公开(公告)号：US4211895A

公开(公告)日：1980-07-08

申请号：US857744

申请日：1977-12-05

申请人： John C. H. Davis ,  Krishnaswamy Natarajan ,  Jan Cihal ,  Motek Szpindel ,  Jeffrey Sidwell

发明人： John C. H. Davis ,  Krishnaswamy Natarajan ,  Jan Cihal ,  Motek Szpindel ,  Jeffrey Sidwell

IPC分类号： H04Q3/52 ,  H04Q1/30 ,  H04Q3/56

CPC分类号： H04Q3/521

摘要： An electronic telephone system has a plurality of extensions connected radially to a central equipment by respective cables each providing separate speech and signalling paths. Each of the signalling paths is provided by a balanced conductor pair terminated by a matching impedance at the extension unit. The conductor pairs are connected to a common control unit at the central equipment, which scans the extensions in a time-division multiplex mode, signalling data being transmitted over the conductor pair from the addressed extension to the control unit in a first period of the time slot allotted to the extension, and signalling data being transmitted from the control unit to the addressed extension in a second period of the allotted time slot. The system is also served by a number of trunks, which are scanned by the common control unit, the trunks being interfaced with the central equipment by interface units which include protective circuitry and logic control circuits.

摘要翻译： 电子电话系统具有多个通过相应电缆径向连接到中央设备的延伸部，每个电缆提供单独的语音和信令路径。 每个信令路径由在扩展单元处由匹配阻抗终止的平衡导线对提供。 导体对连接到中央设备的公共控制单元，其以时分多路复用模式扫描扩展，在第一时间段内通过导体对将信令数据从寻址的分机发送到控制单元 分配给扩展的时隙，以及在所分配的时隙的第二周期中从控制单元发送到寻址的分机的信令数据。 该系统还由多个中继线服务，这些中继线由公共控制单元扫描，中继线通过包括保护电路和逻辑控制电路的接口单元与中央设备接口。