The new WJ-ND400 by Panasonic is ideal for large scale surveillance systems with 9 serial ATA HDD slots with each optional extension unit also containing 9 serial ATA HDD slots for additional capacity. Up to 64 network cameras can be connected to the WJ-ND400 and their high quality images and audio data recorded simultaneously. The WJ-ND400 comes with hot plug support which enables drives to be replaced without any downtime, allowing for continuous 24/7 operation. In addition, the WJ-ND400 allows the operator to search recordings with its intelligent VMD function. The VMD function allows movement in a specified area in the recorded images to be quickly searched.