PURPOSE: To enable to transfer a great quantity of signal information economically, by transmitting signal and audio information through audio channels and distributing the audio information to a time sharing switch and the signal information to a communication path control device, in a PCM communication control system transferring a great quantity of signal information.

CONSTITUTION: The 1st and 17th frames of the 16th channel among 0∼31 channels, are constituted as a multiframe counter MC, and the transfer content of the 1st∼15th channels and the 17th∼31th channels is whether the audio information or signal information, is displayed corresponding to each channel with the control code C of the 2nd∼5th frames. In transferring the signal to outgoing line, with the transfer request from a communication path control unit SPC, a line control unit LCONT in a digital transfer interface control unit DTIC stores once the signal in a line memory unit LMEM, it instructs the synchronizing unit SYNCA when the time of delivery comes, and transmits the control code C to the transfer interface unit DTI by taking the code as 1, and transmits the signal from the unit LMEM at the period of signal transmission.