adccommunitymod (AutomationDirect) asked a question.

Count down timer on Click PLC

Created Date: January 28,2016

Created By: NATEM

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I have a liquid filling machine application for which I am using a Click PLC and a Cmore EA9 HMI. The fill heads use a count down timer to give us our desired fill weight. The problem I have is the maximum time I can put in the DS data register for timers is 32767 ms because it is a 16 bit register. If I want to go higher than that, I have to set the units to seconds. That is not good because we need finer time adjustments than whole seconds. I am wondering if there is any kind of work around to get more than 32.767 seconds on the timer.


  • adccommunitymod (AutomationDirect)

    Created Date: January 28,2016

    Created by: kewakl

    You could cascade a timer an a counter.

    Have a timer time for (?) 10 mS and expire. Then have a counter count the expirations of the timer. Reset the timer and go again.

    Or the expiration could trigger a math box to count the expirations in a DD location.

    Then your code could do whatever you need to relate the counting of 10 mS intervals to the timing you require.

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  • adccommunitymod (AutomationDirect)

    Created Date: January 28,2016

    Created by: NATEM

    Thank you for the reply kewakl.

    It should be a fun challenge to work that one out. I don't have a lot of experience programming. It will be cool if I can pull it off though.

  • adccommunitymod (AutomationDirect)

    Created Date: January 28,2016

    Created by: kewakl

    If 1/2 second resolution is good enough, make the timer 500mS.

  • adccommunitymod (AutomationDirect)

    Created Date: January 29,2016

    Created by: Tinker

    Once one is using a counter (which use long integers so range won't be much of a problem, one could count more than three weeks at 1ms) there are system bits for various time intervals, SC5 is 100ms, might be a good option. There is also SC4 at 10ms, but as that is 5ms on and 5ms off I'd be a bit worried about scan time.

    I hesitate to mention this since you said; "It should be a fun challenge to work that one out. I don't have a lot of experience programming "

    But, the CLICK does have timed interrupts, one could increment a DD register, in a 10ms interrupt without any problem. I once did that at 1ms for a tachometer application, while it did seem to work, I think 1ms might be pushing ones luck a bit, and that was only incrementing a register in the interrupt program, to actually do anything at a millisecond resolution ones handler might be too long for that rate (in my tachometer I used a hardware interrupt triggered by a prox. sensor to make a copy of the time, which I then processed in the regular "main " program.)

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  • adccommunitymod (AutomationDirect)

    Created Date: February 19,2016

    Created by: NATEM

    100 ms timer

    Tinker

    The 100 ms clock pulse works.

    Now I just have to build it into the rest of my program.

    Thanks

  • adccommunitymod (AutomationDirect)

    Created Date: January 28,2016

    Created by: NATEM

    I have a liquid filling machine application for which I am using a Click PLC and a Cmore EA9 HMI.

    The fill heads use a count down timer to give us our desired fill weight.

    The problem I have is the maximum time I can put in the DS data register for timers is 32767 ms because it is a 16 bit register. If I want to go higher than that, I have to set the units to seconds. That is not good because we need finer time adjustments than whole seconds.

    I am wondering if there is any kind of work around to get more than 32.767 seconds on the timer.

    Expand Post