In telecommunication, the process of sending data sequentially over a computer bus is called as serial communication , which means the data will be transmitted bit by bit. While in parallel communication the data is transmitted in a byte 8 bit or character on several data lines or buses at a time. Serial communication is slower than parallel communication but used for long data transmission due to lower cost and practical reasons.
Serial communication — you are shooting a target using machine guns, where bullets reach one by one to the target. Parallel communication - you are shooting a target using a shotgun, where many number of the bullets reach at the same time. RS is a standard protocol used for serial communication, it is used for connecting computer and its peripheral devices to allow serial data exchange between them.
As it obtains the voltage for the path used for the data exchange between the devices. It is used in serial communication up to 50 feet with the rate of 1. The microcontrollers are not able to handle such kind of voltage levels, connectors are connected between RS signals.
The ratings and specification changes with the change in equipment model. RS works on the two-way communication that exchanges data to one another. This is the whole process through which data transmission takes place. For example: The signals set to logic 1, i. Among them are correct baud rate setting for the device, proper software configuration and proper cabling.
There is one very simple test that will help simplify the task of troubleshooting your RS system, which is sometimes called the "Loop-Back" test. Basically, this test will verify that your PC's serial port is working properly, and that the RS software that you are using is operating correctly, and that you are connected to the proper port. It is a common mistake to connect a serial device to the printer port, since many believe this to be a pin RS port. One important thing to remember is that an RS port on an IBM or compatible PC is always a male connector, and may be either 9 or pin.
A printer port is always a pin female connector. To perform a "Loop-Back" test, follow these simple steps. It is, however, similar for other computers. Remember, a PC's RS port can be 9-pin or pin, but will always be a male connector containing pins, not sockets. If necessary, consult your computer's manual, or contact their technical support department. A magnifying glass may be required to read the numbers on the inside base of the connector.
For example, if the data is , for Even parity, the serial port sets the parity bit as 1 to keep the number of logic-high bits Even. For Odd parity, the parity bit is 0 so that the number of logic-high bits is Odd. Mark parity simply sets the parity bit to logic-high and Space sets the parity bit to logic-low, so that the receiving party can determine if the data is corrupted. Stop bits are used to signal the end of a communication packet.
This also helps to synchronize different clocks on the serial devices. Handshaking is also called "Flow Control". The main purpose of Handshaking is to prevent receiver overloading. By using Handshaking signals, receivers will be able to tell the sending device to pause data transmission if the receiver is overloaded. There are three types of handshaking: Software handshaking, Hardware handshaking and Both.
The receiver sends these control characters to pause transmitter during communication. The drawback of Software handshaking is that these two control characters can not be used in data. This is quite important when you are transmitting Binary data as you might need to use these two codes in your data. DCD Data Carrier Ready is used by the modem when a connection has been established with remote equipment, while RI Ring Indicator is used by the modem to indicate a ring signal from telephone line.
Binary is the Base-2 numbering system. One byte of data consists of 8 binary digits, from to Hexadecimal is the base system, which consists of 16 numbers: 0 to 9 and the letters A to F decimal number The Hexadecimal numbering system is useful because it can represent every byte as two consecutive hexadecimal digits, and it is easier for humans to read Hexadecimal numbers than Binary numbers. Most of the manufacturers use Hexadecimal in their protocol documentation.
It is simple to convert a value from Hexadecimal to Binary. Just translate each Hexadecimal digit into its 4-bit binary equivalent. Hexadecimal number F3 equals Binary number Decimal refers to numbers in base 10, which is the numbering system we use most in everyday life.
It's not as easy as Hexadecimal and Octal to converter Decimal to Binary number, but it is easier for us to understand Decimal. Octal refers to the base-8 numbering system, which uses just eight unique symbols 0 to 7. Programmers often use Octal format because it is relatively easy for people to read and can easily be translated into binary format: each Octal digit represents 3 binary digits. Octal number 73 equals to Binary number ASCII codes both readable and unreadable are widely used in communications, such as Modem communications.
Many serial protocols use checksum additional bytes added at the end of the data string to check the data integrity, as errors might occur during data transmission.
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