What is full duplex vs. half duplex, and what is half duplex, full duplex, half duplex?

1. Full duplex communication allows data to be transmitted simultaneously in two directions, which is equivalent to the combination of two simplex communication modes in terms of capabilities. Full-duplex means that signals can be transmitted simultaneously (instantaneously) in both directions (ab and b a). Refers to the simultaneous synchronization of a b and b a, which is instantaneously synchronized.

2. Half-duplex data transmission means that data can be transmitted in two directions of a signal carrier, but cannot be transmitted at the same time.

For example, using technology with half-duplex transmission on a local area network, a workstation can send data on and then receive data immediately on the direction from which the data has just been transmitted. Like full-duplex transmission, half-duplex consists of a bidirectional line (the line can pass data in both directions).

Full-duplex can be understood as receiving data and sending data outward at the same time, but half-duplex is receiving data in time A and sending data in time B.

The two can't be done at the same time, in addition to the network card, what about those devices that are duplex?

Take the walkie-talkie, for example, it is a typical half-duplex: speaking and listening cannot be done at the same time, either speaking or listening. It's a typical full-duplex: speaking and listening at the same time.

There is no need to understand it now. When the 10M network card is used, it is divided into full-duplex and half-duplex.

The differences are as follows:

1. Simplex data transmission only supports data transmission in one direction; Only one party can receive or send information at the same time, and two-way communication cannot be achieved, for example: television, radio.

2. Half-duplex data transmission allows data to be transmitted in two directions, but at a certain time, data is only allowed to be transmitted in one direction, which is actually a simplex communication that switches directions; Only one party can receive or send information at the same time, and two-way communication can be achieved. Example: Walkie-talkie.

3. Full-duplex data communication allows data to be transmitted in two directions at the same time, therefore, full-duplex communication is a combination of two simplex communication modes. It requires that both the sending device and the receiving device have independent receiving and transmitting capabilities; Messages can be received and sent at the same time to achieve two-way communication, for example: ** communication.

4. The dual full duplex of the network card means that the network card can receive data while sending data, and the two are synchronized, which is like we usually play **, and we can hear each other's voices while talking. Current NICs generally support dual full-time.

Full duplex means that we can send data and receive data at the same time, and the two are synchronized, which is like we usually play **, and we can hear each other's voices while talking. Current NICs generally support full-duplex.

Half duplex, the so-called half duplex refers to a period of time, only one action occurs, such as a narrow road, and only one car can pass, when there are two cars facing each other, in this case, only one car drives first, wait until the head of the other car drives again, this example vividly illustrates the original half duplex. Cause. Early walkie-talkies, early hubs, and other devices were based on half-duplex products.

With the continuous advancement of technology, semi-double unions have gradually withdrawn from the stage of history.

Simplex communication refers to the transmission of data on a communication line in a single direction.

1. The direction of data transmission is different.

1. Simplex: Data transmission is one-way.

2. Half-duplex: It can transmit a closed grip in two directions of a signal carrier, but it cannot be transmitted at the same time.

3. Full-duplex: It can be transmitted in both directions of the signal carrier at the same time.

Second, the data transmission mode is different.

1. Simplex: Among the two sides of the communication, one side is fixed as the sender end, and the other party is fixed as the receiving end. Information can only be transmitted in one direction, using a single transmission line.

2. Half-duplex: The transmitter and receiver at each end of the communication system are transferred to the communication line through the transceiver switch to switch the direction, therefore, a time delay will be generated.

3. Full-duplex: It has a data exchange processor similar to the PC CPU, which can identify the MAC address of the network equipment connected to each port of the switch, and can realize a point-to-point dedicated connection.

Third, the scope of application is different.

1. Simplex: used in the occasion of transmitting data in only one direction. For example, the communication between the computer and the printer is simplex mode because only the computer transmits data to the printer and not in the opposite direction.

2. Half-duplex: The computer and the display terminal work in half-duplex mode, at this time, the characters typed from the keyboard are sent to the terminal to be displayed at the same time as being sent to the host, instead of using the method of loopback.

3. Full-duplex: The method of independent sending line and receiving line between the microprocessor and the peripheral equipment can make the data transmission operation in both directions at the same time.

1. Different in natureFull-duplex.

Transmission means that the switch can also receive data while sending data, and the two are carried out synchronously, and the current switches support full duplex. There is only one action in a period of time, for example, a narrow road in a day, only one car can pass at the same time, when there are currently two cars crossing, in this case, only one car can cross first, and wait until the other car is the first to drive.

2. The speed is different:In full-duplex mode, the maximum speed of the network cable can reach more than 100 megabytes in half-duplex.

mode, the speed that the network cable can achieve is usually about 10 megabytes.

3. Different modes: Wheel sensitiveThe network cable in full-duplex mode can work in both full-duplex mode and semi-double-duplex mode; However, the network cable in half-duplex mode cannot work in full-duplex mode.

Half-duplex data transfer allows data to be transmitted in both directions, but at a certain point, data is only allowed to be transmitted in one direction, which is actually a simplex communication that switches directions; Only one party can receive or send information at the same time, and two-way communication can be achieved. Example: Walkie-talkie.

Full-duplex data communication allows data to be transmitted in both directions at the same timeTherefore, full-duplex communication is a combination of two simplex communication methods, which requires both the sending device and the receiving device to have independent receiving and transmitting chain capabilities, and can receive and send information at the same time to achieve two-way communication. Example: Communication.

Standard. RS-485 standard is a half-duplex communication protocol, RS-485 is suitable for both sending and receiving morning travel to share a pair of lines for communication, and also suitable for sharing a pair of lines between multiple points for bus networking.

RS-485 interface chips have been widely used in many fields such as industrial control, instruments, meters, multi-** networks, mechatronics products, etc. There are also more and more types of chips that can be used for RS-485 interfaces. How to find the most suitable chip among a wide variety of interface chips is a problem in front of every user.

The RS-485 interface has different requirements for chips and usage methods in different use occasions. What factors should users consider in the selection of chips and the design of circuits, due to the inherent characteristics of some chips, some faults in the communication of land calls and sales even need to be adjusted accordingly in the software. The RS-485 interface can be connected to both half-duplex and full-duplex communication modes.

The differences between full-duplex and half-duplex are:

1. Full-duplex allows data to be transmitted simultaneously in both directions.

2. Half-duplex allows data to be quietly transmitted upwards in two directions, but the data can only be transmitted in one direction at the same time, which is actually a simplex switch.

Full-duplex is a term for communication transmission. Communication allows data to be transmitted simultaneously between two parties, and it is equivalent to the combination of two simplex communication methods in terms of capabilities. Full-duplex means that signals can be transmitted simultaneously (instantaneously) in both directions (ab and b a).

Refers to the simultaneous synchronization of a b and b a, which is instantaneously synchronized.

Simplex means that Party A is only allowed to send information to Party B, and Party B cannot transmit information to Party A.

Full-duplex networks must be networked with switches. A switch is a dedicated bandwidth network device that contains a data exchange processor similar to a PC CPU, which can identify the MAC addresses of network devices connected to each port of the switch.

The ability to implement a dedicated point-to-point connection enables full-duplex operation. However, it is worth noting that if you want to achieve full duplex, the port of the switch cannot be connected to the hub, otherwise this port can only work in the half-duplex state.

In addition, the switch has the function of automatically recognizing the full-duplex and half-duplex status. A 10 100Mbps adaptive switch will detect the rate of devices connected to the port in the order of 100Mbps full-duplex, 100Mbps half-duplex, 10Mbps full-duplex, and 10Mbps half-duplex. If a transmission rate and duplex mode are successfully detected, the switch uses that mode for data exchange.