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Applications 👉 Teletypewriter devices. 👉 Demodulator applications. PC COM port interfacing. 👉 In embedded systems for debugging. 👉 Modems and printers. 👉 Handheld equipment 👉 CNC controllers,Software debuggers etc. 👉 Barcode scanners and Point of Sales (POS) terminals.

Disadvantages of RS232 👉 It doesn’t support full-duplex communication and it is a single-ended protocol which shifts the ground potential. 👉 Longer cable length introduces cross talk during serial communication. Hence, this protocol is restricted for long distance communication.

Advantages of RS232 👉 Simple protocol design. 👉 Hardware overhead is lesser than parallel communication. 👉 Recommended standard for short distance applications. 👉 Compatible with DTE and DCE communication. 👉 Low cost protocol for development.

Difference between RS232 and UART The main difference between RS232 and UARTis RS232 is a half-duplex communication protocol, whereas UART is a full duplex communication protocol. Microcontrollers don’t tolerate RS232 voltages and may be damaged. To avoid this, UART(Universal Asynchronous Transmitter Receiver) is used. It sends and receives the data in serial form. To do the level conversion of voltages, RS232 driver IC such as MAX232 is used between the UART and serial port.

Why to use Handshaking? To send and receive the information without loss of data, it is necessary to maintain robust communication between the transmitter and receiver. To do that, buffer is used. Buffer is a temporary storage location which allows the transmitter and receiver to store the data until the information is processed by each other at different speeds.

What is Handshaking? Handshaking is the process of interchanging information signals between the sender (transmitter) and receiver. These signals build a communication link between the transmitter and receiver. In RS232, there are two types of handshaking. They are hardware handshaking and software handshaking. To use the handshaking technique, RTS and CTS are cross-coupled. Also, DTR and DSR are also connected in cross mode.

Straight-through cable It is a one to one connector, i.e. a transmit pin of one device is connected to transmit pin of another device and receiver pin of one device is connected to receiver pin of another device. 

Types of Serial Cables Null Modem Cable In null modem cable, the TX (Transmitter) pin of the male connector is linked up with the RX (Receiver) pin of the female and the RX pin of the male is connected to TX pin of the female.

Communication Interface RS232 determines the communication between the DTE and DCE using DB9 and DB25 connectors. 

Electrical Standards Voltage Levels The line voltages of RS232 range from -25V to +25V. They are categorized as signal voltage and control voltage. Slew Rate The change of input voltage determines the rate at which the RS232 driver responds. This is often termed as slew rate . Normally, the maximum slew rate allowed is 30V/µsec. Line Impedance The impedance bridging between RS232 driver and the receiver is defined to maximize the voltage transfer between the transmitter and receiver. It is in the range of 3KΩ to 7KΩ. Baud rate It is the number of binary bits transferred per second. RS232 supports baud rates from 110 to 230400. Commonly, the baud rate with 1200, 4800, 9600, 115200 are used. 

What is RS232 Protocol? In RS232, ‘RS’ stands for Recommended Standard. It defines the serial communication using DTE and DCE signals. Here, DTE refers to Data Terminal Equipment and DCE refers to the Data Communication Equipment. Example of DTE device is a computer and DCE is a modem.