Abstract: In configurable intelligent primary multiplexers the individual 64 kbits/s channels of several incoming and outgoing PCM-links are to be re-arranged with the aid of a commercially available integrated circuit in such a manner that the desired channel configuration is achieved. The signalling information belonging to the individual channels is transmitted for all intelligence channels of a link in the time slots No. 16 of the superframe, each time slot containing the signalling information of two channels. In order to be able to perform the re-arrangement of the signalling information in parallel to that of the intelligence channels without the continuous help of a processor the signalling bit stream lined-up by an ancillary device is converted in such manner that the signalling information of the individual 64 kbit/s channels is in identically numbered time slots as they are allocated to the corresponding intelligence channels.