Multiplexer is a device that uses multiplexing technology to load multiple low-speed or narrow-band data from multiple terminals onto a high-speed or broadband communication line for transmission. The function of the multiplexer, in layman's terms, is used to select the digital signal path, so it is sometimes called a data selector.
significance
The purpose of using a multiplexer is to make full use of the capacity of the communication channel and greatly reduce the cost of the system. For example, for a pair of telephone lines, its communication frequency band is generally above 100kHz, and the frequency band of each telephone signal is generally limited to below 4kHz. At this time, the capacity of the channel is far greater than the information transmission volume of a phone.
effect
Using multiplexers, multiple channels of data information can share one channel. When the data stream on the multiplexed line is continuous, this sharing method can achieve good results. Obviously, this is more economical than using a communication line for each terminal. Multiplexers are always used in pairs. One continuous terminal, the other near the host, its function is to separate the received composite data stream according to the channel, and send them to the corresponding output line, so it is called a demultiplexer.