The fundamentals associated with Serial Data Marketing communications

Despite the widespread use of Universal Serial Bus (USB) ports, for a number of our customers who use converters, serial ports are still an essential interface. Not just on computers, but in addition digital camera models, printing equipment, modems and a wide range of industrial automation network equipment, continue to utilize serial port connectivity. (Although, if you examine computers manufactured within the last couple of years, you'll probably find just one serial port along side, on some models, a similar port.)

One of the great advantages of serial communications is the simplicity accomplished by taking 8-bit bytes and transmitting them one bit at a time down just one wire. This keeps both cabling costs low and the controlling communications protocol simple. AliBaba Dastaan E Kabul Watch Online Of course 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 can 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 indicate data is arriving, a 'stop' bit to indicate data is completed, and an (optional) parity bit.

The 'electronic brains' behind this data transmission is a dedicated silicon chip known as a 'Universal Asynchronous Receiver/Transmitter' (UART). This chip is a program between the interior computer bus's parallel communications, and the serial ('Com') port. Some UART chips can cache significant amounts of data from the computer bus while simultaneously transmitting onto standard serial ports at rates all the way to 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. completely duplex.

Naturally, full duplex communication is a superb benefit but only if both transmitter and receiver can optimize the amounts of data transmitted, and enough time intervals by which this is done. AliBaba Dastaan E Kabul Watch Online This important function is called 'flow control' and is implemented by having one device tell one other when and when to not send data, such as in many USB to RS485 or RS232 to RS485 converters.

In the serial communications world the precise hardware pins assigned to this 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 to the computer can answer a sudden increase in data (beyond that of its cache to handle) by lowering the 'Clear To Send' (CTS) pin signal, knowing that the computer monitoring its CTS pin will dsicover the dropped signal, and stop sending data.

It is this ability to keep a smooth data flow that's 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.