GB1009069A - Improvements in or relating to telecomunications systems - Google Patents

Abstract

1,009,069. Automatic exchange systems. SIEMENS & HALSKE A.G. Oct. 1, 1962 [Sept. 29, 1961], No. 37020/62. Heading H4K. In a network comprising main and subexchanges in which tickative equipment is provided at the main exchange for all calls outgoing from the network, only the number of a calling subscriber within a sub-exchange is determined thereat, and the number of the sub-exchange concerned is determined at the main exchange by an identifier which serves also to identify calling subscribers directly connected to that exchange. As shown, groups of ring-cores H, Z, E corresponding to the hundreds, tens and units digits of subscribers' numbers are threaded selectively by loops such as AS211. When A.C. is applied to the relevant loop the groups of cores are effective in turn to control receivers S1. . .S0 and provide a record in a store SP. In the case of a line incoming from a sub-exchange the loop such as AS21 threads a core in one or more of the groups H, Z, E to identify the sub-exchange, and also a core VAK2 which results in the passage of a signal to the control unit ASK to stop the identifying operation when the appropriate number of digits (less than the full number) have been determined. In another embodiment, Fig. 4 (not shown), the identifying current flows over the c-wire instead of over the talking wires of the connection.