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R_Trig and F_trig use in FB , Tag decleration

qwazee

Hello.

Which PLC and program language are you using?
You could use these:

The SCL language can use something like:

#pPulse   := #input and not #oldstate; // rise
#nPulse   := not #input and #oldstate; // fall
#change   := #input <> #oldstate; // state change
#oldstate := #input; // copied state

 

 So simple.
From the times of S5.
Siemens is cool.