The basic principles regarding Serial Data Marketing and sales communications

Despite having the widespread utilization of Universal Serial Bus (USB) ports, for many of our customers who use converters, serial ports are still an important interface. Not just on computers, but in addition cameras, printing equipment, modems and a wide selection of industrial automation network equipment, continue to take advantage of serial port connectivity. (Although, in the event that you examine computers manufactured in the last several years, you'll probably find just one serial port along side, on some models, a simultaneous port.)

One of the great advantages of serial communications could be the simplicity attained by taking 8-bit bytes and transmitting them one bit at the same time down a single 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, rather than 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, in fact control bits may also be transmitted. A 'start' bit to indicate data is arriving, a 'stop' bit to indicate data is finished, and an (optional) parity bit.

The 'electronic brains' behind this data transmission is a dedicated silicon chip called a 'Universal Asynchronous Receiver/Transmitter' (UART). This chip is an interface between the inner computer bus's parallel communications, and the serial ('Com') port. Some UART chips have the ability to cache significant levels 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 used today contain 9 or 25 pins, with the pin assignments indicating an earlier 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 levels of data transmitted, and the full time intervals by which this really is done. AliBaba Dastaan E Kabul Watch Online This important function is called 'flow control' and is implemented with one device tell the other when and when to not send data, such as in most USB to RS485 or RS232 to RS485 converters.

In the serial communications world the specific 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 unit mounted on the computer can react to an immediate upsurge 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 see the dropped signal, and stop sending data.

It is this ability to keep up an easy 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.