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Hot Glue in Tray Former - Timing/Waiting/Gluing question

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  • Hot Glue in Tray Former - Timing/Waiting/Gluing question

    I'm recomissioning a machine that folds boxes around 24 cans of beer (4x6-pack or 6x4-pack or 24 loose, or 2x12-packs). The machine was purchased at auction and the HMI was shot, one of the two PLCs was shot (B&R) and the second (AB SLC 500) had a dead battery and no EEPROM - so no program. /backstory

    I've installed a P1K and connected all the necessary sensors and some outputs. The machine is mostly mechanical - turn on the main motor, and the drive chains do 90% of the work. I need some logic to tell it when to shoot glue onto the flaps, that then get folded mechanically.

    I'm looking for some help on how to accomplish this. We're only running it at one speed - 15% faster than the canning line runs at, or a case every 7.5 seconds. Based on that, I've measured the distance between the sensor and the glue nozzles, and then a pneumatic arm that presses the flap onto the hot glue. I did some basic math to then tell how long it needs to wait until it shoots glue, how long to shoot glue, how long to wait until the second flap, how long to shoot glue again, another wait, and then pressing the flap assist. The breakdown is below...

    Here's what I need to accomplish:
    • PRODUCT DETECT C sensor gets triggered
    • (Wait 2.1 seconds)
    • GLUE SOLENOID L and GLUE SOLENOID R on for .55 seconds
    • (Wait 2 seconds)
    • GLUE SOLENOID L and GLUE SOLENOID R on for .55 seconds
    • (Wait 6.1 seconds)
    • TRAY FLAP ASSIST for 3.1 seconds
    • (then the next one, and over and over)
    That's a total of 14.4 seconds of operation, but the trays come every 7.5 seconds.

    What I don't fully understand is, if another case comes along and triggers that sensor, how does the first operation know to continue going?

    How do i program logic to accomplish this waiting, OUT coil, wait, OUT, etc...? (I don't know the wait part)

  • #2
    One way to accomplish this is to use the Shift / Rotate Bits instruction. (SFR)
    If time is what you want to use then let every bit represent 0.1 seconds. This 0.1-second timer would shift the bits.
    Product Detect C sensor will turn on a bit in this SFR instruction.
    The 21st bit past this will activate a timer for 0.55 seconds.
    The 41st bit past will activate another timer for 0.55 seconds.
    The 102nd bit past will activate the 'tray flap assist' for a time of 3.1 seconds.

    You can have multiple cartons in the machine using this type of program.

    Instead of time, I have seen gears driving this shifting of bits.

    I hope this helps you out.
    Regards,
    Garry
    _________________________________________________
    Garry
    ACC Automation
    https://www.accautomation.ca
    Connect with us on Facebook: facebook.com/accautomation/

    Comment


    • #3
      I guess supplying a bit of shrink for the help is out of the question.
      J/k wouldn't wish trouble on you.

      Comment


      • #4
        Originally posted by Garry View Post
        One way to accomplish this is to use the Shift / Rotate Bits instruction. (SFR)
        If time is what you want to use then let every bit represent 0.1 seconds. This 0.1-second timer would shift the bits.
        Product Detect C sensor will turn on a bit in this SFR instruction.
        The 21st bit past this will activate a timer for 0.55 seconds.
        The 41st bit past will activate another timer for 0.55 seconds.
        The 102nd bit past will activate the 'tray flap assist' for a time of 3.1 seconds.

        You can have multiple cartons in the machine using this type of program.

        Instead of time, I have seen gears driving this shifting of bits.

        I hope this helps you out.
        Regards,
        Garry
        Could you explain how I'd set this up? I'm still relatively new to ProductivitySuite.

        Originally posted by kewakl View Post
        I guess supplying a bit of shrink for the help is out of the question.
        J/k wouldn't wish trouble on you.
        If you're ever in MA, I can make sure you get some shrinkage...

        Comment


        • #5
          P1000 supports Drum Sequencers (DRM instruction). That might do the equivalent of the Shift Bits instruction, but without abstracting time to bits.

          Comment


          • #6
            "What I don't fully understand is, if another case comes along and triggers that sensor, how does the first operation know to continue going?"

            It would seem you'd need two operations on the controller (could be; tasks, stages, programs, functions, etc. depending on terminology used on your platform)

            e.g.
            IF product_sensor AND NOT operation1_busy start operation1
            IF product_sensor AND operation1_busy start operation2
            (IF product_sensor AND operation1_busy AND operation2_busy then the timing is messed up)

            if one had a significantly larger number of item on the line at one time one might consider a shift register (or equivalent) but for only two that might not be necessary, though possibly still an option.
            One thought, while you say "We're only running it at one speed" which would allow timers to be used e.g. "(Wait 2.1 seconds)" I'd consider using counters and count pulses from a sensor on some part of the machine, say a drive sprocket, if that gives sufficient resolution. That way if speed does change and the time it takes a box to travel from the product_sensor to the glue dispensers changes it won't be a problem since you'd be tracking distance not time, just an idea...
            Note that a shift register could also be clocked by a pulses from a sensor on the machine, which must be what Garry meant by "Instead of time, I have seen gears driving this shifting of bits.", though if one is old enough one has probably seen gears driving cams that operated switches (a series of cams could be arranged in a stack that might look something like a "drum" thus: "P1000 supports Drum Sequencers (DRM instruction)")
            Last edited by Tinker; 01-31-2020, 07:06 PM. Reason: speelling, addition

            Comment


            • #7
              Here's a quick and dirty example of the way I'd do it.
              Attached Files
              thePLCguy

              Bernie

              Comment


              • #8
                PLC PROGRAMMING EXAMPLE – SORTING STATION (SHIFT REGISTER)
                https://accautomation.ca/plc-program...hift-register/

                PLC Programming Example - Sorting Station Testing (Shift Register) - Video
                https://youtu.be/W0aibYb3DnE
                PLC Programming Example - Sorting Station (Shift Register) - Video
                https://youtu.be/YMl2DPm_yaU

                The above links will show you the shift register. In the example, a Do-More is used but this can be applied to the Productivity PLC as well, using the SFR instruction.
                The top link is the detailed information on the website. Videos have been made with Factory IO for demonstration in 3D.
                Click image for larger version

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                I hope this helps you out.
                Regards,
                Garry
                _________________________________________________
                Garry
                ACC Automation
                https://www.accautomation.ca
                Connect with us on Facebook: facebook.com/accautomation/

                Comment


                • #9
                  Originally posted by bcarlton View Post
                  Here's a quick and dirty example of the way I'd do it.
                  That's great, thank you. I was on the track of simple timers but couldn't get it working right. Will this work with an operation already underway (product sensor gets triggered again halfway through this)?

                  Comment


                  • #10
                    Originally posted by Orion HE View Post
                    P1000 supports Drum Sequencers (DRM instruction). That might do the equivalent of the Shift Bits instruction, but without abstracting time to bits.
                    Can you show me a code example of this?

                    Comment


                    • #11
                      Originally posted by craigmurphy View Post

                      That's great, thank you. I was on the track of simple timers but couldn't get it working right. Will this work with an operation already underway (product sensor gets triggered again halfway through this)?
                      Yes it will.
                      thePLCguy

                      Bernie

                      Comment


                      • #12
                        Originally posted by craigmurphy View Post
                        I'm recomissioning a machine that folds boxes around 24 cans of beer (4x6-pack or 6x4-pack or 24 loose, or 2x12-packs). The machine was purchased at auction and the HMI was shot, one of the two PLCs was shot (B&R) and the second (AB SLC 500) had a dead battery and no EEPROM - so no program. /backstory

                        I've installed a P1K and connected all the necessary sensors and some outputs. The machine is mostly mechanical - turn on the main motor, and the drive chains do 90% of the work. I need some logic to tell it when to shoot glue onto the flaps, that then get folded mechanically.

                        I'm looking for some help on how to accomplish this. We're only running it at one speed - 15% faster than the canning line runs at, or a case every 7.5 seconds. Based on that, I've measured the distance between the sensor and the glue nozzles, and then a pneumatic arm that presses the flap onto the hot glue. I did some basic math to then tell how long it needs to wait until it shoots glue, how long to shoot glue, how long to wait until the second flap, how long to shoot glue again, another wait, and then pressing the flap assist. The breakdown is below...

                        Here's what I need to accomplish:
                        • PRODUCT DETECT C sensor gets triggered
                        • (Wait 2.1 seconds)
                        • GLUE SOLENOID L and GLUE SOLENOID R on for .55 seconds
                        • (Wait 2 seconds)
                        • GLUE SOLENOID L and GLUE SOLENOID R on for .55 seconds
                        • (Wait 6.1 seconds)
                        • TRAY FLAP ASSIST for 3.1 seconds
                        • (then the next one, and over and over)
                        That's a total of 14.4 seconds of operation, but the trays come every 7.5 seconds.

                        What I don't fully understand is, if another case comes along and triggers that sensor, how does the first operation know to continue going?

                        How do i program logic to accomplish this waiting, OUT coil, wait, OUT, etc...? (I don't know the wait part)
                        I'm late to the party, but have been building case/tray packers for over 40-years. Despite your machine being mechanical, these machines are built to work "on-demand." So definitely, the glue application should be coded to repeat. It's also a good idea to have the settings as part of a recipe so you can do the same logic for multiple size trays and have the settings stored in an array.

                        The timing example you give for glue application sounds strange; who's the manufacturer of the machine? Is there a YouTube video from the manufacturer of your model machine in operation? Anyway, if you could post some photos of the machine, I could assist you.

                        Good luck!
                        Why worry? If you've done the best you can, worrying won't make it any better

                        - Walt Disney

                        Comment


                        • #13
                          Originally posted by Todd Dice View Post

                          I'm late to the party, but have been building case/tray packers for over 40-years. Despite your machine being mechanical, these machines are built to work "on-demand." So definitely, the glue application should be coded to repeat. It's also a good idea to have the settings as part of a recipe so you can do the same logic for multiple size trays and have the settings stored in an array.

                          The timing example you give for glue application sounds strange; who's the manufacturer of the machine? Is there a YouTube video from the manufacturer of your model machine in operation? Anyway, if you could post some photos of the machine, I could assist you.

                          Good luck!
                          It's a Krones Variopac TFS60, and we've stripped it to only doing tray forming (no shrink wrap). We're also adding our own laning system to be controlled via PLC, and forward and aft conveyors, also controlled by this PLC.

                          The machine is only running at 1 case every 7.5 seconds, which is why it probably seems strange. This machine can run like 5 times faster.

                          Comment


                          • #14
                            Originally posted by craigmurphy View Post

                            It's a Krones Variopac TFS60, and we've stripped it to only doing tray forming (no shrink wrap). We're also adding our own laning system to be controlled via PLC, and forward and aft conveyors, also controlled by this PLC.

                            The machine is only running at 1 case every 7.5 seconds, which is why it probably seems strange. This machine can run like 5 times faster.
                            Krones are typically meant to run continuous motion, so I'm assuming you're just running it at a much slower motor speed to accommodate your throughput? Anyhow, on machines as this, there's typically an encoder to provide a pulse train to match machine speed, and it is what you should use to create your glue application timing.

                            Again, good luck!
                            Why worry? If you've done the best you can, worrying won't make it any better

                            - Walt Disney

                            Comment


                            • #15
                              Originally posted by craigmurphy View Post

                              Can you show me a code example of this?
                              Click image for larger version

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                              The sequencers are identical, but interlocked so they can both run simultaneously, but must complete before running again.

                              Step 1 is to detect the carton.
                              Step 2 is wait 2100ms (2.1 seconds).
                              Step 3 is 550ms long but energizes the glue solenoids for the duration, deenergizing them when the step is finished.
                              so on and so forth.

                              I may have missed something, but it seems like a viable option. One aspect of programming that I enjoy is the variety of ways we can accomplish the same task. I don't necessarily prefer drum sequencers, but I've used them to get the work done in a few scenarios.


                              Comment

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