发明名称 System for selectively coupling a plurality of stations into a single communications path
摘要 A system is disclosed for selectively serially coupling a plurality of stations in a communications network into a single communications path. In the system of the invention, a plurality of tap boxes are serially coupled into the single communications path. Each station is coupled to a desired associated one of the tap boxes by way of an associated tap cable. When the tap cable is connected to a first portion of the tap box, a first impedance corresponding to the characteristic impedance of the single communications path is serially coupled into the single communications path to enable the station associated with the tap cable to be coupled to the single communications path by way of the first impedance. When the tap cable is connected to a second portion of the tap box, the first impedance is effectively removed from the single communications path and a test impedance is coupled to the tap cable to enable the station associated with the tap cable to test itself. In a first embodiment, the first and second portions of the tap box are respectively the tip and ring contacts of a stereo jack. In a second embodiment, the first and second portions of the tap box are separate audio jacks. In each embodiment, a connection means, such as a monaural plug, is connected to the end of each tap cable and is used to selectively couple the tap cable to either of the first and second portions of a desired tap box.
申请公布号 US4682325(A) 申请公布日期 1987.07.21
申请号 US19840686579 申请日期 1984.12.27
申请人 NCR CORPORATION 发明人 HEYS, JR., GEORGE;ALESHIRE, REX A.;HINES, FRANK;BELKNAP, WILLIAM M.
分类号 H03H7/38;G06F13/40;H03H7/48;H04B3/02;H04L12/40;H04L25/02;H04M9/02;(IPC1-7):H04J3/02 主分类号 H03H7/38
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