What are the differences between serial communication and parallel communication?

Serial and parallel port cables are used in a wide range of application scenarios in working life. Serial and parallel port communication are both interface standards used for data transmission, but they have some differences in physical connection, data transmission method, transmission rate and application scenarios. Through these differences, we can see how the parallel interface, serial interface, USB interface is gradually updated iteration. We can also better choose the data transmission cable that suits us.

The physical connection is different:

1. Serial communication: Serial communication uses a serial connection, i.e., data is transmitted sequentially one by one, using a small number of pins for data transmission. Common serial interfaces are RS232, RS485, RS422, etc., of which RS232 is the most common standard.

2. Parallel port communication: Parallel port communication uses a parallel connection, i.e. multiple data bits are transmitted simultaneously, usually using multiple pins to transmit data. Common parallel port interfaces are Centronics, LPT (Printer Interface), etc.

Data is transferred in different ways:

1. Serial communication: Serial communication uses asynchronous transmission, i.e., each data frame is transmitted independently from each other, through the composition of start bit, data bit, parity bit and stop bit. Because it is asynchronous transmission, the transmission rate between data frames can be inconsistent during transmission.

2. Parallel port communication: Parallel port communication uses synchronous transmission, i.e., multiple data bits are transmitted at the same time and synchronized by a clock signal. The transmission rate of parallel port communication is usually relatively high because multiple data bits are transmitted at the same time, which improves the transmission efficiency.

The transmission rates are different:

1. Serial communication: the transmission rate of serial communication is generally low, usually below 115200 bps, although there are also specifications for high-speed serial ports, but the transmission rate is relatively limited. When transmitting over long distances, serial communication is faster than parallel communication because it can save space and cost due to its simple transmission line, which requires only one data line. In addition, serial communication can increase the transmission speed by increasing the transmission rate, such as using a higher speed serial bus.

2. Parallel port communication: The transmission rate of parallel port communication is generally higher, and it can reach a very high transmission rate, such as the IEEE 1284 standard parallel port communication can support the transmission rate up to 2MB/s. In the short distance transmission, the transmission speed of the parallel communication may be faster, because it can transmit multiple data bits at the same time in a short period of time. However, as the transmission distance increases, the signal interference increases and the error rate rises, at which time the advantages of serial communication technology for long-distance transmission are manifested. Moreover, parallel communication is limited by the number of physical channels, and it is difficult to significantly increase the transmission speed.

Application scenarios are different:

1. Serial communication: serial communication is mainly used in some long-distance, data transmission rate requirements are not high scenes. For example, PLC, sensors, instruments and devices in the field of industrial automation usually use serial port for data communication. In addition, serial communication is also commonly used in the connection between computers and external devices, such as serial printers, serial scanners and so on.

2. Parallel port communication: Parallel port communication is mainly used in the scenarios that require high-speed transmission of large amounts of data. The most typical application is the printer interface, through the parallel port can realize high-speed printing. In addition, some devices that need to transmit large amounts of data will also use parallel port communication, such as image acquisition cards, data acquisition cards, etc..

It should be noted that with the development of technology, serial communication is gradually replaced in some aspects by communication interfaces such as USB and Ethernet etc. USB interface has a higher transmission rate, greater compatibility and easier plugging and unplugging, so in most cases, people prefer to use the USB interface for data transmission. Parallel port communication, on the other hand, which does not support hot-plugging and low-rate transmission, is gradually being phased out, and modern computers are usually no longer equipped with parallel port interfaces.

As a professional manufacturer of high speed cables, Aiqun has been producing and stocking a large number of high speed cables such as MINI SAS cables, HD MINI SAS cables, SATA cables, industrial serial cables, etc., and supports customization. Among them, the USB serial cables produced by Aiqun Industry support RS232 standard, built-in FT232 chip, compatible with a variety of operating systems, and can be widely used in various fields and scenarios. For business cooperation, please contact the following staff:

Mr. Wang Tel: 13713335011; Email: wym@oikwan.com.cn

Mr. Peng Tel: 15797958662; Email: pengjian@oikwan.com.cn