What is the data communication method _Shang ping China focuses on high quality website construction

The data communication mode refers to whether the channels of the communication parties are one-way channels, two-way channels or multiple channels, and Website production Whether the data is serial communication or parallel communication.

1. Simplex, half duplex and full duplex

In point-to-point communication, data communication can be divided into simplex, half duplex and full duplex according to the direction of signal transmission on the channel, as shown in Figure 2-6

(1) Simplex communication: see Figure 2-6 (a). It is characterized by one-way transmission of the channel, that is, data signals can only be transmitted in one direction, and the transmission direction of the signal cannot be changed at any time. Such as TV signal transmission, radio broadcasting, remote control control, etc., this simplex communication is generally not used in computer network communication.

(2) Half duplex communication: see Figure 2-6 (b), which is characterized by that although the channel is two-way transmission, the receiving and sending must be conducted alternately, that is, the transmission can only be in one direction at a time. Transmitters and receivers at both ends of the communication system are transferred to the communication line through the receiving/sending switch to switch the communication direction. This communication mode will cause a certain time delay between the two parties.

For example, walkie talkie communication, and the early traditional bus Ethernet is a typical half duplex communication.

(3) Full duplex communication: see Figure 2-6 (c). The characteristic channel is not only two-way transmission, but also receiving and sending can be carried out at the same time, that is, data transmission and receiving are shunted and transmitted by two transmission lines respectively. For example, the communication of telephone system is a typical full duplex communication application. In computer network communication, full duplex communication technology is also applied more often.

2. Serial communication and parallel communication

Data communication can also be divided into serial communication and parallel communication according to the number of bits in a data transmission. The former refers to the communication of transmitting a word bit by bit through a transmission line; The latter refers to the communication of transmitting one space at a time through a group of transmission lines. If the word length is 8, 8b will be transmitted at a time, as shown in Figure 2-7.

Serial communication and parallel communication

Compared with the two, the parallel communication mode has a high data transmission rate, but it is not suitable for long-distance data communication. Because the parallel signal is easy to cause different delay and distortion when it is transmitted and amplified over a long distance. This kind of parallel communication mode is more used in the communication within the computer, as well as the data communication between the computer and the parallel printer.

Although the communication rate of serial communication is low, it is easy to realize and can save a lot of equipment investment. It is a main communication mode currently, especially in the long-distance digital communication system, serial communication mode is often used.

What is the data communication mode

Date：2015-06-23 Source: Shangpin China Type: website encyclopedia
Word Size： small medium big

+86 10-60259772