公开(公告)号：FR2721782B1

公开(公告)日：1997-10-03

申请号：FR9506155

申请日：1995-05-19

Applicant: IBM

Inventor： BOGGS ANDREW KENNETH ,  HOANG QUY N ,  JACOBS JOE ,  MULLEN JOHN MARK ,  PURRINGTON CHALLIS ,  WEAVER LAURA A

IPC: H04L12/433 ,  H04L29/00 ,  H04L29/08 ,  H04L29/06 ,  H04L12/24

Abstract: An intelligent multistation access unit is provided having a transmission speed detection circuit for determining the data transmission speed of an attached device attempting to gain access to a node of a multiple transmission rate digital data communications network. The intelligent multistation access unit is comprised of a speed detect circuit, which indicates the data transmission speed of the attached device, a switching circuit which directs the attached device to the speed detect circuit until switched to allow the attached device access to the network node, and a processor that controls the switching circuit and which permits the attached device access to the node depending on the data transmission speed indication.

公开(公告)号：FR2721782A1

公开(公告)日：1995-12-29

申请号：FR9506155

申请日：1995-05-19

Applicant: IBM

Inventor： BOGGS ANDREW KENNETH ,  QUY N HOANG ,  JACOBS JOE ,  MULLEN JOHN MARK ,  PURRINGTON CHALLIS ,  WEAVER LAURA A

IPC: H04L12/433 ,  H04L29/00 ,  H04L29/08 ,  H04L29/06 ,  H04L12/24

Abstract: The unit includes a speed detection circuit (36) which indicates the transmission speed of data in a linked device (12). The speed detection circuit includes a timer which generates a synchronisation period and a transition counter which counts the transmission data transitions in the linked device for each period. An indicator signals when the number of transitions counted exceeds a threshold number during the timing period. A switching circuit is coupled to the speed detection circuit until it is switched for access to a device linked to a network node (16). A processor (32) controls the switching circuit and allows the device linked to reach the node indicated by the data transmission speed which corresponds to the network speed.