DIRECT CONNECTION DIGITAL TRANSMISSION APPARATUS

摘要

Apparatus is disclosed for interconnecting digital data stations through a transmission medium such as a directly connected unloaded pair of wires. The apparatus transmits data as polarity, or more correctly, direct current reversals on a pair of wires indicative of "ones" (1) and "zeros" (0) or marks and spaces. The apparatus includes means for discriminating against noise spikes which may appear on the line without degrading the quality of valid signals Control information is uniquely codes as spaces (0) of predetermined lengths which are distinct from any valid data.