Debouncer

ABB_User

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A
Hi

Is the Input delay = 7 ms on my plc good enough ?

It is for relays and input switch.

That are you using ? an extra timer on ie 150ms ?

Thanks.
 
Hi

Is my question to easy ??

Or did I not explained my problen good enough ??

I am sory if there is som spelling errors.
 
ABB_User said:
Is my question to easy ??
Click to expand...

Probably Yes!

ABB_User said:
Or did I not explained my problen good enough ??
Click to expand...

Not really.

ABB_User said:
I am sory if there is som spelling errors.
Click to expand...

Spelling mistakes are not a problem.


Can I suggest that you click the search button and search this site for the keyword debounce and I am sure you will find the answer that you are looking for, if not give us a bit (lot) more information about what you are trying to achieve and with what, then maybe we can answer your question specific to your needs.

Paul
 
I don't know specifically about your input module but I have found that the standard debounce (for example 8ms on AB MicroLogix DC input) has been sufficient for standard contact bounce from limit switches and relays. You should only have to worry if the actual actuation of the sensing device tends to be mechanically bouncy.
 
If you want to be sure, use oscilloscope to check signal edges.
I my experience default setting of 5-10mS on mose PLCs was
sufficient in 99% of cases. Only occasionally like when
dealing with moving parts (bottles or whatever...) which
can "bounce" on the conveyor, I would add additional
debouncing. Standard inputs such as relays, push buttons,
sensores etc. seam to work fine.
Do you need extra debounce? It's up to you. How much
damage would one "glitch" cause or cost? How much
signal delay you can aford? You decide...
That's engineering decision.
 
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