Previous: dup killer Next: Duplex High Speed Data
<communications> Communications with one channel in each direction. If data can flow in both directions simultaneously the communications is "full-duplex" else it is "half-duplex".
A simplex channel can only carry one message at a time, though it does not imply the channel is unidirectional.
The term "duplex" was first used in wireless, telegraph, and telephone communications, where "duplex" circuits between communicating terminals were capable of transmission in both directions, and "simplex" indicated transmission from a sender to a receiver, or broadcast to several potential receivers.
Nearly all communications circuits used by computers are two-way, so the distinction between simplex and duplex is seldom made.
(2000-03-30)