PURPOSE: To automatically executing a switching from a communication mode to a call mode by monitoring the existence of a synchronizing mode during a constant time after a call is terminated.
CONSTITUTION: In case of the terminating call for communication which is a purpose, even when a connecting is completed, the transmission of the synchronizing code, which is necessary to execute data communication, is not executed from the telephone set of an opponent side. Accordingly, a synchronizing code detecting means 15 does not generate a syncronizing code detecting signal since the synchronizing code is not inputted. A mode switching means 16 changes-over a mode switch 14 from the communication mode to the call mode since the synchronizing mode detecting means 15 does not detect the synchronizing mode within a prescribed synchronizing code monitoring time TS after a line connection completing signal DR is received. Thus, by monitoring the existence of the synchronizing code during the constant time after the call is terminated, the terminating call can be detected whether its purpose is the communication or the call with simple constitution and when the terminating call is for the the call, mode can be automatically switched to the call mode from the communication mode.
NIE KOICHI
HITOMI MASAHIRO
SHIHARA SHINJI
KURITA MASAHIRO
