A data transmission system avoids charging of line utilization fees when it is attempted to send data to a destination incapable of receiving the data and can be readily operated even by an operator having little technical knowledge. By storing function information relating to the terminals of a plurality...http://www.google.com.au/patents/US5095445?utm_source=gb-gplus-sharePatent US5095445 - Data communication system capable of communicating on-line with communication terminal equipment of a plurality of types
