公开(公告)号：US3612781A

公开(公告)日：1971-10-12

申请号：US3612781D

申请日：1969-07-24

Applicant: IBM

Inventor： COSTA DONALD J DA ,  NOGUCHI ROBERT Y ,  WINTER LEONARD F

IPC: H04L5/14 ,  H04L12/40 ,  H04M1/58

CPC classification number: H04L5/1423 ,  H04L12/40

Abstract: This specification describes a circuit which permits the simultaneous transmission of data in two directions on a common transmission line without the use of frequency or time discrimination. The circuit includes at each location a differential amplifier with two inputs, one input receives data to be transmitted onto the line from the particular location and the other input receives both the data being transmitted onto the line from the location and the data being received on the line at the location. The two inputs are isolated from each other so that the output of the differential amplifier which goes to the location receiver is a function only of the data received on the line at the location.