调制解调器又叫Modem,它是可以把计算机发送的数字信号转换为适应模拟信道传输的信号(调制),再把经过调制后的信号还原成数字信号(解调)的设备。 调制解调器的通信方式有三种。 单工方式 通信双方只能设定一个固定的方向传输数据,即一端固定为数据发送端,另一端则固定为数据接收端。 半双工方式 通信双方可以进行双向的数据传输,但各端不能同时发送和接收。允许各端既可以发送数据,又可以接收数据, Modem, also known as Modem, is a device that converts a digital signal sent from a computer into a signal (modulation) that is adapted to the analog channel and then restores the modulated signal to a digital signal (demodulation). There are three modes of modem communication. Simplex mode of communication Both parties can only set a fixed direction of transmission of data, that is, one end of the fixed data sender, the other end is fixed as the data receiver. Half-duplex communication Both parties can perform bidirectional data transmission, but each side can not send and receive at the same time. Allow each end can send data, but also can receive data,