CIRCUIT FOR SWITCHING INSTALLATIONS OF CENTRAL COMMAND TELECOMMUNICATIONS, OVERALL INSTALLATIONS OF TELEPHONE CENTRAL-MULTIPLEX TEMPORAL-PCM

摘要

Line trunk groups connected with doubled switching matrix via two link line systems and exhibiting, among other things, one partial switching matrix each and one non-centralised control device each are subdivided into two categories. Concentrators are always connected to one line trunk group each of both categories. To load the control devices and the concentrators with new programs and/or data, one processor continues switching operations in that only the control devices of the first category remain connected to it and in that the concentrators continue to establish connections only via the line trunk groups of the first category. The other processor is connected to the control devices of the second category and carries out load procedures for and via these. After that, connections are established via line trunk groups of both categories with the aid of both processors and then the line trunk groups of the first categories are barred against new allocations and only connections still being established and existing are continued. After that, the other processor loads the one processor and the latter loads the line trunk groups of the first category. Avoidance of total failure of the system when changing programs, data and/or processors. IMAGE