Circuit arrangement for telecommunication exchanges, especially PCM time division telephone exchanges, with distributed switching networks connected to a central switching network

摘要

Line trunk groups connected to the central switching network via link connections and exhibiting one distributed switching network each and one group processor each are associated with one another in pairs. Within each line trunk group, on the one hand, line units for connecting the external lines and, on the other hand, link termination circuits for the link connections to the central switching network can be switched from the distributed switching network of the relevant line trunk group to that of the respective partner line trunk group. Line units and link termination circuits and intermediate-level processor with distributed switching network are equipped with three individual power supplies and three individual clock supplies per line trunk group. Line unit, intermediate-level processor with distributed switching network and link termination circuits operate in plesiochronous mode. In changeover mode, the clock supply of the switched-over line units receives master clock from the intermediate-level processor of the partner line trunk group. …IMAGE…