The (time varying) Real output signal of this block can be defined in its
parameter menu via variable y. The purpose is to support the
easy definition of Real expressions in a block diagram. For example,
in the y-menu the definition "if time < 1 then 0 else 1" can be given in order
to define that the output signal is one, if time ≥ 1 and otherwise
it is zero. Note, that "time" is a built-in variable that is always
accessible and represents the "model time" and that
Variable y is both a variable and a connector.