GB1198469A - Circuit Arrangements for Controlling the Setting-up of Connections - Google Patents

Abstract

1,198,469. Automatic exchange systems. AUTOMATIC TELEPHONE & ELECTRIC CO. Ltd. 28 Aug., 1968 [10 Nov., 1967], No. 51213/67. Heading H4K. In a circuit arrangement for connecting individual ones of a large number of equipments to individual ones of a small number of equipments, the large number of equipments are divided into groups and an equipment of the large number requiring connection to an equipment of the small number initiates a demanding condition appropriate to its group and each of the small number of equipments which is free and not being offered to a group of higher priority is offered to all equipments of that group. An arrangement involving connections between 200 registers and three translators is detailed. The registers are divided into five groups of forty registers. A three column by five row array of selecting relays is provided, the columns corresponding to the translators and the rows to the groups. Each group having at least one register requiring a connection to a translator marks a corresponding row and each translator which is free marks a column. The relays at the intersections of the marked rows and columns are enabled but each column of relays is interconnected to form an allotting chain such that in each column only the enabled relay of highest priority (as determined by the wiring of that chain) establishes a holding path. Thus up to three selecting relays, one in each column associated with a free translator, are operated. The operated selecting relays may be associated with the same or different groups (of registers). Each register has three connecting paths, one to each translator, controlled via intermediate relays by three connecting relays. Within each register the three connecting relays are interconnected to form an allotting chain and within a group of registers further allotting chains interconnect one relay of each register. These two 'orthogonal' sets of allotting chains avoid the simultaneous operation of two connecting relays in the same group. When the selecting relays are operated one, two or three connecting relays associated with different groups and different translators are operated to establish simultaneous connections between those groups and translators. Chain fail relays which initiate an alarm when an allotting chain is broken without a relay in that chain being operated are provided.