Basic principles involving Serial Data Sales and marketing communications

Despite the widespread usage of Universal Serial Bus (USB) ports, for quite a few customers who use converters, serial ports remain an important interface. Not only on computers, but also 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 within the last several years, you'll probably find just one serial port along side, on some models, a parallel port.)

One of many great advantages of serial communications may be the simplicity achieved by taking 8-bit bytes and transmitting them one bit at the same time down an individual wire. This keeps both cabling costs low and the controlling communications protocol simple. AliBaba Dastaan E Kabul Watch Online Needless to say the trade off is that transmitting 8 bits serially, as opposed to in parallel, is eight times slower! (Remember that parallel ports were developed after serial ports.

Just how do serial communications actually work? Well, although we mentioned the serial transfer of 8 bits on the wire, actually control bits will also be 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 an interface between the interior computer bus's parallel communications, and the serial ('Com') port. Some UART chips are able to cache significant amounts of data from the computer bus while simultaneously transmitting onto standard serial ports at rates as high as approx 115 kbps.

The serial port connectors being 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. in full duplex.

Naturally, full duplex communication is a good benefit but as long as both transmitter and receiver can optimize the amounts of data transmitted, and the full time intervals in which this really is done. AliBaba Dastaan E Kabul Watch Online This important function is known as 'flow control' and is implemented by having one device tell one other when and when never to send data, such as generally in most USB to RS485 or RS232 to RS485 converters.

In the serial communications world the particular 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 device attached with the computer can react to a sudden escalation in data (beyond that of its cache to handle) by lowering the 'Clear To Send' (CTS) pin signal, realizing that the computer monitoring its CTS pin will see the dropped signal, and stop sending data.

It's this ability to maintain a clean data flow that is highly valued in devices that convert between, as an example, USB to serial RS232. Top speed USB data communicating with the much slower RS232 interface needs careful handling.