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Old May 16th, 2008, 06:35 PM   #1
sas11
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debounce

Hello Again,
Simple question for you guys. I am having trouble with a n.c. air pressure switch. I believe I need to have some debounce? in my program. But i do not know how to write it. Could someone provide me with a rung example? If it matters i am using Direct Logic from automation direct.

Thanks
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Old May 16th, 2008, 06:44 PM   #2
geniusintraining
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Try this... you will need to convert it to AD but should not be that hard

http://www.plctalk.net/qanda/showthread.php?t=32911
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Old May 16th, 2008, 06:46 PM   #3
bkottaras
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You will need to setup a "debounce' timer.
Your sensor starts the timer and the timer is done timing after a preset
amount of time which you need to determine (100mSecs will do just fine for starters).
Once the timer is done timing do the logic that you intented to do when the sensor was made.
Setting up a debounce timer avoids rapid/false triggering.
Hope this helps.
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Old May 16th, 2008, 07:19 PM   #4
sas11
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Thanks,
Does the debounce only have to be used when my switch is closing?
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Old May 16th, 2008, 08:13 PM   #5
Lancie1
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Sas,

If your switch is Normally Closed, and opens at some pressure, then when it opens, start a timer, wait for switch to settle out, then use the "Timer Finished" bit to perform the next step of your control (whatever it may be). This will prevent a situation where the switch opens, closes, then opens again, causing erratic operation of your machinery.
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Old May 16th, 2008, 09:06 PM   #6
sas11
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Thanks everyone. This will help
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