PROCEDE POUR CONSTATER DES DEFAUTS DANS DES POSTES INTERMEDIAIRES, POURVUS DE REGENERATEURS, D'UN RESEAU DE TRANSMISSIONFONCTIONNANT EN MODULATION PAR IMPULSIONS

摘要

1335743 Pulse signalling SIEMENS AG 19 April 1971 [12 Feb 1970] 21384/71 Addition to 1212908 Heading H4L In a PCM system having a testing arrangement for intermediate stations as described in Specification 1,212,908, the test signal is modulated by a higher-frequency signal and demodulated at the intermediate station before being applied to a band-pass filter of distinctive frequency.