Computer Hardware Terms, Glossary and Dictionary
A vampire tap (also called a piercing tap) is a device for physically connecting a station (i.e. a PC, a printer, or another device) to a network that uses 10BASE-5 cabling. This device clamps onto the cable, forcing a spike through a hole drilled through the outer shielding to contact the inner conductor while other spikes bite into the outer conductor. Vampire taps allow new connections to be made on a given physical cable while the cable is in use. This allows administrators to expand bus-topology network sections without interrupting communications.
Also called a piercing tap.