# LOGIC/BOOLEAN FUNCTIONS

There are 4 logic functions available: BOOL 1, 2, 3, and 4. There are 6 operations to choose from:

**NOT**: the NOT function returns the inverse value of factor A, the factor B does not be configured as NOT has only one binary variable. Therefore, if the factor A is zero, the result will be 1 and vice versa.

**AND**: the AND function returns a value of 1 if all the factors have a value of 1, while it returns 0 in all other cases: when the factor A is 1 and the factor B is zero o vice versa or if both factors are zero. This operation is equivalent to having two contacts in series: they both must be closed for the signal to pass.

**OR**: the OR logic function return 1 if at least one of the factors is 1, while it returns 0 in every other cases. This operation is equivalent to having two contacts in parallel: one of the two must be closed for the signal to pass.

**XOR**: the XOR function, also known as EX-OR,*exclusive OR,*or*sum module 2*, returns 1 if and only if the number of factors equal to 1 is odd, while it returns 0 in all other cases.

**FLIP FLOP S/R:**flip/flop are*sequential*digital circuits whose task is to save a bit. A digital circuit is said*sequential*if the output (Result) depends on the applied inputs (Factors) and on the previous status of the same output. A sequential circuit, therefore, must remember its*previous status*. The Flip-flop S/R (Set-Reset or Start-Stop) is the simplest memory device and has two inputs called Set (Factor A) and Reset (Factor B) and one output referred to as Result. Therefore, if the Factor A is equal to 1 even for 1 second, the result is 1 as long as Factor B being equal to 1 (even just for a second) resets the value of the result back to zero.**FFAP:**is always a flip-flop that accepts two factors, the first Factor A is the Start signal, therefore if it is equal to 1 the result is equal to 1, while the result is equal to zero only if both factors (Start factor A and Stop factor B) are equal to zero.

All 6 operations can return a value of 0 or 1 and can be used anywhere in RegConfig when digital inputs are provided, e.g., as block signal of a source by selecting VDoutH from the drop-down menu and then the logic function programmed in Free Signals:

Boolean functions can also be used to manage digital outputs: