rs232 Serial port Communication Principle Serial port is a very common device communication protocol on the computer (not to be confused with the Universal Serial Bus or USB).
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Most computers contain two RS232-based serial ports. Serial port is also a common communication protocol for instrumentation equipment; Many GPIB compatible devices also come with RS-232 ports. At the same time, the serial communication protocol can also be used to obtain the data of the remote acquisition device.
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The concept of serial communication is very simple, the serial port sends and receives bytes in bits. Although slower than byte-by-byte parallel communication, serial ports can use one wire to send data while receiving data with another wire. It is simple and enables long-distance communication. For example, when IEEE488 defines the parallel traffic state, it stipulates that the equipment line should not exceed 20 meters, and the length between any two devices should not exceed 2 meters; For serial ports, the length can reach 1200 meters. Typically, serial ports are used for transmission of ASCII characters.