Abstract:
A distributor is disclosed for a centrally controlled telephone exchange enabling the control of bistables distributed in groups. The distributor receives from the central unit for a group of bistables to be controlled a control data item indicating the bistables to be set in position 1 and 0, and an inhibition data item indicating the bistables whose position must remain unchanged and serving to mask the elements of the control data corresponding to these bistables. The central unit function is thus limited to the elaboration and to the transmission only of the control data elements intended to certain components of an addressed group.
Abstract:
An electronic scanner is started by a central processor to asynchronously scan a number of lines. When the scanner detects a calling line, it stops and calls the processor. The processor then starts the scanner again to operate till it detects another calling line or reaches the last line to be scanned. It is possible with such a system that the scanner will not operate properly and the central processor will not be informed of this fact. The invention provides for check scanning, without event detection, but with a stop at specified addresses.
Abstract:
Subscribers'' line circuits and a linefinder are disclosed for use in a common control telephone exchange to determine the status of subscriber lines. Biasing potentials and switches in the line circuit together with logic circuits in association with the linefinder and the line circuits enable the combination to identify lines requesting service and those in faulty operating condition.