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How to reset the Alarms triggered after timer has expires

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  • How to reset the Alarms triggered after timer has expires

    Hi Everyone - I need your input - I created an LD program for a 5 Alarm system - The system is divided into 2 parts - 1st part the absent of signal (24v) (input X4) triggers a general Alarm (Y5) and start a timer - 2nd part - After Timer has been completed - I am resetting 3 relays - R11 - to remove the input signal (X4) and this way - allow my equipment to trigger the alarm that originated the problem (Y4). R2 - To reset my general alarm output (Y5) and Y5 - To reset the general output. . What this does it allows my Equip to finish processing by enabling (Y5) and then trigger the true alarm (Y4) - by removing the signal..

    However - What I noticed is that when the timer has elapsed. R11 is energized and removes the signal from Y4 - which is what I want! - My question is in order to reset the timer or restart the program once my Equipment has been fix - Is resetting the PLC - RUN-PRG-RUN is correct (Good Practice) or is it something by code that I can include?

    The Picture shows one alarm - the are 5 of this - basically the same setup w/ different timers - The LD logic is from another PLC (Panasonic -PLC), however I want to do the same on the Click?Click image for larger version

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    Thanks in advanced for your feedback

  • #2
    This logic should not be hard to accomplish on the Click.
    To reset the timer on the Click, the contact that enables the timer can be opened to reset the timer.


    • #3
      Changing plc state from run to stop is not good practice. You should be able to reset the outputs without resetting the plc.
      the rung 3 you donít need to set the y5 because is latched as long as x4 is off.
      the rung 4 is weird. You canít have outputs in series. A plc program resembles an automation cabinet. You wonít see relays energized in series, but only in parallel.
      you accidentally made a program that kind of works.
      the issue that you have is related to the use of set and reset instructions. Those can only clear at plc reset. Try to use coil instructions ( normal output).
      Last edited by Alexandru; 04-17-2019, 10:07 AM.


      • #4
        Thanks Roger and Alexandru! - Alex - going by your feedback - You are correct - no need to trigger the coil in series - No sure why I did it this way - Rookie mistake!! So on Rung 3 - Just change my Y5 to a regular coil - Then in reality in Rung 4 I only need to energized R11 in order to trigger Y4(This output will stop the signal to pass through and therefore - Aborting my Equipment!! Thanks for the feedback!! I will try this changes and see if it works