DIFU and OSR

Hello, I have been trying to put together a short training manual for very basic PLC understanding for my Technicians. I have had some training myself but the DIFU information I have seems confusing to me now. I just went to the http://www.plcs.net/chapters/oneshot18.htm and it gives a nice explanation of a flip flop circuit and how it works but what I am looking for is what are the other ways it can be used in programs. I remember something about "switch bounce" but the notes I took are not jogging my mind as to the application. Any other unique or specific applications of the OSR would be greatly appreciated.

Thanks

Switch bounce is to do with what happens when a contact closes, could you possibly mean switch debounce? Which is something more relevant to this forum?

Rob

Thanks Rob, that is very likely, like I said my notes are confusing to me and at this point I am tossing them on this subject (I am not the best note taker). I am really looking for some of the many applications a DIFU can be used for in the PLC programming world. Can you explain debouncing to me?

In Omrom PLCs I often use @++ DM200 for example. This increments a channel count by one on the rising edge of the input. No need to use a DIFU as @ in a function does the same thing and effectively is the same.
Also use DIFU to latch a sequence and the like.

A debounce timer for instance would be used say when you have an input that might flicker on and off but you are looking for the input been high for say 2 seconds before it is acknowledged in your program, imagine for example a water tank level switch and as it is filling the tank you can get the odd water splash hit the switch and shuts the valve then the switch isn't made and reopened the valve, and this just goes round in
Circles so you set the debounce to ignore any blips that it may see.

Also the same thing on a conveyor system, a box erector is feeding a machine that fills the boxes so you want to ignore the sensor input if it comes on for say 5 seconds because this is just a box passing the sensor but anything more than 5 seconds it stops the machine building boxes because the conveyor is now full of ready made boxes as soon as the sensor is no longer made then the box erector can start up again, this is known as build back

Thanks Rob and Bob, I never really understood why one is used in front of a counter, I seem to see this a lot.