Gives positions of changes of an array. Helps to retrieve which values have changed inside an array.
If several values have changed at the same time, changes are queued, and only one value is given by BLOC calculation.
If the queue length is greater than 8192 an error message is generated: queue overflow in Array Difference module
Index (position) of the last change.
Old value at the index position before it changes
New value at the index position.
Returns 1 if the array has changed, 0 otherwise. Changes are queued so it stays at 1 for several consecutive BLOC calculation.