ELECTRONIC KEY TELEPHONE SYSTEM

摘要

PURPOSE:To improve the side tone for normal talking and data communication by a MODEM by discriminating a carrier of data communication so as to switch the channel depending on the voice signal private channel and the data signal private channel. CONSTITUTION:A carrier discriminating means 11 discriminates a voice signal or a data signal and a channel switching means 12 switches a channel, then the voice signal is used for one-way communication for transmission or reception, and the data signal is used for two-way communication by a 2/4-wire converting means 20 taking notice of two-frequency of transmission only. This means that the design is far facilitated than the voice signal and the data signal used for the conventional two-way communication by the two-way 2/4-wire conversion means taking notice of all frequencies (nearly 300Hz-4kHz) and the performance of side tone is improved.