System för överföring av textinformation till en ADSI- kompatibel telefon via ett allmänt växelförsett telefonnät

摘要

A telephone display system (10) for communicating data via a service circuit node (11) connected to a PSTN (13) for presentation by a visual display (26) connected to an Analog Display Service Interface (ADSI)-compatible telephone (14). In response to a service selection signal carried by an incoming telephone line (21), the service circuit node (11) generates information signals containing textual information and telephone instructions. The service circuit node (11) also connects the incoming telephone line (21) to an adjunct processor (12) and sends the information signals to the adjunct processor (12). In response, the adjunct processor (12) modulates a carrier in accordance with the digital information signals and transmits the resulting analog information data over the telephone line (21). If the telephone instructions include an initial instruction for causing the ADSI-compatible telephone to enter a data mode, the adjunct processor also converts the digital initial instruction into an analog format for transmission over the telephone line. The visual display (26) enters the data mode and displays the textual information.