Patent EP-0058750-B1 (EP)
IPC: H04Q11/04
Filed: 1981-10-15
Granted: 1985-07-03
Abstract: 1. A circuit arrangement for centrally controlled t.d.m. telecommunications exchange systems, in particular PCM telephone exchange systems, with a multi-stage switching network (K) which has t.d.m. inputs and t.d.m. outputs, and with a plurality of connection devices (LTG1, LTG2, LTGn) which serve to connect t.d.m. connection lines, analogue connection lines and/or analogue subscriber lines, each of which (e.g. LTG1) is connected to a t.d.m. input (A1) and a t.d.m. output (A2) of the switching network, and with at least one central control unit (ZW) and with a plurality of decentral control devices (TE1, TE2, TEn) which are individually assigned to the connection devices (LTG1, LTG2, LTGn) and which are connected to the control unit (ZW) via data channels (m ...) which are switched through via the switching network (K), are constantly maintained in readiness for transmission, and which extend via the switching network (K) in such manner that each of the t.d.m. inputs (A1) and each of the t.d.m. outputs (A2) of the switching network (K), and each of its t.d.m. intermediate lines carries at least one data channel, and with a control unit-connection device (MB/ML) which is assigned to the control unit (ZW) and is connected thereto and which is connected to the switching network (K) in the same way as the other connection devices (LTG1, LTG2, LTGn), and via which the control unit (ZW) exchanges data with the control devices (TE1, TE2, TEn) of the other connection devices (LTG1, LTG2, LTGn) in a system of data exchange which includes all the data channels and which serves to monitor the functioning capacity of all the t.d.m. intermediate lines of the switching network (K), characterised in that the switching network (K) is constructed from uni-directional t.d.m. switching devices (RZE R RZA) and uni-directional t.d.m. intermediate lines, that the control unit connection device (MB/ML) is connected via a t.d.m. input and a t.d.m. output of the switching network (K) only to one t.d.m. switching device of the first switching stage (RZE) and one t.d.m. switching device of the last switching stage (RZA), that the data channels, which are switched through from the control unit (ZW) to the control devices (TE1, TE2, TEn) extend via t.d.m. intermediate lines which extend out from the t.d.m. switching device, connected to the control unit connection device (MB/ML), of the first switching stage (RZE) to each of the t.d.m. switching devices which are located at a specific interface (R) within the switching network (K), that the data channels which are switched through from the control devices (TE1, TE2, TEn) to the control unit (ZW) extend via t.d.m. intermediate lines which converge from each of the aforementioned t.d.m. switching devices at the specific interface (R), to the t.d.m. output, which is connected to the control unit connection device (MB/ML), of the t.d.m. switching device of the last switching stage (RZA), that the data channels which are switched through from the control devices (TE1, TE2, TEn) to the control unit (ZW) extend via t.d.m. intermediate lines which extend out from each of the t.d.m. switching devices of the first switching stage (RZE) to all the t.d.m. switching devices which are located at the specific interface (R) within the switching network (K), and that the data channels which are switched through from the control unit (ZW) to the control devices (TE1, TE2, TEn) extend via t.d.m. intermediate lines which converge from all the t.d.m. switching devices at the specific interface (R) within the switching network (K), to each of the t.d.m. switching devices of the last switching stage (RZA).