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What is this mystery function?

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I want to put one of these into a program I am writing but for the life of me I cannot remember what it is called (or where it is located in the panel).

I drew it from memory in MS Paint and how it is wired, though I cannot remember if it sends a boolean true/false or if it sends the value.

It stores a value in memory from the control it is wired to.  If the value doesn't change, it doesn't do anything (or sends a false constant).  If the value does change, it sends the new value (or a true constant).

 

On second thought I am pretty sure it sends boolean values, though I don't see it in the boolean tab.

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Solution
Accepted by LarsUlrich

If you're refering to the "arrow" it could be a feedback node..functions>programming>structures

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haha I think that is it

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So my memory wasn't quite right as to what it looked like, but that was it!  Thank you!

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Yeah, and it does not output a Boolean either...

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@LarsUlrich wrote:

If the value doesn't change, it doesn't do anything (or sends a false constant).  If the value does change, it sends the new value (or a true constant).


A feedback node does not do that alone. You need additional code, for example a "not equal". (there is also an openg tool)

 

Here's simple demo. (The LED will light up for one iteration whenever the numeric changes its value.)

 

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