This block is a non linear function modulo where the input and output are
real values.
According to the parameters 'Amplitude', the output can't overflow the minimun and
the maximun value of 'Amplitude'.
This block computes
where 'm' is the value of 'Amplitude', 'u' the input and 'y' the output.
This function is similar to the scilab 'modulo' function.
The value of the output is positive or zero.