Steuereinrichtung zum automatischen Fernsprech-Verbindungsaufbau mit Wegsuche

摘要

1,159,914. Automatic exchange systems. NIPPON TELEGRAM & TELEPHONE PUBLIC CORP., OKI ELECTRIC INDUSTRY CO. Ltd., NIPPON ELECTRIC CO. Ltd., FUJITSU Ltd., and HITACHI Ltd. 4 April, 1967 [14 April, 1966], No. 15437/67. Heading H4K. In a cross-bar exchange having a common translator for providing routing instructions to the markers, the translator includes an alltrunks-busy relay in respect of each route, the contacts of these relays being formed in a chain so as to automatically provide an enquiring marker with instructions regarding the first available route and the marker includes a set of relays which in the event that a path from the calling party to a trunk of the first choice route cannot be set up through the switching network causes the marker to attempt to set up a connection to the other idle trunks if any in this route and thereafter causes this route's all-trunks-busy relay to be operated whereby the translator can then provide the marker with instructions regarding the next available route. This process can be repeated as often as required before busy tone is reverted to the caller. The marker applies to the translator after each unsuccessful attempt to reach an idle trunk and the translator then supplies instructions regarding the same route if this contains any more idle trunks. The trunk which could not be reached on a previous attempt is artificially busied during succeeding attempts to reach an idle trunk of this route or of any other lower priority route. The artificial busying is only removed when the call is finally connected through to a trunk or is abandoned. The relay arrangements in the translator and marker are described with reference to Fig. 3 (not shown). The system is contrasted with the No. 5 Cross-bar System (U.S.A. 2,585,904), where all-trunks-busy conditions are determined in the marker, the present system being faster due to the translator considering the availability of a route before it issues routing instructions.