TRANSMITTER AND DATA TRANSMISSION METHOD

PROBLEM TO BE SOLVED: To confirm the normality of a received path and to easily learn terminal identification information with respect to a transmitter that is connected via a synchronous computer to a transmitter to which a terminal is connected via an asynchronous network and with respect to a data transmission method. SOLUTION: The transmitters to which terminals are connected via the asynchronous network are mutually connected by the synchronous network, the sender transmitter converts asynchronous data from the sender terminal into synchronous data, transmits the converted data to a plurality of transmission lines at the same time, the destination transmitter selects a plurality of reception paths by the synchronous network, converts the received synchronous data into asynchronous data and transmits the data to the destination terminal. The transmitter 1 is provided with an understanding confirmation frame notice section 10 that transmits an understanding confirmation frame for a prescribed period, an understanding confirmation frame transmission means including a transmission line data transmission section 2 or the like, an understanding confirmation table 8 storing a reception time corresponding to a reception path of the understanding confirmation frame received via the synchronous network, and a reception path discrimination section 7 that discriminates occurrence of the reception path when a difference between the reception time and a current time resulting from a prescribed period exceeds a prescribed value and transmits a reception path switching instruction to a reception path selection section 6.