Circuit arrangement for centrally controlled telephone exchange installations having carrier frequency devices

Abstract

Abstract A circuit arrangement for centrally controlled telephone exchange installations having carrier frequency channels is described. The centrally controlled exchange has multiple stage switching matrices to the terminals of at least a portion of which are connected carrier frequency channels. The carrier frequency channels are grouped, and as groups are subject to continuous functional control, by a pilot supervision device. The line finder is developed as a central occupation memory with appropriate logical connections with the central control unit. The occupation memory reproduces the occupation condition of all parts of the switching matrix. A blocking signal is transmitted from the appropriate pilot supervision device, when a disturbance is noted in one of the carrier frequency channels in the group of channels associated therewith, to the occupation or line finding memory. This causes the memory to simulate the condition therein, that the switching matrix terminals to which the carrier frequency channels are connected are busy. This arrangement eliminates the need for occupation current circuits and associated switching devices, which are otherwise needed to test and block disturbed carrier frequency channels.

Inventors

• 👤 Gunther Lohr
• 👤 Franz Loffler
• 👤 Alfred Schaller

Bibliographic Details