Circuit arrangement for the construction of the inside compounds in a centrally controlled remote alarm switching -, in particular a telephone exchange system

摘要

1,161,705. Automatic exchange systems. NIPPON TELEGRAPH & TELEPHONE PUBLIC CORP., OKI ELECTRIC INDUSTRY CO. Ltd., NIPPON ELECTRIC CO. Ltd., HITACHI Ltd., and FUJITSU Ltd. 30 March, 1967 [14 April, 1966], No. 14476/67. Heading H4K. In a cross-bar exchange in which the calledparty-to-junctor side of a connection is established before the calling party-to-(the same) junctor side of the connection is established, if equipment busy is encountered during the setting up of the calling side connection, the original called side connection is released and a new junctor and called side path to this junctor are selected whereafter a further attempt at completing the calling party-to-(new) junctor connection is made. This allows either the blocking factor to be decreased or the number of junctors to be decreased without an increase in blocking. The sequence of events can be followed from Fig. 2 where IOT represent junctions and LLF, TLF the usual line-link and trunk-link frames of the switching network. A common marker M, when apprised of the calling and called number by a register REG (if necessary with the help of a directory/equipment number translator NG), selects a path I between the called subscriber SubSP1/SP and a free junctor IOT, 8. Thereafter M attempts to complete a path II between the caller Sub and the same junctor IOT, 8. If equipment busy is encountered, path I is dropped and paths III and IV in that order are set up. A method of breaking down the called side connection by removing battery from the C-wire is described with reference to Fig. 3 (not shown) and a relay chain circuit which controls the break down of the original connection and the setting up of the new connections is described with reference to Fig. 4 (not shown).