RSlogix - Bottling Plant

Hello Everyone, thank you for taking the time to read this post.

I have the following problem for a Bottling Plant program.

The description is within the program file... please feel free to comment and have a look.

Much appreciated,
Cheers!

The description is within the program file... please feel free to comment and have a look.

Click to expand...

I did look, and made comments and changes. They are within the program file Revision 7. The changes are marked by the "eee"'s next to the Rung number (for Edited but unVerified rungs).

One recurring question is "does your material-handling devices finish their operation in 0 seconds"? Several places in the program, you activate a device, then immediately AssUMe that the operation is finished in the very next split second on the very next rung. That rarely happens in the real world. The only case where that happens is when you activate something like a solenoid valve that only has to pop open in about 0.25 seconds. Another instant case is where your logic only has to START a device, and it has all the built-in limit switches and logic to run until it is finished. Most other devices, such as air cylinders, require some amount of time, 2 or 3 or more seconds, to operate. That is something to think about and check to make sure that you have it covered in your logic.

PS: Normally, a OSR is not needed with a Counter trigger. The counter effectively has its own built-in OSR, only counting 1 time for each Off-to-On transition.

Hi Lancie, thank you for your valuable corrections. I did the modification and added a new timer before the reset to let time for the stacker to conveyor #3 to operate.

I understand the delay needed for the different component of the bottling plant.

Let me know what you think.
Cheers.

I only saw one thing, but there could be other problems. On Rung 0003, I think you need to use a XIO for OP3, because you want the Filler Piston to be OFF again, AND IP1 seeing a high level, before you start timer T4:0.

Got it. Thanks

This is a response to your comment:

Could a XIC contact for CT2/DN be added too here to be consistent (like we have on rung #0010)?

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Remember the instructions: “When 9 bottles are on the stacker it will operate the piston OP7, which lowers the stacker platform to conveyor 3 as shown in the stacker section of the FIGURE 6. “
You could immediately reset C5:1 only IF the stacker can lower the 9 bottles INSTANTLY to Conveyor 3. Maybe that can happen in this simulated version, but if it is “real”, the stacker will need SOME TIME > 0 to lower the stack.

If you reset C5 :1 as soon as it counts 9 bottles or 3 stacks, then the stacker could drop the bottles onto conveyor 3, breaking all of them, or maybe it will not release the stack at all! In both cases, there would be a big jam and a big mess in the floor with spilled liquids! I think it best to wait some time period to allow the stacker time to do its job, before you reset and make it start over.

Your next question then might be: How can we reset the stacker count immediately to allow the process to continue, but still allow the Stack output to be held ON for some time period greater than 0?

Here is one way (see attached revisions to Rungs 0012 through 0015) to allow both counters to be instantly reset (by sealing in the various timers and outputs until they are finished).

In other words, use the Counter Done bits to START the next step, but use something else to STOP the next step. That is a common progrmming method. Often a process must be stopped by something other than the same device or input that started it off. By doing that extra, you could then reset both counters during the very same PLC scan that their DN bits turn on.

That may or may not actually be necessary, depending on how your simulator works.

Got it. Thanks