent-fast valve
13. open detergent-slow valve for 1 minute
14. turn off detergent pump
15. close detergent-slow valve
16. open air valve for 10 sec
17. close air valve
18. close detergent-return valve
19. open drain valve
20. open rinse valve for 30 sec
21. close rinse valve
22. open air valve for 10 sec
23. close air valve
24. close drain valve
25. open sani-return valve
26. open sani-fast valve for 3 minutes
27. turn on sani pump
28. close sani-fast valve
29. open sani-slow valve for 1 minute
30. turn off sani pump
31. close sani-slow valve
32. open co2 valve for 10 sec
33. close co2 valve
34. close sani-return valve
End cycle, wait for user to press push button again to start over.
Created Date: May 24,2014
Created by: AlbertL
That looks like an excellent application for a Drum instruction as you proposed, because the cycle is entirely controlled by time.
Created Date: May 24,2014
Created by: AlbertL
To address your first question: yes, you can easily have multiple independent cycles in one PLC program. You would probably want to include some interlocking logic so that someone could not initiate one cycle while another is in progress; e.g. pressing the "Clean " button while a "Fill " cycle is running. I don't know the cMore, but you can probably disable buttons under program control.
Created Date: May 27,2014
Created by: csbc
I think the easiest way to achieve this is with separate switches for each cycle. I would have 4 switches, 1 for each cycle type, then a start button to run a cycle. This would eliminate the cmore screen then. On the click software, how do I create a drum with that many steps? And how would I keep one step active while the next 2 or 3 steps become active? ie. turn on pump 1, open valve1, close valve1, open valve 2, close valve 2, turn off pump.
Thanks.
Created Date: May 27,2014
Created by: Bob S BN
I haven't used the CLICK line, but the EDRUM in DirectSoft5 looks kind of like a chart where all the steps are outlined in one side, and outputs can be assigned on the other side, including being on for multiple steps of the drum.
Use the last step of one drum to initiate a second drum to increase the number of steps.
Created Date: May 29,2014
Created by: csbc
I 've gotten much further the past couple days. However, I am still a little behind on the terminology. I have gone into this project and created the drum sequence I need. I have a few questions:
1. What does jog input mean and what does the jog do to this project?
2. What exactly does the C mean? I would imagine the C1 needs to be an actual input like a push button to start the project.
3. I want to have a safety switch attached to this. So, say Clean Cycle- switch 1 needs to be ON in order for the project to run when the Start button is pressed. How would I include that into this?
Thank you very much.
Nick
Created Date: May 30,2014
Created by: AlbertL
Regarding question 2: the C addresses ( "control relays ") are bits which are turned on and off by the PLC program itself. They are entirely internal to the PLC program - they are not linked to physical inputs ( "contacts ") and physical outputs ( "coils "). They are typically used to store the results of internal actions by the program. They can be controlled directly by Out, Set and Reset instructions, and by the results of instructions such as Drum and Timer.
In the program you posted, something would have to turn on the C bits at the appropriate time in order for anything to happen. For example, they could be turned on by an HMI in response to an operator action, or by rungs which use external contacts (X addresses) to control the C bits via Out instructions.
Created Date: May 30,2014
Created by: scott.lawrence
1. What does jog input mean and what does the jog do to this project?
Jog, in reference to the drum, will jog the drum through it's cycles, disregarding the actual inputs. I usually use it as a maintenance feature, to allow techs to simulate the cycle one step at a time
2. What exactly does the C mean? I would imagine the C1 needs to be an actual input like a push button to start the project.
The 'C ' is an internal bit. The term AD uses for internal bits, the 'C ', is for control relay contacts... although I haven't used Click software, physical I/O in the AD scheme is usually X for inputs & Y for outputs
3. I want to have a safety switch attached to this. So, say Clean Cycle- switch 1 needs to be ON in order for the project to run when the Start button is pressed. How would I include that into this?
Physical inputs are usually X (again, haven't used Click). Depending on the logic of the switch (NO/NC), you would place it as a permissive in the rung that starts/latches the cycle you want to control.
Created Date: May 31,2014
Created by: AlbertL
As an example, here's a version of your program modified to work with hardwired momentary-contact switches. The first four rungs link the PLC's physical inputs (X addresses) to the C addresses which you reference in the Drum instruction.
Although I made this change just to illustrate how internal relays can be used, some programmers recommend such mapping of physical inputs (and outputs) to internal relays as a good routine practice, because it allows you to easily change the program to match a particular PLC configuration.
For example, the X addresses in the program I posted might match the setup in your laboratory PLC, but in the actual machine, the switches might be connected to different X addresses. With this mapping technique, you just have to change the X addresses in one place, right at the top of your program. The rest of the program doesn't have to be changed, because it references only C addresses which remain the same. This greatly reduces the chance of a mistake.
Created Date: June 01,2014
Created by: milldrone
Steps are as follows for Keg Cleaning Cycle:
User presses push button
1. Open Drain Valve
2. Open Air Valve for 10 seconds
3. Close Air Valve
4. Open Water Valve for 30 sec
5. Close water valve
6. open air valve 10 sec
7. close air valve
8. close drain valve
9. open detergent-return valve
10. open detergent-fast valve for 3 minutes
11. turn on detergent pump
12. close detergent-fast valve
13. open detergent-slow valve for 1 minute
14. turn off detergent pump
15. close detergent-slow valve
16. open air valve for 10 sec
17. close air valve
18. close detergent-return valve
19. open drain valve
20. open rinse valve for 30 sec
21. close rinse valve
22. open air valve for 10 sec
23. close air valve
24. close drain valve
25. open sani-return valve
26. open sani-fast valve for 3 minutes
27. turn on sani pump
28. close sani-fast valve
29. open sani-slow valve for 1 minute
30. turn off sani pump
31. close sani-slow valve
32. open co2 valve for 10 sec
33. close co2 valve
34. close sani-return valve
End cycle, wait for user to press push button again to start over.
I copied and pasted this list into Excell so that I could visualize the requirements and translate it to the drum function. I found that it needed only 12 steps. Not the 34 the list implies.
One of your questions was about linking two drums together so I included a two linked drums routine also.