| 摘要 |
1,102,257. Digital data communication system. WESTERN ELECTRIC CO. Inc. 28 July, 1965 [23 July, 1964; 28 July, 1964], No. 32159/65. Heading G4A. [Also in Division H4] A modification of the communications unit of Specification 1,102,258 incorporates a filter device acting to pass information proceeding to preselected receiving stations but to prevent data from reaching the other receiving stations. The filter comprises a set of gates acting as modulo 2 adders which receive appropriate bits of the six-bit multiplexed word according to the matrix PI*P<SP>-1</SP> where I* is a modified unit matrix having zero's in its diagonal corresponding to stations which are not to receive information and ones in its diagonal corresponding to stations that are to receive information. The filter is then followed by a decoder as described in 32160/65. As shown (Fig. 1b) the filter 80 passes information for stations 70 1 , 70 2 , 70 3 , but not for stations 70 4 , 70 5 , 70 6 . |
