| 摘要 |
PURPOSE:To improve the efficiency of utilization of a circuit by transmitting a telephone number and a data answer signal to two bidirectional lines by frequency division, and a data signal to two directional lines. CONSTITUTION:A compound switchboard 1, data terminals 2 and 3, and telephone sets 4 and 5 are connected together; a data answer signal and a telephone signal are transmitted through two bidirectional lines 8a and 9a by frequency division, and a data is transmitted through the remaining two lines 8b and 9b. Further, a cross-point switch 13 for telephone set switching is provided in the complex switchboard 1 separately from that for data terminal switching, so data communication and telephone communication are performed simultaneously, improving the efficiency of utilization of the circuit. |
