| 摘要 |
A data-communication apparatus for performing data communication by using a modem with a plurality of modulation/demodulation modes, operated in a mode specified from among the plurality of modulation/demodulation modes, is capable of distinguishing signals in a plurality of modulation/demodulation modes which may be simultaneously received by the data-communication apparatus. Specifically, a frequency-detection function provided in a modem is used to detect the frequency of the V.8 protocol signal CI while the modem is receiving the signal in the V.21 mode in the T.30 protocol. When the frequency is detected, a CPU causes the mode of the modem to switch to the V.8 mode for signal reception.
|
