Transit exchange for asynchronous data with unknown structure

Claim 1

In a transit exchange for the relaying of asynchronous data signals having an unknown character structure and data rate from sending terminal equipments to receiving terminal equipments with the aid of a control equipment, containing a computer, and a sampling means, common to a number of sending terminal equipments and arranged to work according to the time division multiplex principle, for sampling with the aid of sampling pulses the instantaneous values of the data signals received on each of a number of incoming lines from sending terminal equipments, and encoder means arranged to work synchronously with said sampling device, for encoding by means of successive processing of the sampling pulses whether the data signals have changed said value between two consecutive sampling pulses and, in correspondence therewith, for delivering an indication signal in the form of a code word having a specific number of binary bits which indicate the time position for the sampling pulse occurring after such change, the improvement comprising an intermediate memory means for storing the data bits serially in an addressed location assigned to the receiving terminal equipment, a decoding means connected to said intermediate memory for successively processing the binary bits to form indication signals which alter their value in accordance with the time position indicated by the code words, regeneration means assigned to receiving terminal equipments, and a read-out means arranged to work synchronously with said decoding means, for transferring the values of the indication signals cyclically from said decoding means to said regeneration means, and said regeneration means including means for forming from the values of the received indication signals data signals which change value in synchronism with the indication signals.