The constant beeps that you are hearing from the Parent Unit only is the TIC function. This indicates that your monitor is detecting movement without physically looking at the Parent Unit screen.
Some parents love this sound as they find it reassuring, however not all do so this is an optional function so you can monitor baby's movements without this.
To set your monitor to detect movement without the TIC beeps, when looking at the back of the Nursery Unit move the wing on the left hand side to the middle position – TIC OFF.
Your monitor will now continue to detect your baby’s movement without the constant beeps.