公开(公告)号：US4667323A

公开(公告)日：1987-05-19

申请号：US771834

申请日：1985-09-03

申请人： Jonathan R. Engdahl ,  Jeffery A. Hanneman ,  David C. Sweeton

发明人： Jonathan R. Engdahl ,  Jeffery A. Hanneman ,  David C. Sweeton

IPC分类号： H04L12/417 ,  H04J3/02

CPC分类号： H04L12/417

摘要： A communications network is comprised of two or more stations which share mastership of the network by passing a token between them. While a station holds the token it may send low or high priority messages. It may also inform other stations of its intent to exit the network and it may solicit for new stations wanting to enter the network. The token is passed from station-to-station in accordance with a predetermined time schedule which insures each station fair access to the network while insuring that messages are conveyed between stations within a predetermined worst case time delay.

公开(公告)号：US4780869A

公开(公告)日：1988-10-25

申请号：US52707

申请日：1987-05-20

申请人： Jonathan Engdahl ,  Lawrence Esker ,  Thomas J. Bray ,  Jeffery A. Hanneman

发明人： Jonathan Engdahl ,  Lawrence Esker ,  Thomas J. Bray ,  Jeffery A. Hanneman

IPC分类号： H04L1/02 ,  H04L12/413 ,  H04J1/16 ,  H04J3/14

CPC分类号： H04L12/40182 ,  H04L1/02 ,  H04L12/413 ,  H04L2012/4026

摘要： A redundant local area network uses two cables over which duplicate information is transmitted in parallel in the form of identical message frames. Each receiver on the network includes a circuit which evaluates the signals from the two cables and selects one of the signals to be processed. This circuit determines the length of the message frames received on each cable for a given transmission and indicates which cable, if any, carried the longer frame. The signal from the cable that carried the longer frame is then selected as the output of the receiver. Additional circuitry is provided to prevent two short frames on one cable from being considered as one long frame. An apparatus is provided to look at the historical reliability of the signals on the cables so that if one cable has had a significantly better performance than the other, a single poor transmission on the one cable will not cause the historically poorer cable to be selected until such time as the poorer cable has redeemed itself.

摘要翻译： 冗余局域网使用两条电缆，复用信息以相同消息帧的形式并行发送。 网络上的每个接收机包括评估来自两根电缆的信号并选择要处理的信号之一的电路。 该电路确定在给定传输中每条电缆上接收的消息帧的长度，并指示哪个电缆（如果有的话）携带较长的帧。 然后选择承载较长帧的电缆的信号作为接收机的输出。 提供附加电路以防止一根电缆上的两个短帧被认为是一个长帧。 提供了一种设备来查看电缆上的信号的历史可靠性，使得如果一条电缆具有比另一条电缆明显更好的性能，则一根电缆上的单个不良传输将不会导致历史上较差的电缆被选择直到 这个时间比较穷的电缆已经赎回了。