SCSI signals are negative true logic, meaning that the signals are normally asserted for a "0". In the past, to change a "0" to a "1", the signal drive was simply removed and the signal allowed to "drift" to the unasserted state. For Ultra data throughput this method is barely fast enough but it is not fast enough for LVD or faster data throughputs. To overcome this, "active negation" is used to drive the signal to the unasserted state. This allows more rapid transitions for LVD and faster SCSI data throughput. The SCSI specifications recommend active negation for Ultra SCSI devices and specify it for LVD and faster.

This definition is in context to SCSI. See more contextual defintions for Active Negation.