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:
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.