Telephone exchange with reduced connection time - assigned to line groups for connecting to translator

The telephone exchange has a given number of lines grouped into a group. Each group shares registers fewer in number than the given number of lines. A control device interrogates the registers via a single line to discover whether they are engaged or not. Both this interrogation and the switch-through between the register device and the translator take place in conjunction with a clocked selection device. The last step of this selection device is stored to allow resetting when one of the fault signals fails.