An overview with Serial Data Speaking

Even with the widespread use of Universal Serial Bus (USB) ports, for many of our customers who use converters, serial ports remain an important interface. Not just on computers, but additionally digital camera models, printing equipment, modems and a wide variety of industrial automation network equipment, continue to utilize serial port connectivity. (Although, if you examine computers manufactured in the last few years, you'll probably find only one serial port alongside, on some models, a similar port.)

One of the great benefits of serial communications is the simplicity achieved by taking 8-bit bytes and transmitting them one bit at a time down an individual wire. This helps to keep both cabling costs low and the controlling communications protocol simple. AliBaba Dastaan E Kabul Watch Online Obviously the trade off is that transmitting 8 bits serially, in place of in parallel, is eight times slower! (Remember that parallel ports were developed after serial ports.

How do serial communications actually work? Well, although we mentioned the serial transfer of 8 bits on the wire, in fact control bits are also transmitted. A 'start' bit to point data is arriving, a 'stop' bit to point data is finished, and an (optional) parity bit.

The 'electronic brains' behind this data transmission is just a dedicated silicon chip called a 'Universal Asynchronous Receiver/Transmitter' (UART). This chip is a software between the inner computer bus's parallel communications, and the serial ('Com') port. Some UART chips can cache significant levels of data from the computer bus while simultaneously transmitting onto standard serial ports at rates of up to approx 115 kbps.

The serial port connectors used today contain 9 or 25 pins, with the pin assignments indicating a youthful age of modem to computer connectivity. The legacy of getting dedicated pins for transmitting, receiving and other control functions, allows serial data to be transmitted and received simultaneously i.e. completely duplex.

Naturally, full duplex communication is a great benefit but only when both transmitter and receiver can optimize the levels of data transmitted, and the full time intervals in which this is done. AliBaba Dastaan E Kabul Watch Online This important function is recognized as 'flow control' and is implemented with one device tell the other when and when to not send data, such as generally in most USB to RS485 or RS232 to RS485 converters.

In the serial communications world the specific hardware pins assigned to the function are: Data Terminal Ready (DTR) and Data Set Ready (DSR), Request To Send (RTS), and Clear To Send (CTS). By monitoring these lines the unit mounted on the computer can answer an immediate increase in data (beyond that of its cache to handle) by lowering the 'Clear To Send' (CTS) pin signal, comprehending that the computer monitoring its CTS pin will dsicover the dropped signal, and stop sending data.

It's this ability to steadfastly keep up a clean data flow that is highly valued in devices that convert between, for example, USB to serial RS232. High speed USB data communicating with the much slower RS232 interface needs careful handling.