Abstract: An improved method and system for integrating voice telephone and data terminal devices in a single system is described. The present system may be incorporated with an existing telephone system without modification of the telephone system. The present invention includes means for monitoring a telephone line and upon detection of a ringing signal, the system monitors the telephone line for either a DTMF or CNG signal. Upon detection of either signal, an incoming call is routed to a series connected device such as a data terminal.