公开(公告)号：US3571806A

公开(公告)日：1971-03-23

申请号：US3571806D

申请日：1969-01-14

Applicant: IBM

Inventor： MAKIE DAVID ,  MALLAR EUGENE E JR ,  STEEN ROBERT F

IPC: H04L13/06 ,  G06F13/00 ,  G06F13/38 ,  H04L7/00 ,  H04L25/50

CPC classification number: G06F13/385

Abstract: A line adapter for data transmission systems is provided with a pair of oscillators for enabling reception of signals at two different rates. An initial synchronizing character is analyzed to determine the number of voltage transitions during the period needed for transmission of the character at the higher transmission rate. If the number of transitions counted does not correspond with the number of voltage transitions in the character, a shift is made to a lower speed oscillator for data reception at the slower rate.

公开(公告)号：US3569943A

公开(公告)日：1971-03-09

申请号：US3569943D

申请日：1969-04-02

Applicant: IBM

Inventor： MACKIE DAVID ,  MALLAR EUGENE E JR ,  STEEN ROBERT F

IPC: H04L25/38 ,  G06F13/00 ,  G06F13/38 ,  H04L13/06 ,  H04L29/08 ,  G05B11/00 ,  G06C9/00

CPC classification number: G06F13/385 ,  G06Q20/203

Abstract: A variable speed line adapter for receiving start-stop data transmission is normally set for reception at one speed and will examine the starting characters of received data at that speed. If the first received character is not a complete and valid starting character for the initial receiver speed, a shift is made to another receiver speed and the next data character examined. By a proper selection of starting characters, the adapter may be switched from one speed range to another until the line adapter is set to receive at the speed of the transmitted signal.