COM 1 is the technical standard of serial binary data exchange interface between DTE and DCE. Many mobile phone data lines or logistics receivers are connected to computers through COM ports.
There are three reasons for the general disconnection. One is the virus attacked in the computer, the other is the problem of LAN router or line, and the third is the problem of network provider. Routers (including router itself, network cable and computer problems) usually lead to network disconnection and need to be solved by themselves, while routers (including modems, etc. ) is solved by the network provider.
According to electrical standards and protocols, serial communication interfaces are divided into RS-232-C, RS-422, RS485 and USB. RS-232-C, RS-422 and RS-485 standards only specify the electrical characteristics of the interface, and do not involve plug-in programs, cables or protocols. USB is a new interface standard developed in recent years, which is mainly used in the field of high-speed data transmission.
The RS-232 interface conforms to the serial data communication interface standard formulated by EIA. Originally numbered EIA-RS-232 (abbreviated as 232, RS232). It is widely used to connect peripheral devices of computer serial interface. Connecting cables and mechanical electrical characteristics, signal function and transmission process.
Extended data:
Similar interface standards:
1.RS-422: In order to solve the problem of short communication distance and slow speed of RS-232, RS-422 defines a balanced communication interface, which increases the transmission rate to 10Mb/s, extends the transmission distance to 4,000 feet, and allows 10 receivers to be connected through a balanced bus. RS-422 is a one-way balanced transmission specification for single-machine transmission and multi-machine reception. It is called TIA/EIA-422-A standard.
2.RS-485: In order to expand the application scope, EIA has formulated the RS-485 standard on the basis of RS-422 in 1983. It adds multipoint and bidirectional communication functions, allowing multiple transmitters to connect to RS-485. The same bus. At the same time, the driving function and collision protection characteristics of the transmitter are increased, and the * * * mode range of the bus is expanded, which is later called TIA/EIA-485-A standard.
3.SATA interface: The full name of SATA is serial advanced technology attachment, which is a serial hardware driver interface based on industry standards. It is a hard disk interface specification proposed by Intel, IBM, Dell, APT, Maxtor and Seagate.
Baidu Encyclopedia-Device Manager
Baidu Encyclopedia -RS232 Interface
Baidu encyclopedia-serial port
Baidu encyclopedia-dropped line