To function properly, serial ports rely on a special controller chip, the Universal Asynchronous Receiver/Transmitter ( UART) which supports a relatively high data transfer rate, reaching 115,000 baud (bit/s). In addition, there are several control lines. They are the lines for transferring data from the terminal (PC) to the communication device and back. Hence, the name “serial port”.Ī serial port has two lines through which the actual data is transmitted.
The sequences of bits are grouped into data series beginning with a start bit and ending with a stop bit.
In contrast to a parallel (LPT) port, a serial port transmits data bit by bit over a single line rather than several lines at a time. Serial and parallel interfaces are two different types of computer ports.
However, a modern COM port is no longer a bulky interface located on the back panel of the system unit but a completely software solution.
Users still have to make the port configurations as they would do with a physical serial port. This makes it possible to ensure compatibility between legacy serial software and modern equipment.Īs for the way you manage your COM ports, it does not change significantly. And all serial apps communicating with a remote peripheral over a virtual serial port recognize the interface as a hardware one. In this case, remote serial peripherals are accessed via a virtual COM port created in your local system by a specialized app.
Virtual Serial Port Driver, Virtual Serial Over Ethernet, etc.), a remote serial device can be emulated on your local PC in such a way that you can communicate with it as though it were connected directly to your machine. Now, thanks to some dedicated software (e.g.
A virtual COM port is a solution if there’s a lack of real serial ports in your system. What’s more, GPS receivers have increasingly been installed inside of devices, meaning the cable connection is no longer efficient.Ī virtual serial port is a special software package that emulates a physical COM interface in software, which allows you to add serial ports to your PC without using additional physical hardware like expansion cards, etc. Now most modern computers are equipped with USB ports instead of COM interfaces. In order to set up serial communication, a user needed to specify a correct port number and the speed of data transmission. This is due to the fact that initially almost any equipment, including GPS receivers, was external, and its connection to the computer was established via a serial cable attached to one of the PC’s hardware ports. However, modern standards of compatibility between serial equipment and its controlling software have been formed for quite some time around the concept of COM ports which are now seen as archaic. A COM port has been replaced by USB - a more modern method which does not require special knowledge for implementation. Today serial port communications are not that common as they once were. However, a serial mouse as well as other peripheral devices can also interact with a computer via a serial interface. If the parallel port was mainly used to connect printers, the COM port (by the way, COM is short for communication) usually worked with telecommunication devices such as modems. However, its scope of application was somewhat different from that of the parallel port. On first machines, the COM port was used for connecting peripheral devices. The serial port appeared long before personal computers of the IBM architecture were introduced.