PURPOSE: To decrease the burden of a data processing unit and to decrease the number of input part by transmitting a channel selection signal from a recorder and transmitting an analog signal by time division multiplexing.

CONSTITUTION: A channel selection signal is outputted successively from the channel selecting part CEX of a recorder REC to a data processing unit DP. The unit DP receives the channel selection signal in a channel input part CRE, and inputs the same to a processor PRO. Further, the processor PRO reads the data of the corresponding channel from a memory according to the channel selection signal, converts the same to an analog signal with a DA converter D/A and transmits the same toward the recorder REC. The recorder REC receives the analog signal in a signal input part IN and distributes the same to each channel according to the channel selection signal from the part CEX. Further the distributed analog signal is inputted to the delay part DL of the corresponding channel.