I couldn't be sure how to make a proper headline, correct me if I am wrong with it.
I have a reasonably working push button solution including hardware de-bouncing. There is no question on that.
So, now, I was asked if i can also feed that MCU pin directly from a PLC. There is no secret with that. I choose an optocoupler (LTV-844). It has NPN open collector output.
My question is; should I expect any complication when I connect open collector output of the optocoupler and Schmidt Trigger output to the very same MCU pin? if so, what would be the solution?
A hint; that two outputs won't be available at the same time (mutually exclusive by design).